Search

Purpose: Continuous positive airway pressure (CPAP) is the primary therapy for obstructive sleep apnea (OSA); however the effectiveness of CPAP remains suboptimal. We describe the Novel PhysIologiC prEdictors of Positive Airway Pressure Effectiveness (NICEPAP) study. Its purpose is to determine whether physiological traits of OSA contribute to CPAP effectiveness. Methods: NICEPAP (NCT05067088) is a prospective, observational cohort study conducted at an academic sleep center. Adults newly diagnosed with OSA (n = 267) are assessed for OSA traits of loop gain, arousal threshold, pharyngeal collapsibility, and muscle compensation from baseline polysomnography. We perform a comprehensive assessment of covariates relevant to CPAP adherence, efficacy, and patient-centered outcomes. Participants are followed for 12 months. Primary outcomes include (1) CPAP adherence (hours/night), (2) CPAP efficacy (apneas-hypopneas/hour), and (3) quality of life at six months measured by objective CPAP data and Functional Outcomes of Sleep Questionnaire. Secondary outcomes include sleep quality, sleepiness, insomnia, and neurocognitive function. Results: Data on covariates, including demographics, sleep symptoms, medical history, medications, sleep quality, OSA and treatment self-efficacy, decisional balance, and socio-economic and social and partner support, are collected using validated instruments. The analysis for primary outcomes includes a generalized linear mixed model for an outcome (e.g., CPAP adherence) with OSA traits as exposures followed by the addition of relevant covariates. Conclusion: The findings of the NICEPAP study will inform research aimed to enhance CPAP effectiveness. Understanding the role of physiological OSA traits in CPAP effectiveness is a crucial step toward a precision medicine approach to OSA. [ABSTRACT FROM AUTHOR]

The impact of biochar application on plant performance under drought stress necessitates a comprehensive understanding of biochar–soil interaction, root growth, and plant physiological processes. Therefore, pot experiments were conducted to assess the effects of biochar on plant responses to drought stress at the seedling stage. Two contrasting maize genotypes (drought-sensitive KN5585 vs. -tolerant Mo17) were subjected to biochar application under drought stress conditions. The results indicated that biochar application decreased soil exchangeable Na+ and Ca2+ contents while increased soil exchangeable K+ content (2.7-fold) and electrical conductivity (4.0-fold), resulting in an elevated leaf sap K+ concentration in both maize genotypes. The elevated K+ concentration with biochar application increased root apoplastic pH in the drought-sensitive KN5585, but not in the drought-tolerant Mo17, which stimulated the activation of H+-ATPase and H+ efflux in KN5585 roots. Apoplast alkalinization of the drought-sensitive KN5585 resulting from biochar application further inhibited root growth by 30.7%, contributing to an improvement in water potential, a reduction in levels of O2–, H2O2, T-AOC, SOD, and POD, as well as the down-regulation of genes associated with drought resistance in KN5585 roots. In contrast, biochar application increased leaf sap osmolality and provided osmotic protection for the drought-tolerant Mo17, which was associated with trehalose accumulation in Mo17 roots. Biochar application improved sucrose utilization and circadian rhythm of Mo17 roots, and increased fresh weight under drought stress. This study suggests that biochar application has the potential to enhance plant drought tolerance, which is achieved through the inhibition of root growth in sensitive plants and the enhancement of osmotic protection in tolerant plants, respectively. Biochar application decreased soil exchangeable Na+ and Ca2+, but increased soil exchangeable K+ and electrical conductivity. Biochar increased apoplastic pH, but reduced root growth, stress damage and stress response during drought for the drought-sensitive KN5585. Biochar improved osmotic protection, trehalose accumulation, and fresh weight during drought for the drought-tolerant Mo17. [ABSTRACT FROM AUTHOR]

Key message: This study not only provide a theoretical basis for screening drought-resistant yellowhorn rootstocks but also lay the foundation for the research on the drought resistance mechanism of yellowhorn. Drought is a major limiting factor in the production and cultivation of yellowhorn, an important woody oil species in China. It is important to select excellent drought-resistant rootstocks, and the current reproduction of rootstocks of yellowhorn is mainly through seed propagation. In this study, we analyzed the phenotypes, physiology and anatomy of the F1 generation of five yellowhorn varieties ('Zhongshi 1', 'Zhongshi 4', 'Zhongshi 7', 'Zhongshi 9' and 'Yuanda') which are currently the main promoted varieties of yellowhorn. The changes in physiological traits were used to comprehensively rank drought resistance by the membership function method. The results showed that the drought resistance of different varieties was in the order 'Zhongshi 9' > 'Zhongshi 4' > 'Yuanda' > 'Zhongshi 7' > 'Zhongshi 1'. In addition, we investigated the molecular signature of two yellowhorn varieties exhibiting a large difference in levels of drought resistance using transcriptome data. A total of 119 differentially expressed genes (DEGs) were found between the 2 yellowhorn varieties under drought stress. Based on KEGG analysis, DEGs were mostly enriched in three pathways. According to the correlation analysis between weighted gene co-expression network analysis (WGCNA) and physiological traits, a total of four co-expression networks with high correlation were constructed, and some hub genes of yellowhorn in response to drought stress were found. We carried out a comprehensive evaluation of yellowhorn drought tolerance based on parental lines. It solves the current problems faced in the breeding of yellowhorn and lays the foundation for studying the molecular mechanism of drought resistance in yellowhorn. [ABSTRACT FROM AUTHOR]

Nitrogen (N) is an essential element for plant growth, and its deficiency influences plants at several physiological and gene expression levels. Barley (Hordeum vulgare) is one of the most important food grains from the Poaceae family and one of the most important staple food crops. However, the seed yield is limited by a number of stresses, the most important of which is the insufficient use of N. Thus, there is a need to develop N-use effective cultivars. In this study, comparative physiological and molecular analyses were performed using leaf and root tissues from 10 locally grown barley cultivars. The expression levels of nitrate transporters, HvNRT2 genes, were analyzed in the leaf and root tissues of N-deficient (ND) treatments of barley cultivars after 7 and 14 days following ND treatment as compared to the normal condition. Based on the correlation between the traits, root length (RL) had a positive and highly significant correlation with fresh leaf weight (FLW) and ascorbate peroxidase (APX) concentration in roots, indicating a direct root and leaf relationship with the plant development under ND. From the physiological aspects, ND enhanced carotenoids, chlorophylls a/b (Chla/b), total chlorophyll (TCH), leaf antioxidant enzymes such as ascorbate peroxidase (APX), peroxidase (POD), and catalase (CAT), and root antioxidant enzymes (APX and POD) in the Sahra cultivar. The expression levels of HvNRT2.1, HvNRT2.2, and HvNRT2.4 genes were up-regulated under ND conditions. For the morphological traits, ND maintained root dry weight among the cultivars, except for Sahra. Among the studied cultivars, Sahra responded well to ND stress, making it a suitable candidate for barely improvement programs. These findings may help to better understand the mechanism of ND tolerance and thus lead to the development of cultivars with improved nitrogen use efficiency (NUE) in barley. [ABSTRACT FROM AUTHOR]

Aims: Copper (Cu) is essential for enzymatic systems, electron transport during photosynthesis, and lignin synthesis, affecting plant metabolism and growth. Cu deficiency is observed in young tree orchards, possibly induced by interaction with other mineral nutrients, although visual symptoms are not easily characterized. This study evaluated the induction of Cu deficiency in citrus, due to high nitrogen (N) fertilization, based on the assessment of biochemical parameters, gas exchange, and anatomy of plant tissues. Methods: Valencia orange trees were submitted to levels of Cu supply via fertigation in addition to foliar spraying (control without Cu or with 2.4 g plant−1 of Cu), and N (medium = 8.6 or high = 25.9 g plant−1 of N) for 210 days. Results: Plants well supplied with Cu exhibited higher electron transport rate, net CO2 assimilation, transpiration, and stomatal conductance, in comparison to the control without Cu. Those grown with high N exhibited greater electron transport rate compared to medium N. Plants without Cu and high N supply exhibited the lowest nitrate reductase activity, whereas plants fertilized with Cu and high N exhibited the greatest increase in the activity of this enzyme, in addition to the highest levels of total free amino acids. Furthermore, plants without Cu and high N exhibited the lowest Cu/Zn-SOD II isoform activity. Loose parenchyma structures of leaves and branches were associated with visual symptoms of Cu deficiency. Conclusion: Plant responses demonstrated how Cu deficiency is induced in citrus trees by excess N, thus highlighting the importance of establishing best nutrient management for sustainable fruit production. [ABSTRACT FROM AUTHOR]

