Relationship of photosynthesis and related traits to seed yield in oilseed Brassicas

The physiological basis of yield in oilseeds Brassicas needs to be investigated, and the contribution of these traits to its yield is difficult to decipher. Eight cultivars of Brassica belonging to 3 species viz. B. juncea, B. napus and B. carinata - based on significant differences in yield were tested over two years. Net photosynthesis, transpiration, stomatal conductance and water use efficiency were investigated on 3rd and 4th fully expanded leaf on the main stem and related to yield. Average photosynthetic efficiency (umolm-2s-1) was higher in RLC1 (36.1), GSC6(36.3) and PC5 (33.8) cultivars. Impact of environment was inconspicuous. However interactions (GxY) were significant for the studied photosynthetic traits except Pn. Lower transpiration rates were associated with higher water use efficiency in RLC1 (5.69), GSL1 (5.44) and GSC6 (5.40). Positive correlation between SY and Pn (0.385) was recorded for the first time in Brassicas although the magnitude of association was low. Quality mustard cultivar (RLC1, B. juncea) and amongst B. napus GSC6 (canola) and Hyola PAC401 (hybrid, canola) were higher yielders due to relative high Pn, more efficient utilization of water and chlorophyll content. Indeterminate growth habits of the cultivars indicated highest contribution to Pn by leaves during flowering as compared with early siliquae formation. Environment had a profound impact on the yielding ability and the photosynthetic traits

Electrolyte Flocculation of Haemoglobin-stabilized Toluene/Water Emulsion

958-96

Understanding consumer adoption of mobile payment in India: Extending Meta-UTAUT model with personal innovativeness, anxiety, trust, and grievance redressal

YesMobile payments are the future as we move towards a cashless society. In some markets, cash is already being replaced by digital transactions, but consumers of many developing countries are slower in transition towards digital payments. This study aims to identify major determinants of consumer mobile payment adoption in India the country with second largest mobile subscribers in the world. Existing mobile payments adoption studies have predominantly utilised Technology Acceptance Model (TAM), which was primarily developed in organisational context and criticised for having deterministic approach without much consideration for users’ individual characteristics. Therefore, this study adapted meta-UTAUT model with individual difference variable attitude as core construct and extended the model with consumer related constructs such as personal innovativeness, anxiety, trust, and grievance redressal. Empirical examination of the model among 491 Indian consumers revealed performance expectancy, intention to use, and grievance redressal as significant positive predictor of consumer use behaviour towards mobile payment. Moreover, intention to use was significantly influenced by attitude, social influence, and facilitating conditions. The major contribution of this study includes re-affirming the central role of attitude in consumer adoption studies and examining usage behaviour in contrast to most existing studies, which examine only behavioural intention

Terminal heat stress in Indian mustard (Brassica juncea L.): Variation in dry matter accumulation, stem reserve mobilization, carbohydrates translocation and their correlation with seed yield

The rapeseed mustard is one of the most important sources of edible oil in India and contributes 28.6% in total oilseed production. The mustard growing areas in India are experiencing the vast diversity in the agro climatic conditions. Here, we studied forty-nine advanced breeding lines of Brassica juncea L. for two consecutive years (2016-18) to examine the variations in the remobilization of assimilates from flowering to maturity stage and their contribution to seed filling under stressed environment. Further, we investigated the impact of high temperature on dry matter accumulation and partitioning from source to sink in Brassica germplasm. The synchronization between the seed filling stage and the onset of heat spell is critical event that determines the overall yield. Imbalances caused due to miss-matching of above events created hindrance in source-sink translocation, thus resulted in yield losses. Amount of remobilized dry matter, remobilization efficiency and remobilization percentage increased significantly, while the dry matter accumulation, total carbohydrates content and seed yield per plant declined in the late sown genotypes during both crop seasons. Reduced accumulation of photo assimilates under stress and higher sink demand resulted in more number of shriveled seeds leading to yield depression. The higher remobilization efficiency in late sown genotypes was strongly associated with dry matter at flowering that consequently tended to affect the final seed weight. This study will provide insights for better understanding of source-sink relationships in Indian mustard under heat stress and the differential remobilization efficiencies in the advanced breeding lines

Terminal heat stress in Indian mustard (Brassica juncea L.): Variation in dry matter accumulation, stem reserve mobilization, carbohydrates translocation and their correlation with seed yield

