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Plant strategies for nutrient acquisition and recycling are key components of ecosystem functioning. How the evolution of such strategies modifies ecosystem functioning and services is still not well understood. In the present work, we aim at understanding how the evolution of different phenotypic traits link aboveground and belowground processes, thereby affecting the functioning of the ecosystem at different scales and in different realms. Using a simple model, we follow the dynamics of a limiting nutrient inside an ecosystem. Considering trade-offs between aboveground and belowground functional traits, we study the effects of the evolution of such strategies on ecosystem properties (amount of mineral nutrient, total plant biomass, dead organic matter, and primary productivity) and whether such properties are maximized. Our results show that when evolution leads to a stable outcome, it minimizes the quantity of nutrient available (following Tilman's R* rule). We also show that considering the evolution of aboveground and belowground functional traits simultaneously, total plant biomass and primary productivity are not necessarily maximized through evolution. The coupling of aboveground and belowground processes through evolution may largely diminish predicted standing biomass and productivity (extinction may even occur) and impact the evolutionary resilience (i.e., the return time to previous phenotypic states) of the ecosystem in the face of external disturbances. We show that changes in plant biomass and their effects on evolutionary change can be understood by accounting for the links between nutrient uptake and mineralization, and for indirect effects of nutrient uptake on the amount of detritus in the system. [ABSTRACT FROM AUTHOR]

Invasive species benefit from advantageous trait values and/or trait plasticity in their invasion process when facing changing environments. However, few studies explored this mechanism on invasive macrophytes. The effects of soil on the invasion of macrophytes were studied little by previous researches. In the measurement of several traits related to resource utilization, we studied the plant responses to three representative types of riparian soil in Liangzi Lake, China. Using multi-species comparison, we explored the differences of trait values and trait plasticity among Eichhornia crassipes (Mart.) Solms and its non-invasive confamilial counterparts all in emergent life-form-exotic Pontederia cordata L. and native Monochoria vaginalis (Burm. f.) Presl ex Kunth. We measured leaf-level and root-level traits after harvest. We found that E. crassipes mainly showed trait value advantages in root-level traits in infertile soils, while some advantages of leaf-level traits were present but not obvious compared to the two confamilials. Besides, E. crassipes showed higher plasticity in several traits especially in some root-level traits than the two confamilials. We concluded that both trait values and trait plasticity especially in belowground traits play a crucial role in the invasion success of emergent E. crassipes. [ABSTRACT FROM AUTHOR]

Time series have played a critical role in documenting how phenology responds to climate change. However, regressing phenological responses against climatic predictors involves the risk of finding potentially spurious climate-phenology relationships simply because both variables also change across years. Detrending by year is a way to address this issue. Additionally, detrending isolates interannual variation in phenology and climate, so that detrended climate-phenology relationships can represent statistical evidence of phenotypic plasticity. Using two flowering phenology time series from Colorado, USA and Greenland, we detrend flowering date and two climate predictors known to be important in these ecosystems: temperature and snowmelt date. In Colorado, all climate-phenology relationships persist after detrending. In Greenland, 75% of the temperature-phenology relationships disappear after detrending (three of four species). At both sites, the relationships that persist after detrending suggest that plasticity is a major component of sensitivity of flowering phenology to climate. Finally, simulations that created different strengths of correlations among year, climate, and phenology provide broader support for our two empirical case studies. This study highlights the utility of detrending to determine whether phenology is related to a climate variable in observational data sets. Applying this as a best practice will increase our understanding of phenological responses to climatic variation and change. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing 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.)

Recognizing both the stakes of traditional European common bean diversity and the role farmers' and gardeners' networks play in maintaining this diversity, the present study examines the role that local adaptation plays for the management of common bean diversity in situ. To the purpose, four historical bean varieties and one modern control were multiplied on two organic farms for three growing seasons. The fifteen resulting populations, the initial ones and two populations of each variety obtained after the three years of multiplication, were then grown in a common garden. Twenty-two Simple Sequence Repeat (SSR) markers and 13 phenotypic traits were assessed. In total, 68.2% of tested markers were polymorphic and a total of 66 different alleles were identified. FST analysis showed that the genetic composition of two varieties multiplied in different environments changed. At the phenotypic level, differences were observed in flowering date and leaf length. Results indicate that three years of multiplication suffice for local adaptation to occur. The spatial dynamics of genetic and phenotypic bean diversity imply that the maintenance of diversity should be considered at the scale of the network, rather than individual farms and gardens. The microevolution of bean populations within networks of gardens and farms emerges as a research perspective. [ABSTRACT FROM AUTHOR]

Phenotypic plasticity is the phenomenon that one particular genotype produces different phenotypes under different environmental conditions, but its underlying molecular and genetic mechanisms are poorly understood. Plastic traits may be under the control of genes whose expression is modulated by environmental cues. In this study, we investigated phenotypic plasticity in tomato (Solanum lycopersicum) and its ancestral species S. pimpinellifolium by comparing the global gene expression of young seedlings grown under two distinct growth conditions. Our results show that more than 7000 genes exhibited differential expression in response to environmental changes from phytotron to a plastic greenhouse, and 98 environmentally sensitive genes displayed the same patterns of expression response across the two tomato species. We also found that growth conditions had a remarkable impact on transcriptome complexity, attributable to alternative splicing (AS), in which 665 splice variants showed differential expression in response to the environmental changes. Moreover, more splice variants and AS events per gene were detected in plastic greenhouse-grown seedlings than their phytotron counterparts, and these seedlings also had higher percentages of intron retention events. The identification of the conserved environmentally-sensitive genes and the splice variants in this study will be useful for further analysis of gene regulation of environmental response in tomato and other crops. [ABSTRACT FROM AUTHOR]

Although exceptional heterosis for yield in the world's first commercial single cross maize ( Zea mays L.) hybrid SR52 has been confirmed, the role of secondary traits hasn't been established. Objectives of this study were to establish relationship between grain yield and secondary traits, while assessing heritability and genotypic variation in SR52's segregating populations. Knowledge on associations between yield and secondary traits would be crucial in extracting productive inbred lines from the population. Traits were subjected to correlation and path-coefficient analyses. Path analysis model accounted for over 70% of variation (R) in all populations. Consistently high positive correlations with grain yield were observed for ear length and number of kernel rows on ear. Ear girth (0.19), and number of kernels per row (0.48) showed high direct effects on yield in the F population and the trend was consistent in the backcrosses. Positive indirect effects of most traits on grain yield were negligible with the exception of kernel per row via total number of kernels on ear, which was above 0.40 in the F and BCP1. Ear length can be exploited for indirect selection for yield in SR52's segregating generations. 100-kernel weight and number of kernel rows on ear can, to a lesser extent, be targeted in selecting for grain yield. High to medium phenotypic variability in segregating generations of SR52 for traits such as ear length, number kernel rows on ear and grain yield should give impetus to selection of productive inbred lines from SR52 hybrid because of presence of diversity in the gene pool. [ABSTRACT FROM AUTHOR]