Drought stress is a significant constraint that affects the yield of almost all major crops. Its impact is expected to worsen due to global climate change and human population expansion. Potato (Solanum tuberosum L.) is the third most important food crop worldwide, but it is highly susceptible to drought stress. In order to understand the effects of drought stress on yield and identify traits for selecting drought-tolerant potato genotypes, we evaluated the response of a range of agronomic and physiological traits in 15 potato genotypes under well-watered (WW) and water deficit (WD) conditions. The harvest index (HI) was found to have a high plot-based heritability (0.98), indicating that it can be used for the indirect selection of drought-tolerant genotypes. In contrast, SPAD was sensitive to detecting early drought stress in potatoes. Drought-tolerant genotypes, including CIP392797.22 (UNICA), CIP397077.16, CIP398190.89, CIP398208.219, and CIP398208.620, were able to allocate limited water towards tuber production rather than biomass. These genotypes showed high tuber production under WW conditions and increased photosynthetic activity and water use efficiency under WD conditions. [ABSTRACT FROM AUTHOR]

An immediate concern of commercial tree plantation is the depleting water resource and drastic change in climatic conditions, which adversely affect the biomass productivity. Maximizing productivity from the available water and nutrient resources is presently the focus of most tree breeding and plantation programs. In Eucalyptus species variations in response to water deprived conditions are reported between species, among provenances and between clones. In the present study, 126 clones derived from the breeding program of Eucalyptus camaldulensis James. and Eucalyptus tereticornis sm. were screened for their response to progressive dehydration stress under controlled environmental conditions and morpho-physiological changes were recorded. Specific Leaf Area (SLA) and Relative Water Content (RWC) were found to be effective dehydration stress indices in both the species. Drought Susceptibility Index (DSI) which measures the decrease in yield of a genotype under drought conditions with respect to mean reduction of all genotypes studied, is a major selection criteria and quantitative indicator in selecting varieties for dehydration tolerance. DSI was recorded for each measured traits and SLA–DSI and RWC–DSI clustered the clones based on their tolerance/ susceptibility to dehydration stress. Additionally, ten prospective clones were selected as dehydration tolerant genotypes and are probable candidates for future multi-environment evaluation under arid and semi-arid conditions for deployment in plantation and breeding programs. [ABSTRACT FROM AUTHOR]

Drought stress remains one of the most detrimental environmental constraints that hampers plant growth and development resulting in reduced yield and leading to economic losses. Studies have highlighted the beneficial role of carbon-based nanomaterials (NMs) such as multiwalled carbon nanotubes (MWNTs), single-walled carbon nanotubes (SWNTs), graphene, fullerene, and metal-based nanoparticles (NPs) (Ag, Au, Cu, Fe2O3, TiO2, and ZnO) in plants under unfavorable conditions such as drought. NPs help plants cope with drought by improving plant growth indices and enhancing biomass. It improves water and nutrient uptake and utilization. It helps retain water by altering the cell walls and regulating stomatal closure. The photosynthetic parameters in NP-treated plants reportedly improved with the increase in pigment content and rate of photosynthesis. Due to NP exposure, the activation of enzymatic and nonenzymatic antioxidants has reportedly improved. These antioxidants play a significant role in the defense system against stress. Studies have reported the accumulation of osmolytes and secondary metabolites. Osmolytes scavenge reactive oxygen species, which can cause oxidative stress in plants. Secondary metabolites are involved in the water retention process, thus improving plant coping strategies with stress. The deleterious effects of drought stress are alleviated by reducing malondialdehyde resulting from lipid peroxidation. Reactive oxygen species accumulation is also controlled with NP treatment. Furthermore, NPs have been reported to regulate the expression of drought-responsive genes and the biosynthesis of phytohormones such as abscisic acid, auxin, gibberellin, and cytokinin, which help plants defend against drought stress. This study reviewed 72 journal articles from 192 Google Scholar, ScienceDirect, and PubMed papers. In this review, we have discussed the impact of NP treatment on morphological, physio-biochemical, and molecular responses in monocot and dicot plants under drought conditions with an emphasis on NP uptake, transportation, and localization. [ABSTRACT FROM AUTHOR]

Drought stress is a major abiotic factor that frequently suppresses crop growth at various stages. The main ambition behind this current work is to check the influence of foliar applied silicon @50 ppm at flag leaf stage on three oat cultivars (IST, S-85/Sl and PARC) under three different field capacities (100% FC, 75% FC and 50% FC). Data about antioxidants enzymes including SOD (Superoxide dismutase), CAT (Catalase), proline compatible solutes and MDA (Malondialdehyde) accumulation was collected at flag leaf stage. Similarly, relative water content (RWC), excised leaf water loss (ELWL), membrane thermo-stability index (MTSI), SPAD chlorophyll and leaf area index (LAI) were determined. The given outcomes proved that silicon helped to minimize the harmful effect of drought by increasing proline (by 43%) as well as SOD (by 46%), CAT (by 52%) and decreasing the MDA (by 61%) in oat-tested cultivars. Moreover, Si application resulted to lowering of MTSI (by 12%) and ELWL (by 12%) while it helped to increase RWC (13%). Furthermore, LAI and chlorophyll (29%) were significantly increased with silicon application. The obtained results showed that silicon treatment could help to augment the harmful effect of water stress and mitigate this stress in different crops. Our research work provided the comprehensive note on physio-chemical properties of all oat cultivars under water stress conditions treated with silicon. This research work clearly showed that silicon could be used to mitigate water stress by maintaining leaf water balance under drought stress condition. [ABSTRACT FROM AUTHOR]

Disease management with the use of conventional pesticides has emerged as a major threat to the environment and human health. Moreover, the increasing cost of pesticides and their use in staple crops such as rice is not economically sustainable. The present study utilized a combination of two commercial powder formulations of biocontrol agents, Trichoderma harzianum (Th38) and Pseudomonas fluorescens (Pf28) to induce resistance against sheath blight disease via seed biopriming in basmati rice variety Vasumati and compared the performance with systemic fungicide carbendazim. Sheath blight infection significantly increased the levels of stress indicators such as proline (0.8 to 4.25 folds), hydrogen peroxide (0.89 to 1.61 folds), and lipid peroxidation (2.4 to 2.6 folds) in the infected tissues as compared to the healthy control. On the contrary, biopriming with biocontrol formulation (BCF) significantly reduced the level of stress markers, and substantially enhanced the levels of defense enzymes such as peroxidase (1.04 to 1.18 folds), phenylalanine ammonia lyase (1.02 to 1.17 folds), lipoxygenase (1.2 to 1.6 folds), and total phenolics (74% to 83%) as compared to the infected control. Besides, improved photosynthesis (48% to 59%) and nitrate reductase activity (21% to 42%) showed a positive effect on yield and biomass, which compensated disease induced losses in bio-primed plants. Conversely, the comparative analysis of the efficacy levels of BCF with carbendazim revealed BCF as a potential and eco-friendly alternative for reducing disease impact and maintaining higher yield in rice under sheath blight infection. [ABSTRACT FROM AUTHOR]

Origanum vulgare L. is a valuable flavoring, mainly due to its important essential oils and is widely used in different industries. This study aimed to compare the expression level of genes coding for proteins involved in rosmarinic acid (RA) biosynthesis pathway and some physiological responses in O. vulgare under two levels of salinity (2, 4 decisiemens/meter (dS/m), and 0 as a control), two levels of Methyl Jasmonate (MeJA) (0.1, 0.5 mM, and 0 as a control), and a consortium of three bacteria (Azotobacter chroococcum, Azospirillium brasilense, and Pseudomonas fluorescens). The results showed that salinity negatively affected RA induction and rosmarinic acid synthase (RAS) gene expression and positively influenced DPPH radical scavenging capacity at all treatments. The combined application of bacterial consortium and 0.1 mM MeJA in absence of salinity showed 6.6- and 3.37-fold cinnamic acid 4-hydroxylase (C4H), RAS genes expression, respectively, compared to control. Application of bacterial consortium and 0.1 mM MeJA also increased RA induction (6.47 mg/g), total phenolic content (6.79 mg GAE/g), and positively affected all biochemical and physiological treats in O. vulgare. MeJA in concentration of 0.5 mM even with bacteria inoculation had negative effect on RA production. The RAS gene may be more responsible for controlling RA induction compared to C4H gene. Further studies are needed to identify all genes involved in RA production in O. vulgare. Our results may be used to improve RA production and tolerance mechanisms of O. vulgare under salinity conditions. [ABSTRACT FROM AUTHOR]

