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Background: In the current climate change scenario, high temperature stress is one of the major constraints limiting the yield of blackgram severely. The increasing global temperature is targeting the yield of blackgram by causing severe reproductive failures. In order to combat this problem, it is important and inevitable to screen blackgram genotypes that can withstand to high temperature and produce better yield even under adverse climatic conditions. Keeping this in view, the present investigation was carried out. Methods: Hundred blackgram genotypes were subjected to Temperature induction response technique, in which lethal temperature was standardized as 54°C for 3 hours and optimum induction temperature as 36-46°C. The selected genotypes from temperature induction response technique were further evaluated for biochemical traits using hierarchial clustering and principal component analysis. Result: The cellular level tolerance was assessed in blackgram genotypes using standardized lethal and optimum induction temperature. Based on the percent reduction in the seedling growth of induced over control and survival percentage, 27 blackgram genotypes were categorized as highly tolerant, 54 genotypes as moderately tolerant and 19 genotypes as susceptible. Biochemical characters such as antioxidant defence activity, lipid peroxidation and free radicals were analyzed in TIR induced 27 thermotolerant and 3 susceptible genotypes. The results indicated that all the traits such as total seedling length and antioxidant defence enzymes except malondialdehyde and free radicals showed a prominent increase under heat stress. Based on hierarchial clustering, 30 genotypes were clustered as 5 groups: tolerant (cluster-3,4), moderately tolerant (cluster-1,2) and susceptible (cluster-5). Principal component analysis showed that first five components showed 75.8% of total variation in control, whereas 63.3% of the total variance was covered by the first two PCs in heat induced conditions. The information generated from the study would help the breeders in developing heat tolerant varieties that perform better even under extreme high temperatures. [ABSTRACT FROM AUTHOR]

The physicochemical characteristics and shelf life of mango[Mangifera indica L.] fruits treated with calcium chloride (CaCl2-1%, 2%), calcium nitrate (Ca(NO3)2-1%, 2%),potassium nitrate (KNO3-1%, 2%) and carboxyl methyl cellulose(CMC - 0.5, 1%) were studied. Untreated fruits served as the control. All tested treatments indicated a significant delay in the change of weight loss(16.84%), ripening(51.66%),decaying percentage(46.66) and retained firmness(3.23 kg/cm2) of fruits and biochemical qualities viz., total soluble solids(22.33Brix), sugar accumulation (18.17%) and tritratable acidity on 16th day in mango fruits compared to control. The significant (5%) impact of treatment is found on the least decay percentage in the order of fruits treated with calcium nitrate (2%) followed by 1% Ca(NO3)2, 2% CaCl2 and 1% CaCl2. Hence, it could be concluded that post harvest chemical treatment with calcium nitrate, calcium chloride (1%, 2%) has the potential to control spoilage, prolong the storage life and preserve valuable attributes of post harvest quality of mango, presumably because of its effect on inhibition of ripening and senescence processes by lowering the respiration rate. [ABSTRACT FROM AUTHOR]

Sunflower Hybrid (KBSH-1) was cultivated in Open Top Chambers (OTCs) at ambient (380 ppm) and elevated CO2 (550 and 700ppm) conditions. Biomass accumulation in root, stem, head and seed was significantly greater at elevated CO2 (550 ppm and 700ppm) compared with ambient (380 ppm).The improvement in total biomass with 550 and 700 ppm CO2was 18.7 per cent and 40.5 percent and seed yield was 21.0 per cent and 45.9 per cent respectively compared to ambient. The positive growth response to increased atmospheric CO2 resulted in N and C concentrations. Although elevated CO2 levels tended to lower N concentration in some plant parts compared to ambient, elevated CO2 enhanced total N accumulation in each plant component via an increase in biomass.Elevated CO2 decreased the N per cent compared to ambient in seed meal, leaf and stem. At the recommended dose of nutrients, the total N uptake was high in plants grown at 700 ppm (1.25 g per plant), followed by 550 ppm (1.11g per plant) and ambient (0.96 11 g per plant). At the recommended dose of nutrients, physiological N use efficiency (PE) and grain N use efficiency (NUEg) was also high in plants grown at elevated CO2 in OTCs and nitrogen harvest index (NHI) was similar for ambient (70.3%) and elevated CO2 conditions (70.4 and 70.2 per cent at 550 ppm and 700 ppm).The total carbon accumulation was high in plants grown at 700 ppm, followed by 550 ppm and ambient.The C/N ratio of plants was high at elevated CO2 conditions being 21.2, 20.0 and 19.0 at 700, 550ppm and ambient control respectively. [ABSTRACT FROM AUTHOR]