Aim Phenotypic plasticity is hypothesized to contribute to a species' capacity to occupy broader ranges of conditions and to optimally exploit resource-rich environments. Although this is supported by case studies of individual species, we do not know whether larger plasticity in functional traits is generally associated with ecological characteristics of species such as their niche breadth or niche position. Here, we test whether there is such a relationship for plasticity in leaf functional traits. Location Central Europe. Methods We surveyed 110-132 grassland plant species for plasticity in five leaf traits [leaf thickness, leaf greenness, specific leaf area, leaf dry matter content ( LDMC) and plant height] and for biomass changes in response to experimental fertilization, shading and waterlogging. Trait plasticity and changes in biomass were compared with species niche characteristics along three environmental axes (light, nutrient and soil moisture) derived from a vegetation-plot database. Results Although response of several traits to experimental treatments correlated with niche position and breadth (change in leaf thickness, greenness and biomass in response to fertilization; change in LDMC due to shading; and change in plant height and biomass due to waterlogging), we did not find evidence that species with broader niches or species from resource-rich environments are more plastic. Ecological generalists even turned out to be less plastic in some traits, including leaf thickness after fertilization and waterlogging. Generalists also displayed smaller plastic response averaged across all five traits ('composite plasticity'), though the relationship was not statistically significant. This composite plasticity was positively related to absolute change in biomass in all experimental treatments. Main conclusions Our results suggest that larger species-level plasticity in leaf traits is not necessarily associated with a capacity to occupy a broader range of environments or with growth in resource-rich habitats; rather, it may indicate species' sensitivity to environmental changes. [ABSTRACT FROM AUTHOR]

The juxtaposition of plant-species invasions with latitudinal gradients in herbivore pressure is an important yet mostly unexplored issue in invasion biology. Latitudinal clines in defense and palatability to herbivores are expected to exist in native plant species but the evolution of these clines may lag behind for invasive plant species resulting in non-parallel latitudinal clines that may impact invasion success. Our study focused on a native and European invasive lineages of the common reed Phragmites australis in North America. Using native and invasive genotypes of P. australis collected across a 17° latitudinal range, we performed experiments in replicate northern and southern common gardens to investigate whether these two lineages exhibited different genetically based latitudinal clines in defenses, nutritional condition, and palatability to their herbivores, the aphid Hyalopterus pruni and the fall armyworm Spodoptera frugiperda. We also tested whether invasive genotypes are more phenotypically plastic than native genotypes and whether plasticity varies with latitude. Although invasive genotypes did not exhibit higher defense levels (leaf toughness, phenolics, percent carbon), they were considerably less palatable to their herbivores than native genotypes. Genetically based latitudinal clines were evident for both native and invasive P. australis and for all defenses, nutrients, and at least one palatability trait for each herbivore. In 36% of the cases where clines were evident, they were non-parallel between the two lineages. These data suggest that clines in the invasive genotypes of P. australis evolved within the past ~100 years. Moreover, our study showed that the occurrence and direction of latitudinal clines in plant traits were commonly dependent on where the study was conducted (north or south), indicating strong phenotypic plasticity in these genetic-based clines. Finally, traits for invasive genotypes of P. australis were 2.5 times more plastic than traits for native genotypes. Interestingly, plasticity for native but not invasive genotypes was strongly dependent on latitude of origin. Such spatial heterogeneity within and between the native and invasive lineages of P. australis with respect to their interactions with herbivores can generate substantial spatial variability in biotic resistance that can have important implications for the establishment and spread of invasive genotypes and species. [ABSTRACT FROM AUTHOR]

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering 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.)

Pinus pinea is characterized by phenotypic plasticity, tolerance to harsh soils and climates, but low differentiation in growth parameters and low genetic variability. Growth and cone production of six European stone pine provenances (two from Italy, three from Spain and one from Slovenia) were analyzed in a field trial experiment established in central Chile. The study evaluated height, diameter at breast height (DBH) and crown diameter growth of 147 nineteen-year-old trees per provenance, as well as fruiting variables (i.e., number of cones per tree and cone weight). Survival over the first 7 years was also evaluated. Provenances significantly differed in cone number per tree, cone weight, height and DBH growth, and crown diameter growth. Provenances were grouped according to growth and production variables: one group included the Italian and Slovenian provenances, the second group Andalucía and Sierra Morena (Spain), and the third included Meseta Castellana (Spain). Individual cone production was positively correlated with cone weight and other growth variables. Meseta Castellana provenance showed the highest growth and productivity. Our results provide useful information for the selection of P. pinea provenances to be used in new plantations in central Chile. [ABSTRACT FROM AUTHOR]

Lognormal distributions and self-similarity are characteristics associated with a wide range of biological systems. The sequential breakage model has established a link between lognormal distributions and self-similarity and has been used to explain species abundance distributions. To date, however, there has been no similar evidence in studies of multicellular organismal forms. We tested the hypotheses that the distribution of the lengths of terminal stems of Japanese elm trees (Ulmus davidiana), the end products of a self-similar branching process, approaches a lognormal distribution. We measured the length of the stem segments of three elm branches and obtained the following results: (i) each occurrence of branching caused variations or errors in the lengths of the child stems relative to their parent stems; (ii) the branches showed statistical self-similarity; the observed error distributions were similar at all scales within each branch and (iii) the multiplicative effect of these errors generated variations of the lengths of terminal twigs that were well approximated by a lognormal distribution, although some statistically significant deviations from strict lognormality were observed for one branch. Our results provide the first empirical evidence that statistical self-similarity of an organismal form generates a lognormal distribution of organ sizes. [ABSTRACT FROM AUTHOR]

To evaluate the population variation, individual plasticity, and local adaptability of Solidago canadensis in response to shade treatment, we conducted a common pots experiment with a total of 150 ramets (5 genets, 15 populations, and 2 treatments) subjected to both control (natural light) and shady treatment (10% of natural light). Shade treatment significantly reduced growth and content of defense metabolites in S. canadensis. Compared to control, shading led to increased height, decreased basal diameter, increased leaf width, increased leaf length, increased chlorophyll content, stronger photosynthetic rate (Pn), stronger stomatal conductance (gs), and lower root to shoot ratio. Three-way analysis of variance revealed geographical origin to significantly affect the basal diameter of S. canadensis, while genotype significantly affected plant height, intercelluar CO2 concentration (Ci), transpiration rate (Tr), and proline content. Significant interactive effects between shade and geographic origin were prevalent for most traits. The phenotypic differentiation coefficient of the plasticity of all traits was below 0.4, indicating that most of all variations can be found among individuals within populations. Phenotypic selection analysis revealed that fitness was significantly positively related to plant height, basal diameter, Ci, total flavonoid content, as well as the plasticity of plant height, leaf length, leaf width, gs, Ci, total flavonoid content, and malondialdehyde content under the control condition. However, subjected to shade, fitness was only significantly positively related to plant height, basal diameter, and the plasticity of basal diameter. Rather than local adaption, these results suggest that individual plasticity played a more prominent role in the shade response of the invasive S. canadensis. [ABSTRACT FROM AUTHOR]