Thermal stress is a major abiotic stress in wheat and is highly complex in mechanism. A large area in northwestern plain zones (NWPZ), which is the wheat bowl of India is affected by heat stress. Climate change also causes an abrupt increase in temperature at different growth stages of wheat. Thus, wiser selection of stress tolerant varieties is an important strategy to combat the climate change effect. The present study aims for physiological and biochemical screening of timely sown NWPZ wheat varieties (WB2, HD3086, DBW88, DPW621-50, DBW17, HD2967 and PBW550) of India for their thermal stress tolerance along with heat tolerant (RAJ3765) and susceptible checks (RAJ4014) at seedling stage. The experiment was conducted in completely randomized design under controlled laboratory condition and heat stress was induced at 37 °C at seedling stage. Later different physio-biochemical traits were studied in both control and stress seedlings. All traits exhibited significant variations among genotypes under heat stress condition. Root and shoot weight, relative water content, chlorophyll content index and chlorophyll fluorescence reduced significantly, whereas membrane leakage, osmotic potential, catalase, ascorbate peroxidase, guaiacol peroxidase, malondialdehyde content and proline content were increased in stress plants. A tolerance matrix was prepared based on stress response of the genotypes for each trait and a final tolerance score was given to each genotype. Based on this tolerance matrix, DBW88 and PBW550 were identified as tolerant, DPW621-50, DBW17 and HD2967 as moderately susceptible and HD3086 and WB2 as susceptible to heat stress. Earlier studies parade that seedling level stress tolerance has high correlation with adult level stress tolerance under field condition in wheat. Hence, this study helps in wiser selection of varieties for sowing in NWPZ based on weather forecast of the location for creating varietal mosaic in context of climate change. [ABSTRACT FROM AUTHOR]

Herbivorous molluscs represent one of the greatest grazing impacts on abundance and diversity of primary producers in benthic ecosystems. However, the effects of nutritional content of kelp species on the physiological rate of trochoid herbivorous snails inhabiting intertidal-subtidal environments are less well known. Here, we conducted manipulation experiments to compare the nutritional quality of two kelp species, Lessonia spicata and Macrocystis pyrifera, and their influence on the feeding behavior and physiological rates of the snail Tegula atra. Experimental results demonstrated that L. spicata had the highest nutritional value (i.e., high organic matter and protein content), and was the preferred alga, compared with M. pyrifera in a choice experiment. However, when the snails were raised with each of the algal species in no choice experiments, no significant differences were found. Absorption efficiency and oxygen uptake were higher for snails reared with L. spicata than M. pyrifera, but growth rate was similar. These results suggest that high metabolic activity was compensated by the high absorption efficiency of T. atra when it consumed the preferred L. spicata, which could explain the lack of relationship between preference and growth rate. [ABSTRACT FROM AUTHOR]

Delay sowing of wheat is a common problem in Punjab that exacerbates serious yield loss. To reduce yield loss and improve yield, different combinations of foliar-applied bioregulator and micronutrients, control (CK), zinc (Zn), boron (B), thiourea (TU), Zn + B (ZnB), Zn + TU (ZnTU), B + TU (BTU), Zn + B + TU (ZnBTU) were applied at booting and grain filling stages in delayed sown wheat in 2017–18 and 2018–19. The results showed that ZnBTU treatment significantly increased leaf area index by 25.06% and 23.21%, spike length by 15.11% and 19.65% in 2017 and 2018, respectively, compared to CK. The ZnBTU treatment also increased 1000-grain weight by 21.96% and 22.01% in 2017 and 2018, respectively, compared to CK. Similarly, higher Zn, B and N contents in straw and grain were recoded for ZnBTU treatment which was statistically similar to ZnB and ZnTU treatments. Overall, ZnBTU treatment also increased the photosynthetic rate, transpiration rate, stomatal conductance by 46.67%, 26.03%, 76.25% and decreased internal CO2 by 28.18%, compared to CK, respectively. Moreover, ZnBTU also recorded the highest grain yield in 2017–18 (25.05%) and 2018–19 (28.49%) than CK. In conclusion, foliar application of ZnBTU at the booting and grain filling stages of delayed sown wheat could be a promising strategy to increase grain yield. [ABSTRACT FROM AUTHOR]

Pinus elliottii × P. caribaea is a widely planted commercial tree hybrid in South China. To investigate the potential of physiological parameters for clonal selection, cuttings of three clones (EH3, EH4 and EH5) and a control were grown in phosphorus treated pots. Significant variations to phosphorous, photosystem II activity and polar metabolite abundance in needles were noted among clones. Clone EH5 was the most P-responsive and had maximum height growth. The highest maximum quantum yield of PSII in the dark (Fv/Fm), maximum quantum yield of PSII in the light (Fvʹ/Fmʹ) and the actual PSII efficiency (ΦPSII) values were also found in EH5. A total of 64 polar metabolites were identified, 21 were regulated by phosphorous, while 28 accumulated differentially among the three clones. There were few overlapping responsive metabolites to phosphorous fertilization. In EH5, the abundance of maltotriitol, neohesperidin and raffinose were highest, whereas galactinol and shikimic acid were lower compared with EH3 and EH4. The results reveal that physiological traits were genetically controlled and might be useful for selecting clones with high phosphorous utilization efficiency. [ABSTRACT FROM AUTHOR]

Background: Potato (Solanum tuberosum L.), the world's third most important crop, is frequently thought to be sensitive to moderately sensitive to drought, and yield has fallen considerably over consecutive stress periods. Drought produces a wide range of responses in potato, from physiological alterations to variations in growth rates and yield. Knowledge about these responses is essential for getting a full understanding of drought-tolerance mechanism in potato plants which will help in the identification of drought-tolerant cultivars. Results: A set of 21 commercial potato cultivars representing the genetic diversity in the Middle East countries market were screened for drought tolerance by measuring morpho-physiological traits and tuber production under in vitro and field trials. Cultivars were exposed to drought stress ranging from no drought to 0.1, 0.2 and 0.3 mol L−1 sorbitol in in vitro-based screening and 60, 40 and 20% soil moisture content in field-based screening. Drought stress adversely affected plant growth, yield and cultivars differed for their responses. Shoots and roots fresh weights, root length, surface area of root, no. of roots, no. of leaves, leaf area, plant water content %, K+ content, under in vitro drought treatments and shoots fresh and dry weights, no. of tubers and tuber yield under field drought treatments were examined and all decreased due to drought. The stress tolerance index decreased with increasing drought in examined cultivars; nevertheless, it revealed a degree of tolerance in some of them. Grouping cultivars by cluster analysis for response to drought resulted in: (i) a tolerant group of five cultivars, (ii) a moderately tolerant group of 11 cultivars, and (iii) a sensitive group of five cultivars. Furthermore, stress-related genes, i.e., DRO, ERECTA, ERF, DREB and StMYB were up-regulated in the five cultivars of the tolerant group. Likewise, the stomatal conductance and transpiration explained high correlation with the tuber yield in this group of cultivars. Conclusion: The diversity in germplasm indicated that potato cultivars can be developed for production under certain degrees of drought. Some cultivars are good candidates to be included in drought-tolerant breeding programs and recommended for cultivation in drought-stricken regions. [ABSTRACT FROM AUTHOR]

The current study aimed to investigate responses of fennel (Foeniculum vulgare Mill) plants to salt stress through foliar spray of salicylic acid (SA) as priming agent. SA (0, 0.5 mM) was sprayed on three Iranian populations (Bonab, Hamedan, Moghan) and two foreign populations (German, Gaziantep) three days before imposing salinity (0, 100, 200 mM) and some agronomical and physiological traits were assayed in leaves to determine SA effect as chemical priming agent. Salinity decreased agronomic traits, chlorophyll (Chl) a, b, total Chl, carotenoids and K+, K+/Na+ ratio and increased Na+, malonyldialdehyde (MDA), hydrogen peroxide (H2O2) and total soluble sugar (TSC) in all populations. Fennel populations showed positive responses to SA application regarding the mentioned characters under non-stress and stress conditions through reversing the salinity impacts on the measured parameters. Regarding the obtained results, German and Moghan populations could be considered as the resistant and sensitive populations. In conclusion, SA application as chemical priming could alleviate salt stress effects on fennel populations representing its effectiveness in this regard. [ABSTRACT FROM AUTHOR]

Ninety landraces of rice were evaluated for various physio-morphological traits in completely randomized design with two treatment levels, i.e. control and high-temperature stress (3–5 °C) more than the ambient condition with three replications each. The high-temperature stress was induced from panicle initiation to maturity stage by keeping the pots in a temperature-controlled green house facility. High values of genotypic coefficient of variability, phenotypic coefficient of variability, heritability and genetic advance were found for the traits number of unfilled grains/panicle and number of filled grains/panicle, indicating the pre-ponderance of additive gene action and, therefore, scope for improvement of the trait through selection. Four principle components were depicted having Eigen value > 1 and cumulative variation of 59.84%. Based on the performances of various physio-morphological traits under control and heat stress conditions, we were able to identify Karuthacheera, LN-9956-Vellakaravala (Pavumba) and Pokkali white were recorded the highest number of fertile grains under high temperature. [ABSTRACT FROM AUTHOR]

