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The present investigation was carried out to understand the genetic variability, association, cause and effect relationships between yield and its attributing agronomic and physiological traits in 23 F3 families of pre-breeding restorer germplasm in a hybrid rice program for six agronomic and three physiological characters. The variability and heritability parameters were grouped under the high category for the number of productive tillers per plant, leaf area per plant, dry matter production and single plant yield. The traits viz., the number of tillers per plant and panicle length, leaf area per plant and dry matter production showed a direct correlation with single plant yield and in cause and effect relationships. All traits had a direct influence on single plant yield except days to 50% flowering and chlorophyll index. At the intra-family level, six families namely 30, 35, 36, 46, 55 and 82 showed high variability and heritability values of all parameters for six traits. All nine traits exhibited normal distribution. [ABSTRACT FROM AUTHOR]

Pulses are one of the important food crops due to higher protein content. Among the pulses, greengram (Vigna radiataL.) is popular and major grain legume used for consumption since ancient days. Elevated temperature stress during critical crop growth stages affects yield in greengram and lead to very low productivity Worldwide. Hence, it is essential to study the responses of critical growth stages of greengram under elevated temperature stress. With this background, the present investigation was carried out in CO 8 variety of greengram to study the physiological characters and yield responses of greengram under different elevated temperature stress conditions. The experiment was conducted in the open top chambers located in the Department of Crop Physiology, Tamil Nadu Agriculture University, Coimbatore during 2016-2017. Elevated temperature stress was given two levels, by raising the temperature up to 2°C and 4°C from the ambient temperature. Plants subjected to an elevated temperature at various stages viz., vegetative, flowering and pod development. Observations on various physiological parameters viz., leaf area, gas exchange parameters like photosynthetic rate, stomatal conductance, transpiration rate, leaf temperature were recorded. Also, osmotic potential and osmotic adjustments were studied under stress period. The response of yield was also recorded under different elevated temperature stress. Among the growth stages, the flowering stage was more critical to the elevated temperature and the impact of 4°C raise from ambient temperature was higher when compared with the elevated temperature of 2°C. [ABSTRACT FROM AUTHOR]

Abiotic stress seriously affect the productivity of legumes worldwide. Among legumes, greengram is very popular and extensively grown in India, however, the production is affected by hostile environments, especially heat stress due to climate change. The global air temperature is predicted to rise by 0.2°C per decade, which will lead to (1.8-4.0°C) higher temperature than the current level by 2100. In the above view, an experiment was conducted in CO 8 green gram by elevating the temperature up to 2°C and 4°C from ambient level to study the effect of elevated temperature on morpho-physiological, biochemical and yield attributes of greengram during different growth stages. The results revealed that when CO 8 greengram exposed to elevated temperature of 4°C from the ambient, showed higher variation in its growth, development and yield attributes when compared with 2°C raise. The impact was lesser when plants subjected to an elevated temperature of 2°C from ambient when compared to 4°C raise. This study helps us to know the response of green gram to different elevated temperature at various crop growth stages. Thus, the present investigation opened new vistas in the field of developmental physiology for identifying the heat tolerant genotypes in greengram. [ABSTRACT FROM AUTHOR]