Halophila stipulacea is a small tropical seagrass species. It is the dominant seagrass species in the Gulf of Aqaba (GoA; northern Red Sea), where it grows in both shallow and deep environments (1-50 m depth). Native to the Red Sea, Persian Gulf, and Indian Ocean, this species has invaded the Mediterranean and has recently established itself in the Caribbean Sea. Due to its invasive nature, there is growing interest to understand this species' capacity to adapt to new conditions, which might be attributed to its ability to thrive in a broad range of ecological niches. In this study, a multidisciplinary approach was used to depict variations in morphology, biochemistry (pigment and phenol content) and epiphytic bacterial communities along a depth gradient (4-28 m) in the GoA. Along this gradient, H. stipulacea increased leaf area and pigment contents (Chlorophyll a and b, total Carotenoids), while total phenol contents were mostly uniform. H. stipulacea displayed a well conserved core bacteriome, as assessed by 454-pyrosequencing of 16S rRNA gene reads amplified from metagenomic DNA. The core bacteriome aboveground (leaves) and belowground (roots and rhizomes), was composed of more than 100 Operational Taxonomic Units (OTUs) representing 63 and 52% of the total community in each plant compartment, respectively, with a high incidence of the classes Alphaproteobacteria, Gammaproteobacteria, and Deltaproteobacteria across all depths. Above and belowground communities were different and showed higher within-depth variability at the intermediate depths (9 and 18 m) than at the edges. Plant parts showed a clear influence in shaping the communities while depth showed a greater influence on the belowground communities. Overall, results highlighted a different ecological status of H. stipulacea at the edges of the gradient (4-28 m), where plants showed not only marked differences in morphology and biochemistry, but also the most distinct associated bacterial consortium. We demonstrated the pivotal role of morphology, biochemistry (pigment and phenol content), and epiphytic bacterial communities in helping plants to cope with environmental and ecological variations. The plant/holobiont capability to persist and adapt to environmental changes probably has an important role in its ecological resilience and invasiveness. [ABSTRACT FROM AUTHOR]

Vascular bundles within maize (Zea mays L.) stalks play a key role in the mechanical support of plant architecture as well as in water and nutrient transportation. Convenient and accurate phenotyping of vascular bundles may help phenotypic identification of germplasm resources for breeding. Based on practical sample preparation procedures for maize stalks, weacquired serials of cross-sectional images using a micro-computed tomography (CT) imaging device. An image processing pipeline dedicated to the phenotyping of vascular bundles was also developed to automatically segment and validate vascular bundles from the cross-sectional images of maize stalks, from which phenotypic traits of vascular bundles, i.e. number, area, and spatial distribution, were calculated. More profound quantification of spatial distribution was given as area ratio of vascular bundles, which described the distribution of vascular bundles associated with the centroid of maize stalks. In addition, three-dimensional visualisation was performed to reveal the spatial configuration and distribution of vascular bundles. The proposed method significantly improves computation accuracy for the phenotypic traits of vascular bundles compared with previous methods, and is expected to be useful for illustrating relationships between phenotypic traits of vascular bundles and their function. [ABSTRACT FROM AUTHOR]

Invasive populations often shift phenotypically during introduction. Moreover, they are postulated to show an increased phenotypic plasticity compared with their native counterparts, which could be advantageous. However, less is known about trait selection across populations along the invasion gradient in response to environmental factors, such as increasing drought caused by climate change. In this study, we investigated the impacts of drought on growth, regrowth, and various leaf traits in plants of different origin. Therefore, seeds of 18 populations of the perennial Tanacetum vulgare were collected along the invasion gradient (North America, invasive; West Europe, archaeophyte; East Europe, native) and grown in competition with the grass Poa pratensis under control or dry conditions in a common garden. Above-ground biomass was cut once and the regrowth was measured as an indicator for tolerance over a second growth period. Initially, drought had little effects on growth of T. vulgare, but after cutting, plants grew more vigorously. Against expectations, phenotypic plasticity was not higher in invasive populations, but even reduced in one trait, which may be attributable to ecological constraints imposed by multiple stress conditions. Trait responses reflected the range expansion and invasion gradient and were influenced by the latitudinal origin of populations. Populations of invaded ranges may be subject to faster and more extensive genetic mixing or had less time to undergo and reflect selective processes. [ABSTRACT FROM AUTHOR]

Physiological adaptation may considerably improve aquatic organism survival when subjected to environmental threats in a variable environment. To clarify the metabolic plasticity of the freshwater copepod Eodiaptomus japonicus from Lake Biwa (Japan), respiration rates (R) of the copepod were determined over a temperature range of 8-30°C after acclimatizations at 15 and 25°C using an optical oxygen meter. R increased exponentially from 8 to 28°C and deviated from the exponential phase at 30°C for both acclimatizations with no significant differences, indicating the same metabolic plasticity to changing temperature as occurred in situ. Furthermore, R for copepodites was always high at high temperature, regardless of body weight. Therefore, it is possible to evaluate the metabolic costs of wild populations using the respiration rate temperature equation formulated in this study. Net growth efficiencies (K2) calculated from respiration losses in this study and growth rates in a previous study of food effects showed low K2 in the food-limited animals at high temperature, implying that high metabolic costs at higher temperatures induce decreasing growth rates in food-limited environments. Hence, the E. japonicus population that suffers from food shortage in Lake Biwa is probably threatened by temperature increase due to global warming. [ABSTRACT FROM AUTHOR]

Bassia belongs to the family Chenopodiaceae, which is widely distributed in the world, especially in Irano-Turanian Region. According to the morphological similarities among the species of the genus, ecological implications of structural features were studied. In fact, understanding these relationships is of great importance in natural classification. We have studied the relationships of Bassia species using morphological, anatomical, and micro-morphological methods. The current results indicated that phenotypic plasticity and repetitive patterns were probably due to ecological adaptations, especially in decreasing the leaf surface by changing the inner structure. All species have a Kranz anatomy structure (Kochioid subtype), related to C4 photosynthesis. The changes in cell size increasing the cell membrane thickness, the density of two-vascular systems, the increase of palisade to water storage parenchyma ratio and photosynthetic system. The leaf surface is covered with long highly dense hairs and microechinate ornamentation. Though the adaptation caused some morphological similarities, the variation was seen in other descriptive characteristics such as morphological and anatomical features especially in two synonym species of B. turkestanica and B. pilosa. Information about the similarity species is provided. [ABSTRACT FROM AUTHOR]

Our group previously reported five quantitative trait loci (QTL) associated with plant height, test weight, thousand-kernel weight, and grain protein content in a recombinant inbred line population derived from spring wheat (Triticum aestivum L.) cultivars ‘Attila’ and ‘CDC Go’, evaluated across three environments (2008–2010) under organic management and genotyped with 579 diversity arrays technology and Rht-B1 markers. No QTL was identified for flowering time, maturity, grain yield, and number of tillers across all three environments. In the present study, we reanalyzed the same phenotypic data with a subset of 1200 informative single-nucleotide polymorphic (SNP) markers out of the 90K SNP array and three gene-specific markers (Ppd-D1, Vrn-A1, and Rht-B1) to investigate if high marker density improves QTL detection. Here, five moderate- and eleven minor-effect QTLs were detected across all three organic environments using the new genotypic data, including 13 QTLs that were not previously detected. Up to five QTLs were detected for each trait, except grain protein content, which individually accounted for 5.5 to 18.8% of phenotypic variance. For each trait, the total phenotypic and genetic variance explained by all detected QTLs varied from 9.3 to 39.4 and from 24.6 to 96.8%, respectively, which was much greater than in our previous study. One of the moderate-effect QTLs on 5A was coincidental for flowering time and maturity and mapped close to the Vrn-A1 gene, while the second moderate-effect coincidental QTL on 4B was associated with both plant height and maturity but was 27 cM from the Rht-B1 gene. Results from this study provide additional information for wheat researchers and organic wheat breeders. [ABSTRACT FROM AUTHOR]