The rise in human population necessitates the use of all available tools to enhance wheat productivity. In this regard, pre-breeding has mobilized novel underutilized genetic variation into breeding programs. However, this germplasm needs to be characterized for its efficient utilization. This investigation was initiated to evaluate the early and late sown wheat pre-breeding germplasm for physiology- and yield-related traits and to associate the mapped SNPs using association mapping approach. Our results indicate that the germplasm performed better in early sowing in comparison to late planting where grain yield (Yd) was found positively correlated with water use efficiency (WUE), heading time, and chlorophyll contents (Chl). We discovered a total of 210 associations involving 155 SNPs. Taking into consideration either early or late sowing and the mean values, only 12 marker traits were associated with trait germination, plant height, stomatal conductance, transpiration rate, Chl, carotenoids, and Yd. Our correlations and mapping results indicate that higher WUE along with Chl can be targeted as indirect physiological markers to enhance wheat yield. [ABSTRACT FROM AUTHOR]

Breeding of heat-tolerant cultivars requires knowledge of the genetic behavior of morpho-physiological traits. Gene action was investigated using wide phenotypic segregation ranging across six generations (P1, P2, F1, BC1, BC2 and F2) of four different tolerant × sensitive crosses for grain filling duration, GFD (40.14–46.20); canopy temperature depression, CTD (2.42–5.97); normalized difference vegetation index, NDVI (0.35–0.61); membrane thermostability index, MSI (31.40–40.93); no. of grains/spike, GN/SP (26.29–54.80); thousand-grain weight, TGW (31.70–44.45); and grain yield/plant, GY (15.37–24.89) under terminal heat stress. Scaling results indicated an absence of epistasis for MSI and TGW in cross PBN51 × HUW510. The prominence of Dominance × dominance interaction over additive × additive and additive × dominance interactions along with significant dominant gene effect [h] for all traits except MSI was observed. For MSI, similar signs of [d] and [i] along with significant [j] showed the possibility of exploitation of additive gene effect. CTD, NDVI and GN/SP were controlled by duplicated epistasis, whereas both complementary and duplicate epistasis was found for GFD. Digenic interactions with prominent duplicate epistasis indicate that biparental mating or diallel selective mating might be efficiently utilized for their improvement. The present investigation indicated a preponderance of non-additive gene action for studied traits, thus, implying toward delaying of selection to the later generations to exploit transgressive segregants. Any conventional breeding strategy would be followed for generating the cultivars with low CTD, reduced cell membrane injury, with higher NDVI, TGW, GFD, no. of grains/spike and grain yield/plant. [ABSTRACT FROM AUTHOR]

Given a critical water scarcity in arid and semi-arid Tunisian areas and aiming to reduce irrigation water request, it is crucial to identify and apply the best water-saving practices in these irrigated areas. Tomato is a high-water-requiring vegetable crop, thus increasing the pressure on water resources and environment. Its sustainable cultivation in such alarming conditions requires an adaptation of on-farm irrigation water-saving strategies preserving also the crop yield and leading to a fruit quality improvement. This study aimed to explore the effects of the regulated deficit irrigation (RDI) as an irrigation water-saving strategy, on yield, fruit quality, and physiological behavior of greenhouse grown potted tomato crop (Solanum lycopersicum L.) during three identified growth stages. The managed water regimes were (i) full irrigation (FI) ensuring 100% of the estimated water crop requirements, (ii) RDI1-25 and RDI1-50 ensuring respectively 75% and 50% of FI water supplies during the vegetative crop stage (stage I), (iii) RDI2–25 and RDI2–50 ensuring respectively 75% and 50% of FI water supplies from first truss blossom until first harvest (stage II), and (iv) RDI3-25 and RDI3-50 ensuring respectively 75% and 50% of FI supplies during the rest of the harvest period (stage III). The results showed that the substrate moisture vary significantly with the water deficit regime applied under different growth stages, thus providing different levels of substrate water content. Under RDI2, the tomato yield was the highest when compared with FI, RDI1, and RDI3 regimes. Indeed, saving the water by 20% under RDI2-50 reduced only 3% of tomato yield. Deficit irrigation under ripening fruit and flowering stages, mainly with 50% of water supplies shortage, resulted in higher fruit skin color, firmness, and refractometry index (°Brix) when compared to FI and RDI1. Physiological traits measurements indicated that FI exhibited the highest leaf stomatal conductance (gs) and chlorophyll index (CI) values while RDI3 exhibited the lowest gs and CI values among all the RDI treatments. Results are valuable in considering gs and CI as an efficient indicators of tomato plant water status. The results are also an important contribution to identify the second tomato growth stage as the best period that tomato plant tolerate water shortage without significant yield decrease, as well a rather fruit quality improvement. These results help to reach the challenge "more crop per drop" and can contribute to water scarcity remediation. [ABSTRACT FROM AUTHOR]

To study the impact of terminal moisture stress, thirty-one genotypes of mungbean were screened under irrigated and moisture stress at pod filling stage during summer 2013–2014 in randomized block design. Mean performance revealed RMG 492 and GVIT-203 as best genotypes under irrigated and moisture stress, respectively. Individual and combined ANOVA revealed significant difference among the genotypes. The genotype-trait (GT) biplot analysis was done using multiple traits for irrigated and moisture stress separately. The polygon view of GT biplot revealed that AKM 9904, IPM-02-19, LGG 528, PUSA VISHAL and RMG 492 in irrigated condition; RMG 492 and GVIT-203 in moisture stress as best genotypes. The genotypes VG-6197A, IPM-02-19, COGG 974, ML 145 and PUSA 9531 under irrigated condition; EC-396117, RMG 492 and VG-6197A under moisture-stress condition are close to ideal genotypes. The harvest index (HI) was identified as the best and stable trait for all genotypes under both irrigated and moisture-stress conditions. The relationship among characters showed that seed yield per plant is positively associated with HI and relative water content under both irrigation regimes. The seed yield per plant and specific leaf area are more discriminative under both conditions, whereas SCMR and chlorophyll content are more representatives under irrigated and moisture stress, respectively. The genotypes RMG 492 and VG-6197A identified in this study could be used in different breeding programs and traits SCMR and harvest index portrayed in this study can be used for screening of moisture-stress tolerance in different selection processes. [ABSTRACT FROM AUTHOR]

Aim: We estimated how seasonality in conjunction with key climatic variables affects morphological and physiological plant functional traits (PFTs) and soil essential (micro and macro) nutrients in oak, pine, and mixed forests. Method: The different PFTs were tested using several laboratory methods and using the portable photosynthesis system Li-COR 6400 XT, Lincoln NE, USA. Likewise, some chemical traits and soil nutrients were analyzed by using CHNS analyzer. Results: In this study, physiological traits such as CO2 assimilation rate, stomatal conductance and transpiration rate were significantly higher in the rainy season followed by summer and winter seasons. Among the different forest land uses, physiological traits and resource use efficiency have been significantly higher in oak forest (OF) compared to the mixed forest (MF) and pine forest (PF). Likewise, the concentration of macro–micro nutrients was also recorded higher during the rainy season. The concentration of macro–micro nutrients was higher in OF than in MF and PF in different forest land uses. Conclusion: Changes in PFTs ultimately affect the ecosystem services imparted by the different forests. Such changes lead to the local adaptation of these forests through the interaction between PFTs and soil nutrients. [ABSTRACT FROM AUTHOR]

Leaves of trees experience the maximum brunt of exposure and undergo certain changes in physiological traits responding to air pollution, and then, the specific leaf traits can be the indicators of air pollution in an area. However, due to the diversity of sources, the composition of air pollutants is very complex. This makes it difficult to predict air pollution using physiological differentiation of leaves. The purpose of this investigation was to examine potential of Ligustrum lucidum Ait. leaf measurement as a method to predict the air pollutants in Luoyang, China. Leaves of roadside L. lucidum were studied from the city center with serious air pollution to relatively unpolluted areas. Leaf size, stomatal traits, and non-structural carbohydrate were measured. The particulate and gaseous pollutants (including sulfur dioxide, nitrogen dioxide, carbon monoxide, and ozone) were investigated too. The results showed that the leaf area and soluble sugar content decreased, while the aspect ratio of leaves increased in heavily polluted areas. As pollution increased, the stomatal traits in different crown positions were changed differently. No significant correlation was found between ozone content and the measured traits of leaves. The responses found in the physiological differentiation of the leaves reflect acclimation to air pollution. The soluble sugar content of the leaves could be used to indicate the short-term stress of air pollution, the area, and aspect ratio of leaves are indicative of the long-term stress due to air pollution. Therefore, physiological traits of L. lucidum leaves appeared to be significant predictive factors for the air pollutants in urban areas. [ABSTRACT FROM AUTHOR]