423-431The rapeseed mustard is one of the most important sources of edible oil in India and contributes 28.6% in total oilseed production. The mustard growing areas in India are experiencing the vast diversity in the agro climatic conditions. Here, we studied forty-nine advanced breeding lines of Brassica juncea L. for two consecutive years (2016-18) to examine the variations in the remobilization of assimilates from flowering to maturity stage and their contribution to seed filling under stressed environment. Further, we investigated the impact of high temperature on dry matter accumulation and partitioning from source to sink in Brassica germplasm. The synchronization between the seed filling stage and the onset of heat spell is critical event that determines the overall yield. Imbalances caused due to miss-matching of above events created hindrance in source-sink translocation, thus resulted in yield losses. Amount of remobilized dry matter, remobilization efficiency and remobilization percentage increased significantly, while the dry matter accumulation, total carbohydrates content and seed yield per plant declined in the late sown genotypes during both crop seasons. Reduced accumulation of photo assimilates under stress and higher sink demand resulted in more number of shriveled seeds leading to yield depression. The higher remobilization efficiency in late sown genotypes was strongly associated with dry matter at flowering that consequently tended to affect the final seed weight. This study will provide insights for better understanding of source-sink relationships in Indian mustard under heat stress and the differential remobilization efficiencies in the advanced breeding lines

Microstructural and metabolic variations induced by Bipolaris oryzae inciting brown spot disease of rice

Brown spot disease, caused by Bipolaris oryzae, is a dominant lethal rice disease that causes qualitative and quantitative crop damage. The current study sought to identify various histological and metabolic changes that occur during brown spot development in susceptible rice plants. We present a conceptual framework that shows B. oryzae suppresses the production of immune-related metabolites in a susceptible cultivar, PR 124 using a comparative metabolomics approach. Un-inoculated rice leaves have an epidermis followed by cortex parenchyma with large intercellular spaces, and no fungal hyphae or distortion were found. Following pathogen inoculation, fungus hyphae grow intercellularly in photosynthetic areas and intracellularly in the bundle sheath, resulting in the microcracks on the surface of the rice leaf. Cellular depositions could have produced the clogging, which disrupted water channels and induced distortion of vascular bundles, ultimately leading to cellular collapse and the withering of rice plants under field conditions. Silica on an infected leaf surface suggests a more robust defence response, thus providing some degree of endurance at the later stages of infection. A significant decline in the total chlorophyll and lignin content was observed in the inoculated leaves compared to the un-inoculated ones. Higher relative injury was recorded post-inoculation. Early oxidative responses like malondialdehyde, proline and hydrogen peroxide accumulation occurred in the flag leaves at various intervals after inoculation. Reduced salicylic acid, phenol and lignin content post-inoculation could be attributed to lowered phenylalanine ammonia lyase activity. Significant declines in the activities of catalase, peroxidase, chitinase and glucanase suggest that immune suppression by this biotrophic pathogen impacts specialised plant metabolism. Thus, these findings form the basis for additional studies focussed on the characterisation of metabolic components involved in pathogen perception during the early stages of intracellular signal transduction

Effect of elevated temperature on phenology, growth, yield components and seed yield of Brassica juncea grown in temperature gradient tunnels (TGT)

Elevated temperature is one of the major production constraints of Indian mustard. The present study was aimed to estimate variations in phenology, yield attributes and seed yield under elevated temperature (ET) in temperature gradient tunnels (TGT) and open field for heat tolerance. Fourteen genotypes consisting of introgression lines and the mustard varieties were sown in TGT and open field for two consecutive winter seasons (2017-2019).The phenophases were shortened due to elevated temperature in TGT as compared to control except physiological maturity which was trailed by 17-18 days during both the years. Temperature affect was most severe on siliqua formation and seed filling. Among growth parameters only length of main shoot suffered reduction whereas yield contributing parameters like siliqua on main shoot, siliquae plant-1, seeds siliqua-1 and 1000 seed weight along with biomass, seed yield and  harvest index suffered significant decline in TGT. Average temperature had positive correlation with all phenological parameters except flowering completion, growth parameters except number of primary and secondary branches while yield attributes only with 1000 seed weight, biomass and seed yield under TGT. Interestingly, number of primary branches had significant negative correlation with average temperature under both control (r=-0.59*) and TGT (-0.61*). Phenological traits had strong relationship with seed yield under TGT. However, seed yield had strong relationship with growth parameters, yield attributes under control except for number of primary branches. Biomass had strong relationship with seed yield under both TGT (R2= 0.51) and control (R2= 0.43). Two years testing revealed introgression lines (JA24 and JA53) and varieties (JD6 and Giriraj) tolerant to heat stress