Opuntia genus belongs to the Cactaceae and includes a range of species from 75 to 250 originated from the Americas. Several Opuntia species represent useful sources of forage in many arid areas, and their cultivation is drastically increasing. However the taxonomic classification of these species is complicated by the lack of reliable morphological descriptors, the relevant phenotypic plasticity, and the frequency of natural hybridization and of polyploidy. In this study 31 genotypes selected for forage production including Opuntia ficus-indica and some related species were analyzed using SSR markers to establish their genetic variability and to elucidate phylogenetic relationships among cultivated genotypes and related species. The analysis of six loci allowed to univocally identify most of the accessions and confirmed the fact that their taxonomical classification is not congruent with the observed patterns of genetic diversity. Most of the accessions selected for forage production were grouped exhibiting a narrow genetic variation level and clustered separately from two reference O. ficus-indica genotypes, used for fruit production in Mediterranean area. NeighbourNet analysis displayed a low level of diversification among the forage Opuntia from Brazil suggesting they probably have common ancestors. This information will be useful to plan future breeding strategies aimed at the selection of improved genotypes to be cultivated in different areas. [ABSTRACT FROM AUTHOR]

Thermal time models for seed germination assume a continuum of rate responses in the sub-optimal temperature range. Generally, the models describe germination performance in non-dormant seeds at constant temperatures, yet alternating temperature (AT) is a feature of many natural environments. We studied the possible interacting effects of AT on germination progress in photoblastic seeds of three aromatic-medicinal Verbenaceae species in the genera Lippia and Aloysia. For Lippia turbinata f. turbinata and L. turbinata f. magnifolia seed, germination only occurred in light conditions, while for L. integrifolia and Aloysia citriodora it was significantly higher in the light than in darkness. Although relative light germination (RLG) was not different between constant and AT in the sub-optimal range, AT raised the base temperature for germination progress ( Tb) from ca. 3-6 °C in constant temperature to 7-12 °C in AT. Among the species, thermal time for 50% seed germination [θ T(50)] was 55-100 °Cd at constant temperature. Although AT resulted in slight modifications to θ T(50), the germination rate at comparable average temperatures in the sub-optimal range was slower than under constant temperatures. For all species, the proportion of germinated seeds was similar for constant and AT. Our results suggest that an interaction between cool temperature and darkness during AT treatment limits the temperature range permissive for germination in these positively photoblastic seed, reflecting both close adaptation to the natural ecology and niche requirements of the species. [ABSTRACT FROM AUTHOR]

Background and Aims Plasticity of floral traits in response to pollination can enable plants to maximize opportunities for pollen import and export under poor pollination conditions, while minimizing costs under favourable ones. Both floral longevity and display are key traits influencing pollination. While pollination-induced flower wilting is widely documented, we lack an understanding of the multifactorial complexity of this response, including the influence of other pollination components, costs of extended longevity and subsequent impacts on floral display. Methods Plasticity of floral longevity was experimentally evaluated in Sabatia angularis in response to multiple pollination factors: pollen addition, removal, and source (self, single-donor outcross, multiple-donor outcross) and timing of pollination. Effects of pollen quantity were further evaluated by exploiting variation in autonomous self-pollen deposition. Delayed pollination costs were tested comparing seed set from early versus late pollinations. Finally, I compared floral display metrics (peak floral display, time to peak flower, flowering duration, mean flowering rate) between experimentally pollinated and control plants. Key Results Floral longevity was highly plastic in response to pollen addition and its timing, and the response was dose-dependent but insensitive to pollen source. Pollen removal tended to extend floral longevity, but only insofar as it precluded pollination-induced wilting via autonomous self-pollination. Under delayed pollination, the wilting response was faster and no cost was detected. Pollination further led to reduced peak floral displays and condensed flowering periods. Conclusions Floral longevity and display plasticity could optimize fitness in S. angularis, a species prone to pollen limitation and high inbreeding depression. Under pollinator scarcity, extended floral longevities offer greater opportunities for pollen receipt and export at no cost to seed set, reproductive assurance via autonomous self-pollination and larger, more attractive floral displays. Under high pollinator availability, shortened longevities lead to smaller displays that should lower the risk of geitonogamy. [ABSTRACT FROM AUTHOR]

The availability of water is often highly variable over the life of a plant in nature, and most plants experience episodic extremes in water scarcity and abundance. The importance of plant plasticity in coping with such experiences is widely recognized, but little is known about how plastic responses to current conditions are affected by prior environmental experiences., Our objectives were to investigate the effects of early inundation or drought on the subsequent responses of plant species to the same, opposite or more favourable conditions., To address these questions, we subjected four invasive and four native herbaceous perennial species from different habitats (xeric, mesic, hydric) to two rounds of hydrological treatments (drought, moderate water, inundation) and analysed the effects of the early treatments on survival and performance (total biomass and relative growth) of individuals in the later treatments., In general, (i) early drought reduced the performance of more species than did early inundation, and decreased the final total mass of all species; (ii) early inundation and early drought did not lead to lower survival immediately or later, but improved the relative growth of survivors across all late conditions; (iii) late drought resulted in the highest mortality and lowest performance after any early treatment., With respect to habitat of origin: (i) early inundation was more beneficial for species from wet habitats than for other species; (ii) species from xeric habitats had the strongest drought tolerance after early drought; (iii) mesic species were more likely to suffer reduced later growth after either inundation or drought experience. Invasive species benefitted more from early inundation than did native species, but native species grew better after experiencing early drought., Results indicate that early exposure to inundation or drought conditions alters how plants respond to later conditions and suggest that exposure to extreme events can induce physiological or morphological changes that improve tolerance for either extreme conditions later. This increased tolerance can be at the cost of poorer performance under more benign conditions., Synthesis. Early inundation or drought experience may be harmful immediately, but can be beneficial for the later growth of plants. The ability of species to utilize early hydrological experiences was associated with the water range of their habitats and whether the species is invasive or native. The ability to modulate future plastic responses may be as important as short-term plasticity in adapting to temporal environmental heterogeneity. Such 'metaplasticity' can optimize current performance, while avoiding the potential costs of maintaining a high degree of plasticity throughout life. [ABSTRACT FROM AUTHOR]

The habitats of polyploid species are generally distinct from their parental species. Stebbins described polyploids as 'general purpose genotypes', which can tolerate a wide range of environmental conditions. However, little is known about its molecular basis because of the complexity of polyploid genomes. We hypothesized that allopolyploid species might utilize the expression patterns of both parents depending on environments (polyploid plasticity hypothesis). We focused on hydrological niche segregation along fine-scale soil moisture and waterlogging gradients. Two diploid species, Cardamine amara and Cardamine hirsuta, grew best in submerged and unsubmerged conditions, respectively, consistent with their natural habitats. Interestingly, the allotetraploid Cardamine flexuosa derived from them grew similarly in fluctuating as well as submerged and unsubmerged conditions, consistent with its wide environmental tolerance. A similar pattern was found in another species trio: allotetraploid Cardamine scutata and its parents. Using the close relatedness of Cardamine and Arabidopsis, we quantified genomewide expression patterns following dry and wet treatments using an Arabidopsis microarray. Hierarchical clustering analysis revealed that the expression pattern of C. flexuosa clustered with C. hirsuta in the dry condition and with C. amara in the wet condition, supporting our hypothesis. Furthermore, the induction levels of most genes in the allopolyploid were lower than in a specialist diploid species. This reflects a disadvantage of being allopolyploid arising from fixed heterozygosity. We propose that recurrent allopolyploid speciation along soil moisture and waterlogging gradients confers niche differentiation and reproductive isolation simultaneously and serves as a model for studying the molecular basis of ecological speciation and adaptive radiation. [ABSTRACT FROM AUTHOR]