Background: Salinity is one of the major limiting abiotic stresses that decrease crop production worldwide. To recommend genotypes for cultivation under saline stress conditions, a comprehensive understanding of the genetic basis and plant responses to this stress is needed. In the present study, a total of 20 barley genotypes were investigated to identify potential salt-tolerant genotypes, both at the early growth stage using a hydroponic system, and in adult plants under field conditions. For these purposes, the multi-trait genotype-ideotype distance index (MGIDI) was used to identify salt-tolerant barley genotypes at the seedling stage, and the weighted average of absolute scores (WAASB) index was used to identify the high-yielding and stable genotypes in adult plant stage. At the early growth stage, barley seedlings were treated with two salinity levels: 0 mM NaCl (as control conditions) and 200 mM NaCl (as stress conditions) for 30 days, and during this period different growth and physiological traits were measured. Besides, the yield performance and stability of the investigated barley genotypes were evaluated across five environments during the 2018–2020 cropping seasons. Results: Salinity stress significantly decreased growth and physiological traits in all seedling plants; however, some salt-tolerant genotypes showed minimal reduction in the measured traits. Multivariate analysis grouped the measured traits and genotypes into different clusters. In the early growth stage, the G12, G14, G6, G7, and G16 were selected as the most salt-tolerant genotypes using MGIDI index. In the multi-environment trials experiment, AMMI analysis showed that grain yields of the tested barley genotypes were influenced by the environment (E), genotype (G), and GE interaction. Based on the weighted average of absolute scores of the genotype index (WAASB) and other stability statistics, G7, G8, G14, and G16 were selected as superior genotypes. Conclusion: Together the MGIDI and WAASB indices revealed that three genotypes—G7, G14 and G16—can be recommended as new genetic resources for improving and stabilizing grain yield in barley programs for the moderate climate and saline regions of Iran. Our results suggest that using the MGIDI index in the early growth stage can accelerate screening nurseries in barley breeding programs. Besides, the WAASB index can be used as a useful stability measurement for identify high-yielding and stable genotypes in multi-environment trials. [ABSTRACT FROM AUTHOR]

Temperature inducible phenotypic plasticity is a major player in plant responses to climate warming. Functional responses and their role in determining thermal plasticity of plants remain poorly understood. Our objective was to compare trait responses of six populations of Ludwigia peploides resulting from seed from Oceanic climate and from Mediterranean climate after an exposure at three temperatures (16, 24, and 30°C). A comparative analysis showed that at 30°C, the six populations of L. peploides shared different morphological responses, whereas a common pattern of morphological responses was found for the six populations at 16°C. At 16°C, the growth was very low suggesting a stress. At 30°C, the three Mediterranean populations of L. peploides accumulated ≈ sevenfold more total biomass than the populations from Oceanic region. Despite drawing similar response pattern to temperature, the populations showed several different metabolic responses. The thermal plastic responses to the highest temperature differed according to the origin of the populations. The Mediterranean populations of L. peploides could be better adapted to rising temperature. These abilities could allow them to take advantage from climate warming if the temperature is not warming up to temperature above a critical threshold. [ABSTRACT FROM AUTHOR]

Dust is a feature of the natural environment that can be exacerbated by anthropogenic activities. A range of physiological impacts have been attributed to dust deposition on plant leaves, including altered gas exchange and reduced photosynthetic activity—traits associated with yield and overall productivity. Substantially increased traffic along rural unpaved roads following the development of shale petroleum deposits in the Bakken region of North Dakota, USA, prompted us to investigate the effect of heavy dust exposure on economically important annual crops and perennial forage grasses. In a greenhouse study, we exposed six species of annual plants (barley Hordeum vulgare, durum wheat Triticum durum, maize Zea mays, sorghum Sorghum bicolor, lentil Lens culinaris, pinto bean Phaseolus vulgaris, sunflower Helianthus annuus) and eight species of perennial grasses (creeping bentgrass Agrostis stolonifera, crested wheatgrass Agropyron cristatum, intermediate wheatgrass Thinopyrum intermedium, tall fescue Schedonorus arundinaceus, Bermuda grass Cynodon dactylon, blue grama Bouteloua gracilis, buffalograss Bouteloua dactyloides, switchgrass Panicum virgatum) to 40 g of scoria road dust every other day for 10 and 14 days, respectively, resulting in cumulative dust exposure of 200 g/m 2 for annual plants and 280 g/m 2 for perennial grasses. Chlorophyll concentration tended to increase in all annual plants within 1–2 h of dust exposure, which remained high (along with photosynthetic yield) over the duration of the study. Stomatal conductance tended to decrease over the 2-week study period, which was expected, while leaf temperature also decreased for most species, which was contrary to previous research. Conversely, we found little evidence that high levels of dust reduce the ability of perennial grasses to recover from repeated defoliation, regardless of photosynthetic pathway or functional group. While perennial grass growth appears unaffected by the heavy dust emissions produced by traffic associated with energy extraction, the effect on annual plants is difficult to determine because dust might actually have a positive, light-scattering effect that improves plant performance. [ABSTRACT FROM AUTHOR]

Copyright of Gesunde Pflanzen is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Eighteen physio-biochemical traits influencing seed vigour were studied for their association with molecular markers using a mini core set constituted from 120 germplasm lines. High genetic variation was detected in the parameters namely chlrophyll a, Chlrophyll b, total chlorophyll, carotenoids, total anthocyanin content, gamma-oryzanols, total phenolics content, superoxide dismutase, catalase, guaicol peroxidase, total soluble sugar, total protein, seed vigour index -I and seed vigour index -II. Strong positive correlation of seed vigour index II was observed with amylose content, total anthocyanin content, catalase, total phenolic content and total flavonoid content while a negative association was observed for gamma-oryzanol content. High gene diversity (0.7169) and informative markers value (0.6789) were estimated from the investigation. Three genetic structure groups were observed in the panel population and genotypes were grouped in the subpopulations based on the seed vigour trait. Differences in the fixation indices of the three sub populations indicated existence of linkage disequilibrium in the studied panel population. Association of the traits namely total flavonoids, superoxide dismutase, catalase, chlorophyll a, Chlorophyll b, total chlorophyll, carotenoids, starch, amylose, total anthocyanin, gamma-oryzanol, total phenolics with the molecular markers were detected by Generalized Linear Model and Mixed Linear Model showing > 0.10 R2 value. Association of the trait, total flavonoids with marker RM7364 located on chromosome 8 reported in earlier study was validated in this investigation. The validated markers and the novel markers detected showing higher R2 value will be useful for improvement of seed vigour in rice. [ABSTRACT FROM AUTHOR]

Bread wheat spring cultivar Saratovskaya 29 (S29) is a highly drought tolerant. S29, five single chromosome substitution and two introgression lines of this cultivar for chromosomes of second homoeological group were grown in a climatic chamber under optimal and water deficit conditions of water supply. The donor of the three homologous chromosomes 2A, 2B and 2D was the German spring cultivar Yanetskis Probat; the donors of chromosome 2D were the old spring varieties of Western Siberia, Caesium 111 and Sibirka 1818. The donors of 2A chromosome were the species Triticum timopheevii and Aegilops markgrafii. Eleven physiological indexes including water use efficiency, the chlorophyll a, chlorophyll b and carotenoids contents, osmotic substances contents, antioxidant enzymes activities and lipoxygenase activity were measured in leaves of wheat at the stage of beginning of earing. To assess genotypes, we established a comprehensive evaluation value (D) based on various measured physiological parameters and shoot biomass. The D positively correlated with the tolerance of shoot biomass (r = 0.955, P < 0.001) and was reduced in four of seven lines with a modified genome. The least stable were the line with the introgression from Aegilops markgrafii in 2A chromosome and the line with the substitution of 2D chromosome of the recipient for the homoeologous chromosome from Sibirka 1818. All lines changed the adaptation strategy compared to the recipient variety. The accumulation of a large amount of soluble sugars in the leaves of lines was the largest difference between them and the recipient S29. [ABSTRACT FROM AUTHOR]

Water deficit is the most limiting factor for seed yield of crop species in the arid and semi-arid regions. Due to increasing limitation of fresh water resources and importance of safflower (Carthamus tinctorius L.) as a significant oilseed crop in Iran, it is necessary to evaluate physiological responses of drought tolerance and its association with seed yield of this crop in water stress condition. In this study, 21 safflower genotypes were planted by hand in the field under water stress and non-stress conditions in a randomized complete block design with two replications during 2 years (2016–17). The results indicated that water deficit stress significantly reduced relative water content (RWC), chlorophyll a (Chl-a) and chlorophyll b (Chl-b) concentrations and seed yield, but increased ascorbate peroxidase (APX) and peroxidase (POX) activities and leaf proline concentration. Significant differences were observed among the genotypes for all studied traits except Chl-b concentration. Genotypes were discriminated according to their response to drought using stress tolerance index (STI). Drought tolerant genotypes displayed a higher capability for accumulation of proline in association with maintaining RWC, antioxidant enzymes activity and higher seed yield, compared to the drought sensitive genotypes. Presented results suggested that safflower genotypes with higher levels of antioxidant enzymes activity, RWC and proline accumulation are characterized by a higher STI. Therefore, these physiological traits can be employed as effective criteria for selecting safflower genotypes with more tolerance to water deficit stress. [ABSTRACT FROM AUTHOR]

