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Salt stress is a major problem at the global level and it is very important to utilize salt-affected soils using appropriate techniques. Growing halophytes on saline-sodic soil is a win-win strategy for getting economic crop production and conservation of soil resources. However, it is prerequisite to identify the cultivars which can be recommended for salt-affected soils considering physiological and biochemical responses under salt-stress. Therefore, sugar beet cultivars were characterized at seedling stage based on growth, physiological and biochemical parameters under different levels of salt stress. A hydroponic experiment was conducted using eight sugar beet cultivars (AMALDI, GELLERT, VANGELIS, VEDA, WYNNYK, SERENADA, CALIFORNIA and ALBINA VEREDUANA) and two salt stress levels (60 and 120 mM NaCl) in comparison with that of an untreated control. The plants were harvested ten days after giving salt stress. Cluster dendrogram and principal component analysis were the most appropriate methods for screening the suitable cultivar. Most of the sugar beet cultivars responded as resistant against salt stress, however, VEDA cultivar performed best against it. Thus, VEDA cultivar acquired highest position at 60 mM NaCl showing 6.4% plant biomass improvement as compared to control, while 2.1% reduction was recorded at 120 mM NaCl as compared to 60 mM NaCl. Additionally, this cultivar showed highest growth attributes, antioxidant activity with higher K+/Na+ ratio, hydrogen peroxide, phenolic and malondialdehyde content, indicating strong defense mechanism against salt induced oxidative and osmotic stress mainly owing to the best K+ and Na+ balance. It is concluded from this study that VEDA is the best salt-resistant cultivar with great potential to be grown on salt-affected soils and can be proceeded for field trials at various salt-stress levels. [ABSTRACT FROM AUTHOR]

Seventy diverse genotypes were evaluated for drought stress for morphological traits i.e. days to flowering, days to maturity, head diameter, number of leaves per plant, stem girth, thousand seed weight, achene yield per plant and oil percentage to find out trait specific genotypes. All genotypes showed highly significant (P ≤ 0.01) mean square values for all traits. Head diameter expressed highest and significant genotype mean square (5366.93) and days to flowering showed lowest but significant genotype mean square (23.71) in all traits. Achene yield per plant and thousand seed weight having high heritability with increased genetic advance indicated additive gene action and lesser influence of the environment. The characters like days to flowering, days to maturity, head diameter, number of leaves per plant, stem girth and oil percentage showed non-additive gene action. Genotypes ORI 29 and ORI 30 performed better in normal and drought stress conditions that could be used as a drought tolerant material. In Principle Component Analysis (PCA), genotypes RL 110, RL 109, ORI 58, ORI 22, ORI 30 and RL 77 expressed maximum diversity. The bi-plot graph presented that genotype RL 104 had maximum number of leaves per plant, ORI 88 had maximum stem girth and head diameter; however, ORI 25 had high oil percentage value while days to maturity and achene yield per plant were found higher in ORI-66 and ORI-101 under normal and drought stress conditions. The trait-specific accessions will be helpful in effective exploitation of prominent genotypes for drought tolerant breeding programme. Drought tolerant genotypic identification could overcome the shortage of edible oil in country by increasing area and production under arid & semi-arid climatic condition. [ABSTRACT FROM AUTHOR]

Chlorpyrifos (CP) is a toxic and broad-spectrum pesticide. Owing to the extensive soil and crop application of CP to control insects/pests, its significant concentrations have been reported in different crop plants, fruits, vegetables and other food items locally and internationally. The strategies to immobilize pesticide residues in the soil are of great concern to restrict their offsite transport. A batch study was conducted to evaluate the potential of biochar and compost in enhancing CP sorption. Soil samples were supplemented with biochar and compost at two levels, i.e. 0.25% and 0.50% w/w basis. The sorption of CP was assessed at five applied concentrations viz. 5, 10, 50, 100 and 200 mg L-1. CP sorption exhibited linear trend and increased with increasing concentration upto 50 mg L-1 after that it decreased with its increasing levels. Freundlich model well fitted and explained the sorption behavior of CP in un-amended as well as amended soil as indicated by the correlation coefficient (R2) values (> 0.90). Both biochar and compost addition significantly increased the sorption potential of the soil. With both amendments sorption capacity increased with increasing level. However, biochar-amended soil showed significantly higher sorption capacities (Kf, 28.68 and 218.83 mg kg-1) for CP compared to compost-amended soils (15.95 and 111.85 mg kg-1) at 0.25 and 0.50%, respectively. Conclusively, above organic amendments have potential to effectively sorb CP and could be used to remediate CP polluted areas by immobilizing CP and ultimately decreasing its bioavailability. [ABSTRACT FROM AUTHOR]