Many studies investigated temperature effects on leaf initiation and expansion by relating these processes to air temperature or the temperature of a specific organ (e.g. leaf temperature). In reality plant temperature is hardly ever equal to air temperature or spatially uniform. Apical bud temperature ( Tbud), for example, may greatly differ from the temperature of the rest of the plant ( Tplant) dependent on the environment. Recent research in Cucumis sativus showed that Tbud influences leaf initiation independent of Tplant. These findings trigger the question if such spatial temperature differences also influence leaf expansion and plant phenotype. In a 28 day study, we maintained temperature differences between Tbud and Tplant ranging from −7 to +8 °C using a custom-made bud temperature control system. Leaf expansion did not only depend on leaf temperature but also on the difference between bud and leaf temperature. Differences between Tbud and Tplant considerably influenced vertical leaf area distribution over the shoot: increasing Tbud beyond Tplant resulted in more and smaller leaves, while decreasing Tbud below Tplant resulted in less and larger leaves. The trade-off between leaf number and leaf area resulted in phenotypic alterations that cannot be predicted, for example, by crop models, when assuming plant temperature uniformity. [ABSTRACT FROM AUTHOR]

There is an ongoing debate to which extent the phenotypic plasticity is associated with the shade-tolerance of species along a broad environmental gradient. Seedlings of five species of varying shade tolerance were grown under each of the four combinations of high and low light or nutrient availabilities in shade houses. Leaf, fine root and whole-plant traits were measured to evaluate the phenotypic plasticity in seedlings of five species in response to light and nutrition gradients. Generally, leaf nitrogen and phosphorus concentrations, specific leaf area (SLA), leaf area ratio, specific fine-root length and surface area (SRL, SRSA), leaf mass ratio, and relative growth rate decreased, whereas total root mass ratio increased with increasing shade tolerance of species, indicating light-demanding species had higher ability to capture above- and below-ground resources and thus had higher growth rate than shade-tolerant species. Light was a more important limiting factor than soil nutrients for the five studied species; and the light responsiveness at different nutrient availability for most morphological variables was similar among different species. In response to light and nutrient gradients, the mean plasticity index of all variables measured did not differ significantly among the five species, indicating that the species with contrasting shade tolerance have similar plasticity. There were significantly positive correlations in leaf area (mass) and fine-root surface area (mass) for each species along light and nutrient gradients. Moreover, there were significant correlations between leaf and fine-root nitrogen and phosphorus concentrations, leaf area and fine-root surface area, SLA and SRL or SRSA across all species and treatments. Our result thus provided an evidence of a common leaf and root traits syndrome linking traits to effects on plant and ecosystem process. [ABSTRACT FROM AUTHOR]

Increasing evidence suggests that nocturnal transpiration rate (TRN) is a non-negligible contributor to global water cycles. Short-term variation in nocturnal vapor pressure deficit (VPDN) has been suggested to be a key environmental variable influencing TRN. However, the long-term effects of VPDN on plant growth and development remain unknown, despite recent evidence documenting long-term effects of daytime VPD on plant anatomy, growth and productivity. Here we hypothesized that plant anatomical and functional traits influencing leaf and root hydraulics could be influenced by long-term exposure to VPDN. A total of 23 leaf and root traits were examined on four wheat (Triticum aestivum) genotypes, which were subjected to two long-term (30 day long) growth experiments where daytime VPD and daytime/nighttime temperature regimes were kept identical, with variation only stemming from VPDN, imposed at two levels (0.4 and 1.4 kPa). The VPDN treatment did not influence phenology, leaf areas, dry weights, number of tillers or their dry weights, consistently with a drought and temperature-independent treatment. In contrast, vein densities, adaxial stomata densities, TRN and cuticular TR, were strongly increased following exposure to high VPDN. Simultaneously, whole-root system xylem sap exudation and seminal root endodermis thickness were decreased, hypothetically indicating a change in root hydraulic properties. Overall these results suggest that plants 'sense' and adapt to variations in VPDN conditions over developmental scales by optimizing both leaf and root hydraulics. [ABSTRACT FROM AUTHOR]

Copyright of Czech Mycology is the property of Czech Scientific Society for Mycology 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.)

This paper presents a discovery: the change of the outline shape of mistletoe (Viscum album ssp. album) berries in vivo and in situ during ripening. It was found that a plant organ that is usually considered to merely increase in size actually changes shape in a specific rhythmic fashion. We introduce a new approach to chronobiological research on a macro-phenotypic scale to trace changes over long periods of time (with a resolution from hours to months) by using a dynamic form-determining parameter called Lambda (λ). λ is known in projective geometry as a measure for pertinent features of the outline shapes of egg-like forms, so called path curves. Ascertained circadian changes of form were analyzed for their correlation with environmental factors such as light, temperature, and other weather influences. Certain weather conditions such as sky cover, i.e., sunshine minutes per hour, have an impact on the amplitude of the daily change in form. The present paper suggests a possible supplement to established methods in chronobiology, as in this case the dynamic of form-change becomes a measurable feature, displaying a convincing accordance between mathematical rule and plant shape. [ABSTRACT FROM AUTHOR]

Prunus spinosa is a highly esteemed shrub in forest and landscape plantings. Shrubs with larger organs occur often and are considered either as large fruited forms of P. spinosa or as P. x fruticans, involving a hybridization process with the ancient cultivated P. insititia (crop-to-wild gene flow). As climate change may augment hybridization processes in the future, a hybrid origin is important to detect. In addition, studying crop-to-wild gene flow can give insights in putative consequences for the wild populations. We studied the P. spinosa-P. x fruticans group, focusing on morphology and phenology in three experimental plantations. Two plantings harbored cuttings of P. spinosa (clone plantations). A third plantation comprised of a half-sib offspring from a population with both P. spinosa and P. x fruticans (family plantation). Several results point to a hybridization process as the origin of P. x fruticans. The clone plantation revealed endocarp traits to be more genetically controlled than fruit size, while this was the opposite in the family plantation, suggesting the control of fruit size being derived from the putative P. insititia parent. Bud burst, flower opening, and leaf fall were genetically controlled in the clone plantation, whereas in the family plantation intrafamily variability was remarkably large for the bud burst and leaf fall, but not for the flower opening. This suggests there is a reduced genetic control for the first two phenophases, possibly caused by historic hybridization events. Pubescence on the long shoot leaves in the family plantation deviated from the short shoot leaves on the same plants and from long and short shoot leaves in the clone plantation, suggesting again a P. insititia origin. Finally, we quantified spatial phenotypic plasticity, indicating how P. spinosa may react in a changing environment. In contrast to the bud burst and leaf fall, flower opening did not demonstrate plasticity. The fruit size was diminished at the growth site with the shortest growing season while interestingly, the leaf width was enlarged. Leaf size traits appeared more plastic on the long shoots compared to the short shoots, although partitioning of variance did not display a lesser genetic control. [ABSTRACT FROM AUTHOR]

Global environmental changes can create novel habitats, promoting the growth of alien plants that often exhibit broad environmental tolerance and high phenotypic plasticity. However, the mechanisms underlying these growth promotory effects are unknown at present. Here, we conducted a phylogenetically controlled meta-analysis using data from 111 published studies encompassing the responses of 129 alien plants to global warming, increased precipitation, N deposition, and CO2 enrichment. We compared the differences in the responses of alien plants to the four global environmental change factors across six categories of functional traits between woody and non-woody life forms as well as C3 and C4 photosynthetic pathways. Our results showed that all four global change factors promote alien plant growth. Warming had a more positive effect on C4 than C3 plants. Although the effects of the four factors on the functional traits of alien plants were variable, plant growth was mainly promoted via an increase in growth rate and size. Our data suggest that potential future global environmental changes could further facilitate alien plant growth. [ABSTRACT FROM AUTHOR]