Background and aims: Plasticity of plants refers to their ability to produce different phenotypes in different environments. Plants show plasticity aboveground as well as belowground. The influence of the arbuscular mycorrhizal fungal (AMF) symbiosis on root plasticity is poorly known. This study aimed to quantify plasticity of root-system related, morphological, physiological or mycorrhizal traits along a soil phosphorus (P) supply gradient. Methods: Six varieties of maize (Zea mays L.) were grown in pots with or without AMF at five rates of P supply. Fifteen root traits were measured and calculated after seven weeks of growth. Results: Root system traits (biomass and length) and physiological traits (phosphatase activity at the root surface and in the rhizosphere) showed high plasticity along the P gradient, whereas morphological traits (specific root length and root diameter) exhibited low plasticity. Mycorrhizal presence reduced root-system plasticity (biomass and length), increased morphological-trait plasticity (specific root length and proportion of fine roots), but had little effects on other traits. Conclusion: Our results indicate that trait plasticity related to the root system constitutes the most important adaptive strategy for maize to variation in P supply, and that the mycorrhizal symbiosis reduces root-system plasticity. [ABSTRACT FROM AUTHOR]

Drought stress limits the oilseed crops productivity in semi-arid areas. To alleviate drought stress effects during seed-filling stage, the effect of foliar application of different Zn concentration (0, 0.6 and 1.2 kg ha−1) on five safflower genotypes was investigated in a 2-year (2015–2016 and 2016–2017) field experiments. The results showed that supplemental Zn (1.2 kg ha−1) significantly increased drought resistance by enhancement in proline (20%) and carbohydrate accumulation (4.3%), relative water content (2.4%) and chlorophyll content (3.8%) in all studied safflower genotypes. The induced improve in safflower's physiological traits achieved in the Zn supplemented treatment resulted in a significant increase in genotypes yield and its components. Moreover, Zn foliar application significantly reduced the drought adverse effect on oil yield and improved the unsaturated fatty acids content. Finally, Zn foliar application can represent an effective means to mitigate the adverse effects of drought stress on growth and the yield of safflower genotypes in water shortage condition. [ABSTRACT FROM AUTHOR]

Heat stress is one of the abiotic stresses that limit the production and productivity of barley. Understanding the genetic variation, changes in physiological processes and level of genetic diversity existing among genotypes are needed to produce new cultivars not only having a high tolerance to heat stress, but also displaying high yield. To address this challenge, a set of 60 highly homozygous, diverse barley genotypes were evaluated under normal and heat stress conditions in two seasons of 2014/2015 and 2015/2016. Seedling vigor (SV) as a morphological trait was visually scored under normal conditions. Plant height (Ph), days to flowering (DOF), 1000-kernel weight (TKW), grain yield per spike (GYPS), yield per plot (YPP) and biological yield (BY) were measured. Moreover, proline content (ProC), soluble carbohydrate content (SCC), starch content, soluble protein (SP), and amino acid (AA) content as physiological parameters were analyzed from the grains. High genetic variation was observed among genotypes for all traits scored in this study. All traits had high broad-sense heritability estimates ranging from 0.59 (SV) to 0.97 (TKW) for yield traits. Seedling vigor was significantly correlated with all yield traits under both conditions. Among all physiological traits, the increase in ProC and reduction in starch content due to heat stress had significant correlations with the reduction due to heat stress in YPP, GYPS, TKW, and BY. Furthermore, the genetic diversity based on genetic distance (GD) among genotypes was investigated using 206 highly polymorphic SSR marker alleles. The GD ranged from 0.70 to 0.98 indicating that these genotypes are highly and genetically dissimilar. The combination of analyses using molecular markers, genetic variation in yield traits, and changes in physiological traits provided useful information in identifying the tolerant genotypes which can be used to improve heat tolerance in barley through breeding. [ABSTRACT FROM AUTHOR]

Background: Nitrogen is one of the most important mineral nutrients for plants and is absorbed by the root system mainly in the inorganic form (NH + 4 and NO - 3 ). Plants absorb nitrogen as a food source for growth, biomass production, and development. Nitrogen is mainly absorbed as nitrate, which is the most common source of nitrogen available to higher plants. One of the unique features of nitrate transport is that NO - 3 is both a substrate for transport and an inducer of NO - 3 transport systems in genes and at physiological levels., Methods: In the present study, morphological and physiological traits (chlorophyll a/b, total chlorophyll, and carotenoid, antioxidant enzymes, and protein content), correlation between traits and gene expression, and principle component analysis of traits among five barley cultivars were measured in response to nitrogen deficiency (ND). The starved plants were transferred to a nutrient solution containing 0.2 mM and 2 mM NO - 3 up to 7 and 14 days after ND application and non-stressed conditions, respectively., Results: Gene expression analysis revealed that the 10 HvNRT2 genes were induced in the leaf and root tissues at 7 and 14 days after ND treatments in five barley cultivars. Expression of NRT2 genes by relative quantitative qRT-PCR analysis for 10 HvNRT2 genes were determined. Based on the gene expression, HvNRT2.1, HvNRT2.2, and HvNRT2.4 were strongly induced by NO - 3, peaking at 7 and 14 days after ND treatment. In contrast, the HvNRT2.4 showed only moderate induction in both leaves and roots. From our results, the Reyhan cultivar showed a significant increase in root fresh weight (RFW), protein content, and antioxidant enzyme activity in roots at 7 and 14 days after ND treatment as compared to the non-stressed condition. A highly positive correlation was observed between root catalase (CATr) and HvNRT2.2/2.5/2.6 leaves., Conclusion: The expression of HvNRT2.4 is increased during long-term nitrogen starvation, while the expression of HvNRT2.1 and HvNRT2.2 are transiently increased by ND. Based on physiological and morphological traits and molecular mechanisms, the Reyhan is considered a tolerant cultivar under ND condition., (© 2023. The Author(s).)

Intraspecific functional trait variability plays an important role in the response of plants to environmental changes. However, it is still unclear how the variability differs across three nested spatial scales (individual, plot, and site) and which determinants (climatic, soil, and ontogenetic variables) shape the trait variability. Along a latitudinal gradient in Korean pine broadleaved forest of northeast China, we quantified the extent of intraspecific variability of four functional traits in two dominant trees Pinus koraiensis and Fraxinus mandshurica at eight sites, including specific leaf area, leaf dry matter content (morphological traits) and leaf nitrogen content, leaf phosphorus content (physiological traits). Results showed a large trait variation within and between species (coefficient variation: 6.07-23.3%). The leaf physiological traits of F. mandshurica and morphological traits of P. koraiensis were more responsive at site scale, while the morphological traits of F. mandshurica and physiological traits of P. koraiensis were more responsive at individual scale. In addition, abiotic and biotic factors explaining functional trait variation differ markedly between the two tree species, with physiological trait of F. mandshurica being more associated with climate and soil, while traits variability in P. koraiensis was not affected by climate, soil, and ontogeny, except for leaf phosphorus content. Overall, we can predict that the physiological traits of broadleaved species tend to be more sensitive to environmental changes, while pines are more sensitive to competition. It is critical to determine which spatial scale and trait type should be taken into account in predictive models of vegetation dynamics. [ABSTRACT FROM AUTHOR]

Physiological breeding complementing the conventional approach is increasingly being explored in wheat in view of stagnating annual genetic yield gain. Designing improved plant types required knowledge about physiological traits associated with yield gain in the past. Fourteen wheat varieties including 12 historically important and popular (mega) wheat cultivars and two recently registered varieties were observed for various physiological traits for two years. Both breeding period and genotypes within breeding period accounted for significant differences for most of the physiological traits. Regression analysis indicated curvilinear trend for leaf area index (LAI), flag leaf area, and root length and root weight. Near perfect leaf area index (LAI 5.94) with semi-erect leaves and higher flag leaf area was observed in all time mega variety HD 2967 indicated the importance of plant architecture and crop canopy in yield maximization. Linear declining trend was observed for coleoptile length, number of stomata per cm2 and flag leaf length. Increasing trend for total chlorophyll content and normalized difference for vegetative indices (NDVI) at both vegetative and flowering stage indicated the importance of leaf greenness in yield improvement. Root length has continuously declined except for the latest released varieties, however no such trend was observed for root weight. We propose that grain yield stabilization at still higher level can be achieved by increasing photosynthetic capacity, optimizing the crop canopy slightly less than the optimum, and better partitioning to grain yield through directed physiological based breeding. [ABSTRACT FROM AUTHOR]