Lemongrass [Cymbopogon citrates (DC) Stapf] is a cosmopolitan economically important grass with a natural potential to adapt to different climates. However, the mechanisms of cross-locational adaptability are not studied in this grass species. To explore some physiological basis of cross-locational adaptability potential of lemongrass, experiments were performed on one population each from Faisalabad and Quetta, Pakistan. Both the population were planted at both the locations in a reciprocal swap arrangement using randomized complete block design with three replicates. The data were recorded on monthly basis from June to December over two consecutive years (2015 and 2016). The swap reciprocated lemongrass populations from Quetta and Faisalabad exhibited differential growth patterns from their native counterparts thus showing flexibility among the populations. Enhanced tillering, root proliferation and increased dry shoot and root weight was observed in the Quetta population adapted in Faisalabad. However, Faisalabad population adapted in Quetta produced taller plants with longer roots, while tillering and number of leaves were greatly reduced in the Quetta adapted population as compared to its counterpart in Faisalabad. Tissue analysis for hydrogen peroxide (H2O2) and malondialdehyde (MDA) data revealed that both the native and adapted populations in Faisalabad accumulated greater H2O2 and MDA in summer months while Quetta population did so in the winter months, thus showing that summer months in Faisalabad and winter months in Quetta to be stressful for the populations in the respective locations. Both native and adapted populations in Quetta displayed dark green leaf color, which was accompanied by increased chlorophyll a and b contents in summer months in Quetta and winter months in Faisalabad, while carotenoids accumulation was greater in the season with high temperature in Faisalabad and chilling temperature in Quetta. Fitting regression equation and finding correlation between maximum and minimum temperatures and relative humidity (RH) revealed negative correlations of temperatures with growth, H2O2 and MDA at both the locations in native and adapted population, while positive correlation of chlorophylls and carotenoids at Quetta and negative ones at Faisalabad, while RH was regressed with none of these attributes (data not shown). This implied that temperature was a major determining factor in the adaptation of populations at either location based on flexibility in physiological adjustments at both the locations. [ABSTRACT FROM AUTHOR]

To develop genotypes that can yield, better under water stress conditions, plant breeders must have knowledge about gene action and combining abilities of parents for various quantitative traits related to drought tolerance. The objective of the study was to provoke genetic information which may be used in cotton breeding program to enhance drought tolerance. Thirty cotton genotypes were screened on the basis of root and shoot length at seedling stage in glasshouse. Ten cotton genotypes namely NIAB-111, CP-15/2, BH-160, CIM-1100, CRIS-134, CIM-446, FH-900, MNH-93, CIM-707 and CIM-482 were declared to be drought tolerant due to overwhelming performance. In contrast, CIM-506, NIAB Karishma, MNH-129, FH-1000, S-12 and Acala-1517C were identified as drought sensitive, later on they were hybridized following Line x Tester mating fashion. Breeding potential of sixty families along with parents was assessed for plant height, monopodial branches per plant, sympodial branches per plant, number of bolls per plant, seed index, uniformity index and excised leaf water loss. Analysis of variance revealed the predominance of non-additive genetic effects in the inheritance of characters studied. The plants selected in early segregating generation may not be dependable, but selection at later segregating generations may show good level of tolerance to water stress. [ABSTRACT FROM AUTHOR]

'Kinnow' mandarin is an important citrus cultivar, which ranks first among all the fruit crops in Pakistan. Being a nonclimacteric fruit, it has low shelflife even in cold storage, may lose its quality because of some physiochemical changes. Wax coating has been proved as an important strategy to maintain the fruit quality under storage. The present study was planned to compare the different types of waxes which include commercial waxes used by the traders and lab. prepared coatings (PHRC wax and benzaldehyde coating) by the scientists of AARI and UAF, respectively. The results revealed that sharine and paraffin wax exhibited minimum fruit rot (2%) with lower weight loss (11.87%) after 90 days of storage and PHRC wax performed statistically at par to commercial waxes regarding weight loss (12%) and fruit rot (3%). The minimum changes in juice weight, TSS/TA ratio, peel/pulp ratio, ascorbic acid and sugar contents were recorded in coated fruits except benzaldehyde coating. Wax coatings also maintained higher levels of total phenolics (240.7 mg GAE 100g-1), antioxidant (63.4%) and enzyme activities of catalase (17.6), peroxidase (0.71), and superoxide dismutase (137.6 U mg-1 protein) during storage. It is concluded that PHRC wax can be recommended for long term storage of citrus fruits as it performed almost at par to commercial waxes and maintained the fruit quality as well as bioactive juice components. [ABSTRACT FROM AUTHOR]