Phenotypic plasticity is thought to be important for plants in variable environments. The climatic variability hypothesis poses that populations at higher latitudes, due to the stronger variation in temperature, there should be more plastic in response to temperature than populations at lower latitudes. Similarly, populations at locations with stronger precipitation fluctuations should be more plastic in response to water availability than populations at locations with less variable precipitation. We sampled seven and nine populations of Solidago canadensis, a North American native that is invasive in China, along a latitudinal (temperature variability) and a longitudinal (precipitation variability) gradient, respectively, in China, and grew them under two temperature treatments and two water-availability treatments, respectively. Among the four traits with significant variation in plasticity among populations in response to temperature, plasticity of leaf length-to-width ratio was significantly positively correlated with latitude and temperature seasonality of the populations. In addition, root/shoot ratio and water-use efficiency showed significant variation in plasticity among populations in response to water availability, and plasticities of these two traits were significantly negatively correlated with longitude and positively correlated with precipitation seasonality. The observed geographic clines in plasticity suggest that phenotypic plasticity of S. canadensis may have evolved rapidly in regions with different climatic conditions, and this may have contributed to the spread of this invasive species. [ABSTRACT FROM AUTHOR]

The differences in leaf functional traits between invasive and native species are considered to be closely linked to the mechanisms underlying successful plant invasion because co-occurring invasive and native species experience similar or even identical environmental selective pressures. This study aims to determine the differences in leaf functional traits and resource-use strategy between the invader Rhus typhina and the native species Sapindus mukorossi. Leaf chlorophyll and nitrogen concentrations, specific leaf area (SLA), and leaf moisture of R. typhina were significantly higher than those of S. mukorossi, but leaf length, leaf width, and single-leaf wet and dry weights of R. typhina were significantly lower than those of S. mukorossi. Plasticity indices of leaf shape index and SLA of R. typhina were obviously higher than those of S. mukorossi, while plasticity indices of single-leaf wet and dry weights, and leaf moisture of R. typhina were obviously lower than those of S. mukorossi. The higher leaf chlorophyll and nitrogen concentrations, SLA, and leaf moisture as well as the high range of phenotypic plasticity of leaf shape index and SLA for R. typhina may confer it a competitive advantage and thus play an important role in its successful invasion. [ABSTRACT FROM AUTHOR]

Premise of research. The Canadian Arctic Archipelago is experiencing unprecedented climate change with temperatures rising at a rate that is twice the global average. The rapidly rising temperatures will likely impact plant phenology dramatically. The Canadian Arctic Archipelago is remote and difficult to reach, and there are few insights into the phenology of its plants. Data on current Arctic plant flowering times and how they vary across the Canadian Arctic Archipelago are needed to form a baseline to facilitate studies on the impact of climate change on Arctic plant phenology. Methodology. We recorded the flowering times of 26 species from 12 families that are common to high- Arctic (lat. 81°N) and mid-Artic (lat. 63°N) locations in Nunavut, Canada, in 2013 and 2014. We compared differences in flowering times and flower abundance between the two locations and identified factors that might explain the differences. Pivotal results. Species flowered at the same time or earlier and for a shorter duration at the high-Arctic location than at the mid-Arctic location. Different sublocales at a location explained more of the variation in flowering time than did mid- versus high-Arctic location or elevation. Peak flowering occurred one-third of the way through flowering. Plants at the mid-Arctic location produced more flowers per plant than did plants at the high-Arctic location. Relative order of species' flowering is consistent between the mid- and high-Arctic locations and between years. Conclusions. Earlier flowering times of more northerly conspecifics are contrary to what might be expected given that temperatures are colder at the high-Arctic location than at the mid-Arctic location and that flowering time for a species is influenced by cumulative temperatures above a threshold. Our results suggest that plants at the northern location might be evolutionarily adapted to the shorter growing season and that plants have phenotypic plasticity across sublocales. [ABSTRACT FROM AUTHOR]

Background and aims: Determining which strategies confer a competitive advantage in variable environments with strong short-term resource fluctuations (i.e., seasonal drought and flooding) is critical for understanding ecosystem structure and function, and predicting how ecosystems will respond to global change. Here, we ask how functional traits of plant species vary in response to drought and flooding and whether trait plasticity is a better predictor of plants' cover than average functional trait values. Methods: We transplanted vegetative recruits (similar size and age) of eight common species from a moderately grazed alpine wetland in the Eastern Tibetan Plateau to a common garden where we evaluated the trait responses of these species to drought and flooding. We also measured the coverage, biomass, and height of these plant species in the field communities. Results: The leaf morphological and physiological traits of these eight species generally showed different responses to drought and flood conditions. Variation (plasticity) of leaf morphological or physiological traits rather than average values of these traits were better predictors of cover and biomass in the field community. Species with lower plasticity in leaf morphological traits had higher plasticity in leaf physiology and the higher coverage and biomass in the field community. Conclusions: Our results suggest that the ability to quickly adjust leaf physiology to changing environmental conditions provides an advantage in this ecosystem, where intra-annual rainfall variability is high and thus resource fluctuations are pulsed in time. In contrast, greater functional trait plasticity in leaf morphology was a disadvantage, possibly because the benefits of these adjustments did not outweigh their initial costs. [ABSTRACT FROM AUTHOR]

The article presents a study which aims to examine the cost of resistance and selection of Solanum carolinense. It mentions the proportion of tissues from nine species of herbivores, the quadratic phenotypic-selection analysis on 12 types of resistance, and the genetic variation of plants. Also discussed are the evolutionary ecology of resistance to herbivores.

Aims Foliar herbivory and water stress may affect floral traits attractive to pollinators. Plant genotypes may differ in their responses to the interplay between these factors, and evolution of phenotypic plasticity could be expected, particularly in heterogeneous environments. We aimed at evaluating the effects of simulated herbivory and experimental drought on floral traits attractive to pollinators in genetic families of the annual tarweed Madia sativa, which inhabits heterogeneous environments in terms of water availability, herbivore abundance and pollinator abundance. Methods In a greenhouse experiment with 15 inbred lines from a M. sativa population located in central Chile (Mediterranean-type climate), we measured the effects of apical bud damage and reduced water availability on: number of ray florets per flower head, length of ray florets, flower head diameter, number of open flower heads per plant, flowering plant height and flowering time. Important Findings Apical damage and water shortage reduced phenotypic expression of floral traits attractive to pollinators via additive and non-additive effects. Plants in low water showed decreased height and had fewer and shorter ray florets, and fewer and smaller flower heads. Damaged plants showed delayed flowering, were less tall, and showed shorter ray florets and smaller flower heads. The number of ray florets was reduced by damage only in the low water treatment. Plant height, flowering time and number of flower heads showed among-family variation. These traits also showed genetic variation for plasticity to water availability. Ray floret length, flower head size and time to flowering showed genetic variation for plastic responses to apical damage. Plasticity in flowering time may allow M. sativa to adjust to the increased aridity foreseen for its habitat. Because genetic variation for plastic responses was detected, conditions are given for evolutionary responses to selective forces acting on plastic traits. We suggest that the evolution of adaptive floral plasticity in M. sativa in this ecological scenario (heterogeneous environments) would result from selective forces that include not only pollinators but also resource availability and herbivore damage. [ABSTRACT FROM AUTHOR]

Copyright of American Journal of Potato Research 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.)