Increase in maize grain yield in West Africa can be achieved by developing maize varieties tolerant to low soil nitrogen (N) and improving soil fertility. Six maize populations were evaluated in two locations in Nigeria under low-N (45 kg N ha-1 ) and high-N (90 kg N ha-1 ) conditions to identify morphological and physiological traits that changed in genotypes that had undergone recurrent selection for tolerance to low soil N and to determine the relationship between physiological and yield traits in both nitrogen environments. Results revealed that improved cycles of three populations displayed longer leaf area duration, larger leaf area ratio, larger leaf area index and higher crop growth rate (CGR) at silking than their earlier versions at 45 and 90 kg N ha-1. Net assimilation rate increased significantly in response to selection in three out of six populations at 45 kg N ha-1. Significant yield changes were observed in response to selection in three populations at 45 kg N ha-1 and four populations at 90 kg N ha-1, accompanied by increments in 100 kernel weight in three populations and number of kernels per row in one population. Grain yield and 100 kernel weight reduced by 31 and 5% respectively in response to N-stress. Among physiological traits, only CGR and SPAD chlorophyll readings had significant positive relationship with grain yield under low and high N conditions. Hence, CGR and SPAD chlorophyll values can be utilized in selecting for tolerance to low-N in maize for West Africa region. [ABSTRACT FROM AUTHOR]

Salinity is one of the major abiotic stresses that severely effects rice production throughout the world. Previously, there have not been many studies which focused on studying diversity among rice germplasm based on specific physiological traits for salt tolerance. Our diversity study was based on physiological traits such as Na+ concentration, K concentration, K/Na ratio, osmotic potential, and biomass which are major components determining salt tolerance. This study has systematically analyzed phenotypic data of 191 germplasms in two different salt concentrations apart from the control. The current study identified salt tolerant germplasms based on their response to a single physiological trait as well as a combination of different physiological traits. Some of the germplasm identified outperformed known salt tolerant cultivar Pokkali. This study identifies correlation among various physiological traits. The salt tolerant germplasms can be taken forward into developing better varieties by conventional breeding and exploring genes for salt tolerance. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the impact of thermal stress on milk production and physiological traits of Baladi goats under subtropical Egyptian conditions. Sixty dairy Baladi goats were exposed to three different levels of temperature-humidity index (THI), including low (less than 70), moderate (over 70 and up to 80), and high levels (over 80). The influence of THI on the milk composition and physiological, hematological, and biochemical traits was investigated. Rectal temperature and respiration rate were significantly greater at the higher THI than at low and moderate THI ( p = 0.016 and 0.002, respectively). Baladi goats had decreased daily milk yield in a rate of 27.3 and 19.3 % at high THI level, compared with low and moderate THI, respectively ( p = 0.031). On the contrary, no significant differences have been reported in protein, fat, and total solids percentages at different THI levels. Total leucocyte count, serum glucose, and total protein were significantly reduced at high THI in comparison with low and moderate THI levels ( p = 0.043, 0.001, and 0.001, respectively). However, dairy goats maintained relatively stable estimates for erythrocytes count, hemoglobin, serum triglycerides, cholesterol, catalase, total antioxidant capacity, and triiodothyronine at different THI levels. Our results indicate that dairy Baladi goats can tolerate THI levels up to 80; however, variable reduction in milk yield and few biochemical (serum total protein and glucose) and hematological (leucocytes count) parameters have been reported at a THI level higher than 80. [ABSTRACT FROM AUTHOR]

Soil waterlogging is a primary constraint to crop yield both globally and in the United States, yet little is known about the genetic control of waterlogging tolerance in wheat. The objective of this study was to characterize genetic variation for key adaptive traits influencing waterlogging tolerance at the vegetative stage and to identify associated quantitative trait loci (QTL). Traits measured included shoot and root biomass, root length, tiller number, seedling height, stem elongation, and chlorophyll content. Waterlogging reduced traits means by 8-58 % in the greenhouse and by 22-32 % in the field, with the largest reduction observed for root length. Both root biomass and root length showed significant genotype by treatment interaction indicating an adaptive growth response in waterlogged versus non-waterlogged soils and a possible mechanism of tolerance. A positive correlation was observed between chlorophyll content and shoot biomass, and between root and shoot biomass under waterlogging, which may make indirect selection possible. QTL analysis identified 48 individual QTL that clustered into 10 genomic regions consistently detected in both the greenhouse and field experiments. While most clusters were constitutively expressed, regions on chromosomes 1B and 6D were found to be adaptive to conditions of soil waterlogging, with no QTL detected in the non-waterlogged controls. A QTL region on chromosome 1D specific for chlorophyll content was significant across environments and repeated measurements, explaining up to 24 % of the phenotypic variation. This study provides the first reported QTL for waterlogging tolerance in wheat identified under both field and greenhouse conditions. The QTL can be targeted by breeders for future genetic improvement. [ABSTRACT FROM AUTHOR]

Cadmium (Cd) is one of the most toxic pollutants that caused severe threats to animal and human health. Bermudagrass is a dominant species in Cd contaminated soils, which can prevent Cd flow and spread. The objectives of this study were to determine the genetic variations in major physiological traits related to Cd tolerance in six populations of Bermudagrass collected from China, and to examine the genetic diversity and relationships among these accessions that vary in Cd tolerance using molecular markers. Plants of 120 accessions (116 natural accessions and 4 commercial cultivars) were exposed to 0 (i.e. control) or 1.5 mM CdSO·8/3HO for 3 weeks in hydroponic culture. Turf quality, transpiration rate, chlorophyll content, leaf water content and growth rate showed wide phenotypic variation. The membership function method was used to comprehensively evaluate Cd-tolerance. According to the average subordinate function value, four accessions were classified as the most tolerant genotypes and four accessions as Cd-sensitive genotypes. The trend of Cd tolerance among the six studied populations was as follows: Hunan > South China > North China > Central China > West South China and Xinjiang population. Phylogenetic analysis revealed that the majority of accessions from the same or adjacent regions were clustered into the same groups or subgroups, and the accessions with similar cadmium tolerance displayed a close phylogenetic relationship. Screening genetically diverse germplasm by combining the physiological traits and molecular markers could prove useful in developing Cd-tolerant Bermudagrass for the remediation of mill tailings and heavy metal polluted soils. [ABSTRACT FROM AUTHOR]

Key message: The genotype 'Neva' under high plant density showed the highest biomass yield and optimal physiological strategies and could be the most suitable choice under semi-arid environment Abstract: The poplars ( Populus spp.) are the most sensitive plants to water deficit conditions among the woody species utilized for biomass production for energetic purposes; their productivity is associated with water availability in the soil. In the Mediterranean environment, crops are mainly limited by evapotranspirative demand that is not balanced by rainfall supply. As new hybrids with high growth rates and resistance to water stress are selected, the use of poplar as an energy crop may increase in Southern regions of Mediterranean Europe. The growth dynamics and physiological characteristics of poplar hybrid genotypes have been monitored for 2 years at a site with a Mediterranean climate, Apulia region, that could be used for energy crops. Unrooted cuttings of three recently selected genotypes of poplar ('Neva', 'Dvina' and 'Lena') and two 'traditional' genotypes ('Luisa Avanzo' and 'Bellini') were planted in the spring of 2010 at two different densities: (a) low plant density = 1,667 cuttings ha (LPD); (b) high plant density = 6,667 cuttings ha (HPD). The genotypes 'Lena' and 'Dvina' showed the lowest survival rates and the poorest growth among the hybrid poplar tested. The genotype 'Bellini' had low stomatal sensitivity to soil water content and a moderate productive performance. The genotypes 'Luisa Avanzo' and 'Neva' had a good degree of rooting and sprouting, high values of leaf relative water content (RWC) and low values of stomatal conductance ( g) during the summer months. In 'Neva', these characteristics were associated with the best yields (4 t ha) in HPD. [ABSTRACT FROM AUTHOR]