Groundnut (Arachis hypogaea L.) is an important oilseed cash crop and an erratic rainfall with prolonged dry spells during critical pheno-phases of reproductive stages affects its yield. A field trial was carried out with groundnut genotypes- JL- 24, ICGV 91114, Narayani, Abhaya, Dharani and Greeshma to study the variability in morphological, biochemical and yield traits to moisture stress at flowering stage. Significant reduction in growth and yield components of all the selected groundnut genotypes was observed due to moisture stress. ANOVA for pod weight, seed weight, 100 seed weight, harvest index, total biomass were found to be highly significant (p<0.01) for genotypes, moisture levels and their interactions. Impact of moisture stress on plant height, leaf area, leaf and shoot biomass was lowest in Dharani and osmoprotectant- proline and activity of antioxidant enzymes- SOD and POD were higher in Dharani. The yield performance of Narayani, Abhaya, Dharani were similar as well as superior under control condition where as under moisture stress conditions Dharani recorded highest seed yield, HI with lowest reduction in seed number and 100 seed weight. Under control conditions seed yield had significant positive correlation with pod number, pod weight and seed number whereas under moisture stress conditions with SOD, POD, leaf area, leaf dry weight, pod weight, seed number, 100 seed weight and shelling %. The groundnut genotype Dharani performed best under both control and moisture stress conditions as its high antioxidative enzyme activity and proline content might have been ameliorated the ill effects of moisture stress. [ABSTRACT FROM AUTHOR]

Effect of different CO2 concentrations on sucrose metabolizing enzymes and on carbohydrate metabolism was studied for eight blackgram (Vigna mungo L. Hepper) genotypes grown in open top chambers under ambient (380 μmol mol-1) vs. elevated CO2 (550 and 700 μmol mol-1) levels. The higher acid invertase activity over neutral invertase indicated the major role of acid invertase in sucrose breakdown. Higher acid invertase activity over Sucrose Synthase (SuSy) suggested the major role of invertase in sucrose breakdown and sucrolysis. Sucrose Phosphate Synthase (SPS) activity did not match with sucrose pool sizes in mature leaves and rather varied among genotypes. Plants exposed to higher CO2 concentrations showed higher starch and sucrose contents as compared with those exposed to ambient CO2. Leaf starch content being found several-folds higher than sucrose throughout the study indicated its major role in regulating assimilate partitioning. Increase in glucose vs. fructose concentrations for genotypes grown under elevated CO2 conditions ranged from 20 to 90% and from 10 to 140%, respectively. The hexoses/sucrose ratio for elevated CO2 concentration was approximately 0.8-1.6, however for ambient CO2 content it approximately amounted to unity. Genotypes IC436720, IC519805, IC343952, and IC282009 with low hexose/sucrose ratio representing high CO2 assimilation along with high sucrose formation indicated better tolerance to elevated CO2 for carbon partitioning and carbohydrate metabolism. The up-regulation of leaf carbohydrate metabolizing enzymes of low hexose/sucrose as well as low sucrose/starch ratios for the genotype IC436720 (as compared with other genotypes) improved its photosynthetic capability which coupled with its better efficiency of carbon partitioning (indicative of better acclimation to elevated CO2) could prove beneficial to its growth and productivity in the future change of climatic conditions. [ABSTRACT FROM AUTHOR]