Phenotypic plasticity describes the range of phenotypes produced by a single genotype in different environments. We quantified the extent of phenotypic plasticity (evaluated as responsiveness to varying environmental conditions) of thermal time to heading and grain yield in 299 hard winter wheat (Triticum aestivum L) genotypes from the US Great Plains. The genotypes, which included advanced breeding lines and recent and historic cultivars, were evaluated in 11 environments in 2011-2012 and 2012-2013. The average number of days from 1 January to heading across environments ranged from 109 to 150, and the cumulative growing degree days (GDD) from 1 January to heading ranged from 730 to 1112 GDD. Environmental mean grain yield varied from 1.3 to 5.3 Mg ha-1. Plasticity of GDD (GDDP) was strongly correlated with GDD (r = 0.81, P < 0.001), especially maximum GDD (r = 0.90, P < 0.001) across environments, indicating genotypes with greater plasticity developed later, especially within the earliest environments. Plasticity of GDD was negatively associated with yield (r = -0.58, P < 0.001) and therefore detrimental in the germplasm and environments evaluated. Yield plasticity of a genotype was positively correlated with its maximum (r = 0.80, P < 0.001) and minimum (r = 0.33, P < 0.001) grain yield across environments, indicating greater plasticity was favorable under optimal conditions, without a penalty under low-yielding conditions. More than a century of wheat breeding in this region suggests GDDP has declined and yield plasticity has increased at similar rates. This is encouraging because it indicates the favorable plasticity traits (high yield plasticity, low GDDP) have been selected for indirectly and would respond to further selection. [ABSTRACT FROM AUTHOR]

The colony forming phytoplankton species Phaeocystis pouchetii plays a key role in nutrient turnover and the fixation of inorganic carbon in the Arctic and sub-Arctic Ocean. In the Fram Strait, salinity is a variable parameter due to freezing and melting processes of sea ice and due to a bidirectional current regime providing the exchange of water masses between the Arctic and Atlantic Ocean. We tested the growth response of seven P. pouchetii strains to six different salinities (7-60) in order to identify ecotypes adapted to specific environmental regimes. The experimental setup was realized by means of a custom-build incubator enabling ecophysiological treatments at low temperatures combined with high irradiances. Salinity tolerance showed a heterogenic, strain specific pattern varying from broad (salinity < 7 to > 60) to relatively narrow ranges (salinity 33-45) indicating an ecophysiological differentiation which is rather dependent on the sampling period than on the geographical origin. In order to confirm these findings it is however necessary to obtain data from strains isolated in the same year or even from the same bloom. The ecotype question can only be solved when methodical constraints concerning molecular taxonomy of P. pouchetii are resolved. [ABSTRACT FROM AUTHOR]

Plants make foraging decisions that are dependent on ecological conditions, such as resource availability and distribution. Despite the field of plant behavioral ecology gaining momentum, ecologists still know little about what factors impact plant behavior, especially light-foraging behavior. We made use of the behavioral reaction norm approach to investigate light foraging in a plant species that exhibits rapid movement: Mimosa pudica. We explored how herbivore avoidance behavior in M. pudica (which closes its leaflets temporarily when disturbed) is affected by an individual's energy state and the quality of the current environment and also repeatedly tested the behavior of individuals from two seed sources to determine whether individuals exhibit a 'personality' (i.e., behavioral syndrome). We found that when individuals are in a low-energy state, they adopt a riskier light-foraging strategy, opening leaflets faster, and not closing leaflets as often in response to a disturbance. However, when plants are in a high-energy state, they exhibit a plastic light-foraging strategy dependent on environment quality. Although we found no evidence that individuals exhibit behavioral syndromes, we found that individuals from different seed sources consistently behave differently from each other. Our results suggest that plants are capable of making state-dependent decisions and that plant decision making is complex, depending on the interplay between internal and external factors. [ABSTRACT FROM AUTHOR]

A large environmental influence on phenotypic estimates of spot blotch (SB) resistance and the complex polygenic nature of SB resistance in barley (Hordeum vulgareL.) are a limitation to developing resistant cultivars. Component-based polygenic resistance would help in selecting lines with durable resistance. The objective of this research was to investigate the genetics of three important components of resistance to spot blotch caused byBipolaris sorokiniana(Sacc.) Shoemaker. A total of 124 genotypes were evaluated and two most diverse genotypes each for latent period (LP), number of lesions (NL), and spore production (SP) were selected. To determine the inheritance of LP, NL, and SP, selected diverse genotypes were crossed and advanced to F2, F3, and F4generations. Inheritance pattern indicated that LP was controlled by 2–3 effective genes, whereas NL and SP were controlled by three genes each. Across the segregating generations, SP and NL showed positive (r = 0.68–0.82) and LP showed negative (r = −0.78–−0.88) association with area under disease progress curve (AUDPC). Narrow-sense heritability estimated by regression of F4progenies on F3generation was 0.81 for LP, 0.78 for NL and 0.67 for SP. Transgressive segregants were observed for latency period in all segregating generations. These results should help in the development of durable resistance against spot blotch. Identified transgressive segregants for spot blotch resistance could be utilized directly as cultivars after multilocation/multienvironment evaluation and/or could be used as donors to introgress spot blotch resistance into other improved backgrounds. [ABSTRACT FROM PUBLISHER]

Geographical variation in the interacting traits of plant-pollinator mutualism can lead to local adaptive differentiation. We tested Darwin's hypothesis of reciprocal selection as a key driving force for the evolution of floral traits of an alpine ginger ( Roscoea purpurea) and proboscis length of a tabanid fly ( Philoliche longirostris)., We documented the pattern of trait variation in R. purpurea and P. longirostris across five populations. At each site, we quantified pollinator-mediated selection on floral display area, inflorescence height and corolla length of R. purpurea by comparing selection gradients for flowers exposed to natural pollination and to supplemental hand pollination. Reciprocal selection between plant and fly was examined at two sites via the relationship between proboscis length and nectar consumption (fly benefit) and corolla length and pollen deposition (plant benefit)., Local corolla tube length was correlated with local fly proboscis length among the five sites. We found strong linear selection imposed by pollinators on corolla tube length at all sites, but there was no consistent relationship of fitness to inflorescence height or floral display area. Selection between corolla length and proboscis length was reciprocal at the two experimental sites examined., The geographical pattern of trait variation and the evidence of selection is consistent with a mosaic of local, species-specific reciprocal selection acting as the major driving force for the evolution of corolla length of R. purpurea and proboscis length of P. longirostris. [ABSTRACT FROM AUTHOR]

Plant-associated mycobiomes in extreme habitats are understudied and poorly understood., We analysed Illumina-generated ITS1 sequences from the needle mycobiome of white spruce ( Picea glauca) at the northern treeline in Alaska (USA). Sequences were obtained from the same DNA that was used for tree genotyping. In the present study, fungal metabarcoding and tree microsatellite data were compared for the first time., In general, neighbouring trees shared more fungal taxa with each other than trees growing in further distance. Mycobiomes correlated strongly with phenological host traits and local habitat characteristics contrasting a dense forest stand with an open treeline site. Genetic similarity between trees did not influence fungal composition and no significant correlation existed between needle mycobiome and tree genotype., Our results suggest the pronounced influence of local habitat conditions and phenotypic tree traits on needle-inhabiting fungi. By contrast, the tree genetic identity cannot be benchmarked as a dominant driver for needle-inhabiting mycobiomes, at least not for white spruce in this extreme environment. [ABSTRACT FROM AUTHOR]