Migration distance is supposed to represent an important selection pressure shaping physiological and morphological properties. Previous work has focussed on this effect, while the importance of ecological barriers in this context has been rarely considered. We studied two subspecies of a migratory songbird, the northern wheatear ( Oenanthe oenanthe oenanthe and O. o. leucorhoa L.), on an island in the North Sea. The former subspecies reaches their Scandinavian breeding areas after a short sea crossing, whereas leucorhoa northern wheatears cross the North Atlantic towards Iceland, Greenland or Canada. Physiological traits (fuel deposition rate) and wings' aerodynamic properties (wing pointedness independent of body size), both affecting migration speed, were hypothesized to be more pronounced in leucorhoa than in oenanthe northern wheatears. Within subspecies, the physiological and aerodynamic properties were hypothesized to explain arrival date at the stopover site with 'fast migrants' arriving early. Physiological and aerodynamic properties in leucorhoa northern wheatears lead to a faster and less costly migration, favouring a sea crossing, but in trade-off lower flight manoeuvrability than in oenanthe birds. Wings' aerodynamic properties affected the seasonal occurrence of leucorhoa females, whereas the physiological traits significantly influenced arrival date in oenanthe individuals. The less risky migration route in oenanthe birds with few short sea crossings may have favoured higher flight manoeuvrability for foraging (less pointed wings), in trade-off an energetically more costly flight. Hence, not the migration distance itself, but the presence/absence of a sea barrier presents an important selection pressure in migratory land birds favouring low flight costs. [ABSTRACT FROM AUTHOR]

The paper evaluated the effects of Se application time and rate on physiological traits, grain Se content, and yield of winter wheat by field experiment. Se application significantly increased grain Se content and yield, and the increased amount treated with 20 and 30 mg Se L was the highest. At blooming-filling stage, Se application significantly increased grain Se content, but did not affect yield. Chlorophyll content was increased by Se application, and the increased amount at heading-blooming stage was higher than that in wheat leaves at the other stages. At four development stages, Se treatments (except for 10 mg Se L at jointing-heading stage) significantly decreased the rate of superoxide (O) radical production. At heading-blooming (except for 50 mg Se L) and blooming-filling stages, hydrogen peroxide (HO) content was significantly decreased by Se treatments. The rate of O production and HO content at 20 and 30 mg Se L was the lowest. Se treatments (except for 10 mg Se L at regreening-jointing and blooming-filling stages) also induced an evident decrease in malondialdehyde content. Proline content induced by Se treatments at jointing-heading and heading-blooming stages was higher than that in wheat leaves at regreening-jointing and blooming-filling stages. At four development stages, Se treatments all significantly increased glutathione peroxidase activity, and the treatments with 20 and 30 mg Se L also evidently increased reduced glutathione content. These results suggested that Se application at different development stages increased antioxidant capacity of wheat, reduced oxidant stress to some extent, and the effects of Se treatments was the best if Se concentration ranged between 20 and 30 mg Se L. In addition, Se application time was more beneficial for Se accumulation and yield in wheat grain at heading-blooming stage. [ABSTRACT FROM AUTHOR]

Forest restoration programs using Holm oak ( Quercus ilex ssp. ballota [Desf.] Samp.) have had limited success. The effect of plant provenance on plantation success is uncertain, although some previous studies suggest that some provenances may be better able to tolerate stress. We studied the tolerance to drought in seedlings from two Spanish provenances of Holm oak before and after outplanting. One provenance was from a continental climate with cold winters ( GR) and the other was from a xeric climate ( HU). Seedlings were subjected to a water stress test in the nursery during the summer and survival was visually assessed after 2 weeks. In addition, 35 healthy seedlings of each provenance that were not subjected to the water stress tests were used for outplanting experiment. In these plants the seasonal changes in water potential at dawn (Ψ), specific leaf area (SLA), cuticular transpiration (E), and loss of xylem hydraulic conductance of twigs (PLC) were measured over 18 months. After the water stress test in summer, mortality was 44.3 % for GR seedlings and 12.6 % for HU seedlings. In addition there were differences between the two provenances in plant water status after planting. The HU provenance had a better water status and was more water conservative in the summer (higher Ψ, lower E, lower PLC), but not in the winter. The different drought tolerance and water relations parameters of these two provenances indicate that provenance should be considered in forest restoration and conservation programs involving Holm oak. [ABSTRACT FROM AUTHOR]

Twenty genotypes of Jatropha collected from diverse eco-geographic regions from the states of Chhattisgarh (3), Andhra Pradesh (12), Rajasthan (4) and Uttarakhand (1) of India were subjected to elevated CO conditions. All the genotypes showed significant difference ( p < 0.05 and 0.01) in the phenotypic traits in both the environments (elevated and ambient) and genotype x environment interaction. Among the physiological traits recorded, maximum photosynthetic rate was observed in IC565048 (48.8 μmol m s) under ambient controlled conditions while under elevated conditions maximum photosynthetic rate was observed in IC544678 (41.3 μmol m s), and there was no significant difference in the genotype x environment interaction. Stomatal conductance (Gs) emerged as the key factor as it recorded significant difference among the genotypes, between the environments and also genotype x environment interaction. The Gs and transpiration (E) recorded a significant decline in the genotypes under the elevated CO condition over the ambient control. Under elevated CO conditions, the minimum values recorded for Gs and E were 0.03 mmol m s and 0.59 mmol m s respectively in accession IC565039, while the maximum values for Gs and E were 1.8 mmol m s and 11.5 mmol m s as recorded in accession IC544678. The study resulted in the identification of potential climate ready genotypes viz. IC471314, IC544654, IC541634, IC544313, and IC471333 for future use. [ABSTRACT FROM AUTHOR]

We investigated phenotypic variation of Populus simonii from five provenances in northern China. Our results show that significant differences exist between plants of different provenances in morphological and physiological traits, except for leaf-stalk length and the number of leaf margins. The coefficient of variation for all traits ranges from 14.77% to 81.49%. The mean phenotypic coefficient of differentiation ( V) is 47.1%, which means that the variation within provenances is the major source for phenotypic variation in P. simonii. Given our cluster analysis of provenances based on an average linkage computing method, the five provenances of P. simonii investigated could be divided into three groups. Our results provide a theoretical basis for genetic resource conservation and provenance selection of natural P. simonii in northern China. [ABSTRACT FROM AUTHOR]

Spot blotch, caused by Cochliobolus sativus (Ito and Kurib.) Drechsler ex Dastur, and heat stress are two important stresses of bread wheat ( Triticum aestivum L.) causing substantial yield reduction in the warm areas of South Asia. These two stresses put pressure on at least 25 million hectares of wheat areas worldwide. This study was conducted to examine variation in physiological traits and its association with heat and spot blotch. Eleven diverse bread wheat genotypes were evaluated in replicated field trials under spot blotch epidemics and heat stress conditions in 2006 and 2007 at Rampur, Nepal. Canopy temperature depression (CTD), chlorophyll fluorescence (CF), chlorophyll content, percent disease leaf area, yield and yield components were recorded. Heat and spot blotch individually reduced CTD, CF, chlorophyll content, grain yield (GRY), and thousand kernel weight (TKW), with greater reductions recorded under combined stress. Genotypes showing lower GRY or TKW loss due to spot blotch also exhibited lower yield loss due to heat stress or combined heat and disease stress, suggesting an association between tolerance mechanisms to the stresses. The physiological traits chlorophyll content, CF and CTD showed higher correlations with GRY and TKW than with area under disease progress curve (AUDPC) suggesting their potential application in screening for heat and spot blotch tolerant genotypes. Genotypes with lower disease showed the highest values for chlorophyll content, CF and CTD. Our findings provide new information on the relationship of these physiological traits with spot blotch resistance and heat tolerance when examined in the same study. The physiological traits studied have potential application in integrative indirect selection criteria for improving spot botch and heat tolerance in wheat. [ABSTRACT FROM AUTHOR]

This paper aims to discover the genetic parameters underlying the physiological efficiency and panicle characters of hill rice plants. In order to improve these characters, it is crucial to learn the nature and magnitude of gene action involved in inheritance of panicle and physiological traits. With this purpose, we combined a line × tester analysis of crosses involving local cultivars and indigenous and exotic germplasm grown at the northeastern hill region of India. From the study it follows that number of tillers per hill, number of ear bearing tillers per hill, panicle length, panicle weight, number of grains per panicle, number of filled grains per panicle, pollen fertility, spikelet fertility, leaf area index, total chlorophyll content and harvest index were mainly under the control of non-additive gene action, while total dry matter accumulation and grain yield per plant were under the control of additive gene action. The genotypes DR 92, Ngoba, IET 16451 and UPR 1425-1-1-4 were identified as superior parents with high performance and significant general combining ability effects. For heterosis breeding six cross combinations, viz., DR 92/IET 16471, DR 92/UPR 1425-1-1-4, DR 92/IET 15482, Ngoba/IET 16469, Ngoba/H274-27-24, Manipuri/IET 16451, and for recombination breeding two cross combinations, viz., DR 92/IET 16470 and Ngoba/UPR 1425- 1-1-4, were found suitable to ameliorate the panicle and physiological traits of hill rice grown in northeastern India. [ABSTRACT FROM AUTHOR]