Salinity causes decrease in maize growth and production. Maize occupies an important position in fodder and food crops of Pakistan. Recently, maize has been designated as silicon (Si) accumulator which can alleviate the salinity damage, a major constraint to agricultural crop production. With the objective to combat salinity stress in maize by Si applications using silicic acid Si(OH)4, an experiments was conducted on two contrasting maize genotypes (salt sensitive; Pak-Afgoee and salt tolerant; Ev-5098), under normal and saline conditions. Three different levels of Si (0, 1 and 3 mM) were optimized for salinity tolerance on the basis of plant morphological characters especially dry weight in hydroponics. These Si-level was further used to investigate its effect on maize in hydroponic (0 mM NaCl) and saline (100 mM NaCl). The evaluation was done on the basis of various morphological, physiological, biochemical and growth traits during the experiments. Silicon supplementation into the solution culture significantly improved the K+: Na+ with reduced Na+ and increased K+ uptake. Plant water relations with higher water potential, increase in chlorophyll fractions and its ratios, enhanced stomatal conductance. It was concluded that Ev-5098 is better than Pak-Afgoee under salt stress and silicon inclusion into the any growth medium is beneficial for maize and can improve crop growth by maintaining plant water status, better K+: Na+ and recovering the plant defense system adversely influenced by salt stress. [ABSTRACT FROM AUTHOR]

Studies were conducted to assess the role of mucilage in seed desiccation, germination, and its interaction with fungus in Rough lemon, Sachtion citrumelo and Yuma citrange rootstock seeds of citrus fruits. Water loss percentage was minimum (with or without mucilage) in Rough lemon seeds (20.28%) and (31.25%) at 25°C and 35°C respectively, with high germination percentage (3.33%) while maximum water loss (29.50%) was observed in Sachtion citrumelo at 25°C having low germination percentage (1.33%). However, Yuma citrange showed maximum water loss (34.39%) at 35°C with germination percentage (1.67%). The pathogenic fungus which infected the seeds was isolated, purified and identified as Aspergillus niger. Fungus growth on seeds of Rough lemon, Sachtion citrumelo and Yuma citrange was 14.08 mm, 10.65 mm and 9.36 mm, respectively on 6th day of inoculation. It is obvious from the results that mucilage played significant role in desiccation, germination as well as fungal habitation. [ABSTRACT FROM AUTHOR]

Current water scarcity is an emerging issue in semi-arid regions like Pakistan and cause of deterioration in productivity of crops to reduce crop yield all over the world. Silicon is known to be better against the deleterious effects of drought on plant growth and development. A pot study was conducted to evaluate the effect of Si nutrition (0, 50, 100 and 150 mg/kg) on the growth of a relatively drought tolerant (P-33H25) and sensitive (FH-810) maize hybrids. Two levels of soil water content were used viz. 100 and 60% of field capacity. Water deficit condition in soil significantly reduced morphological and physiological attributes of maize plants. Silicon application significantly improved the plant height, leaf area per plant, primary root length, dry matter of shoot and roots and plant dry matter, water relation and gas exchange characteristics of both maize cultivars under water deficit condition. Poor growth of drought stressed plants was significantly improved with Si application. The silicon fertilized (100 mg/kg) drought stressed plants of hybrid P-33H25 produced maximum (21.68% more) plant dry matter as compared to plants that were not provided with silicon nutrition. Nonetheless, silicon application (150 mg/kg) resulted in maximum increase (26.03%) in plant dry weight of hybrid FH-810 plants that were grown under limited moisture supply i.e., 60% FC. In conclusion silicon application to drought stressed maize plants was better to improve the growth and dry matter could be attributed to improved osmotic adjustment, photosynthetic rate and lowered transpiration. [ABSTRACT FROM AUTHOR]

Soil salinity is a major environmental issue in arid and semiarid regions of the world. Acacia has very important role for salt affected barren lands due to its high salinity tolerance potential. The aim of the present study was to explore the genetic differences among Acacia ampliceps and Acacia nilotica regarding their response to salinity. Three-weeks old seedlings of both species were transplanted in half strength Hoagland nutrient solution having five salt levels (control,100, 200, 300 and 400 mM NaCl) with four replications in completely randomized design with factorial arrangement. After eight weeks of transplantation, the plants were harvested and data for shoot and root length and their fresh and dry weights were recorded. Na+, K+ and Cl-concentration of both root and shoot was determined. All the growth parameters of both species declined significantly in response to salinity. Acacia ampliceps was more salt tolerant than Acacia nilotica with better growth owing to higher K+: Na+ ratio in plant tissues. [ABSTRACT FROM AUTHOR]