To determine the phenotypic variation in 700 ten-year grafted Chinese fir collected from six provinces in southern China, 10 phenotypic traits were investigated: tree height, diameter at breast height, bark thickness, volume of timber, heartwood ratio, density of wood, hygroscopicity, tracheid length, tracheid diameter, and ratio of tracheid length to tracheid diameter. Abundant phenotypic variation was found among the six populations; the phenotypic variation coefficients all exceeded 10%, and the largest was for volume of timber. Significant variation (p < 0.01 or 0.05) in traits was found among the populations, except for diameter at breast height, heartwood ratio, and tracheid diameter, while all traits differed significantly (p < 0.01) within populations. The high value of repeatability (broad-sense heritability) suggested moderate genetic control of the traits. The 10 traits were strongly correlated within the entire population; strong positive correlations (p < 0.01) were observed between growth traits, and significant negative correlations (p < 0.01 or 0.05) were found between the density of wood and most other characteristics, except for heartwood ratio and ratio of tracheid length to tracheid diameter. Using diameter at breast height and density of wood as criteria, 98 relatively fast-growing genotypes with relatively high wood basic density were identified. [ABSTRACT FROM AUTHOR]

Castor ( Ricinus communis L.) is an important oilseed crop providing raw materials for many industries. Its cultivation is seriously affected by the wilt disease caused by Fusarium oxysporum f. sp. ricini. In India, no cultivar could be released for cultivation without wilt resistance. Breeding for wilt resistance is hampered due to the limitation on number of genotypes that can be screened in a traditional 'sick plot (field) method'. In the pursuit of establishing a high throughput screening method, we evaluated four different methods of artificial inoculation namely seed soaking, soil drenching, root dip and sick pot in glasshouse condition for their efficiency using a panel of eight genotypes with known disease reaction. The results showed that 'sick pot method' was the most ideal for accurate identification of resistance or susceptibility in plants in a short time with relative ease. In order to further validate the results, a large set of 132 castor inbred lines were evaluated in sick pot. Based on days-to-death data of the inbred lines, a scoring system was developed to suitably characterize the degree of resistance. Screening of the same set of inbred lines in the sick field produced similar results but moderate and highly resistant genotypes could not be differentiated suggesting the advantage of sick pot method over field screening. The screening method established and the set of resistant or susceptible inbred lines identified in this study could be of immense use in basic research concerning host-pathogen interactions, molecular genetics and breeding applications in castor. [ABSTRACT FROM AUTHOR]

Background: Local adaptation and phenotypic plasticity are important components of plant responses to variations in environmental conditions. While local adaptation has been widely studied in trees, little is known about plasticity of gene expression in adult trees in response to ever changing environmental conditions in natural habitats. Here we investigate plasticity of gene expression in needle tissue between two Douglas-fir provenances represented by 25 adult trees using deep RNA sequencing (RNA-Seq). Results: Using linear mixed models we investigated the effect of temperature, soil water availability and photoperiod on the abundance of 59189 detected transcripts. Expression of more than 80 % of all identified transcripts revealed a response to variations in environmental conditions in the field. GO term overrepresentation analysis revealed gene expression responses to temperature, soil water availability and photoperiod that are highly conserved among many plant taxa. However, expression differences between the two Douglas-fir provenances were rather small compared to the expression differences observed between individual trees. Although the effect of environment on global transcript expression was high, the observed genotype by environment (GxE) interaction of gene expression was surprisingly low, since only 21 of all detected transcripts showed a GxE interaction. Conclusions: The majority of the transcriptome responses in plant leaf tissue is driven by variations in environmental conditions. The small variation between individuals and populations suggests strong conservation of this response within Douglas-fir. Therefore we conclude that plastic transcriptome responses to variations in environmental conditions are only weakly affected by local adaptation in Douglas-fir. [ABSTRACT FROM AUTHOR]

Stigma traits are very important for hybrid seed production in Oryza sativa, which is a self-pollinated crop; however, the genetic mechanism controlling the traits is poorly understood. In this study, we investigated the phenotypic data of 227 accessions across 2 years and assessed their genotypic variation with 249 simple sequence repeat (SSR) markers. By combining phenotypic and genotypic data, a genome-wide association (GWA) map was generated. Large phenotypic variations in stigma length (STL), stigma brush-shaped part length (SBPL) and stigma non-brush-shaped part length (SNBPL) were found. Significant positive correlations were identified among stigma traits. In total, 2072 alleles were detected among 227 accessions, with an average of 8.3 alleles per SSR locus. GWA mapping detected 6 quantitative trait loci (QTLs) for the STL, 2 QTLs for the SBPL and 7 QTLs for the SNBPL. Eleven, 5, and 12 elite alleles were found for the STL, SBPL, and SNBPL, respectively. Optimal cross designs were predicted for improving the target traits. The detected genetic variation in stigma traits and QTLs provides helpful information for cloning candidate STL genes and breeding rice cultivars with longer STLs in the future. [ABSTRACT FROM AUTHOR]

As a response to current climate changes, individual species have changed various biological traits, illustrating an inherent phenotypic plasticity. However, as species are embedded in an ecological network characterised by multiple consumer-resource interactions, ecological mismatches are likely to arise when interacting species do not respond homogeneously. The approach of biological networks analysis calls for the use of structural equation modelling (SEM), a multidimensional analytical setup that has proven particularly useful for analysing multiple interactions across trophic levels. Here we apply SEM to a long-term dataset from a High-Arctic ecosystem to analyse how phenological responses across three trophic levels are coupled to snowmelt patterns and how changes may cascade through consumer-resource interactions. Specifically, the model included the effect of snowmelt on a High-Arctic tri-trophic system of flowers, insects and waders (Charadriiformes), with latent factors representing phenology (timing of life history events) and performance (abundance or reproduction success) for each trophic level. The effects derived from the model demonstrated that the time of snowmelt directly affected plant and arthropod phenology as well as the performance of all included trophic levels. Additionally, timing of snowmelt appeared to indirectly influence wader phenology as well as plant, arthropod and wader performance through effects on adjacent trophic levels and lagged effects. The results from the tri-trophic community presented here emphasise that effects of climate on species in consumer-resource systems may propagate through trophic levels. [ABSTRACT FROM AUTHOR]

Plant strategy and life-history theories make different predictions about reproductive efficiency under competition. While strategy theory suggests under intense competition iteroparous perennial plants delay reproduction and semelparous annuals reproduce quickly, life-history theory predicts both annual and perennial plants increase resource allocation to reproduction under intense competition. We tested (1) how simulated competition influences reproductive efficiency and competitive ability (CA) of different plant life histories and growth forms; (2) whether life history or growth form is associated with CA; (3) whether shade avoidance plasticity is connected to reproductive efficiency under simulated competition. We examined plastic responses of 11 herbaceous species representing different life histories and growth forms to simulated competition (spectral shade). We found that both annual and perennial plants invested more to reproduction under simulated competition in accordance with life-history theory predictions. There was no significant difference between competitive abilities of different life histories, but across growth forms, erect species expressed greater CA (in terms of leaf number) than other growth forms. We also found that shade avoidance plasticity can increase the reproductive efficiency by capitalizing on the early life resource acquisition and conversion of these resources into reproduction. Therefore, we suggest that a reassessment of the interpretation of shade avoidance plasticity is necessary by revealing its role in reproduction, not only in competition of plants. [ABSTRACT FROM AUTHOR]