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Wheat is a major staple food of world. Heat stress has emerged as a major problem in wheat with detrimental effects on overall growth (vegetative and reproductive phases), yield and quality of grains. There exists wide variability for various physiological traits across the wheat genotypes that can contribute or confer tolerance to heat stress. In this context, so far little attention has been paid on ear and ear-related traits for their role in imparting yield stability and heat tolerance in wheat. Present study was therefore done to assess the contribution of ear and awns to the yield in wheat under heat stress condition. Twenty-nine wheat genotypes with variability in ear characteristics were selected and subjected to heat stress by late sowing (15 December). Results revealed huge variability across the wheat genotypes for the contribution made to the main ear grain yield by the main ear itself (1.9% in MP 4010 to 45.7% in HD 3059) and by the awns (− 12.2% in SOKOLU to 30.1% in CUS/79/PRULA). Negative values as recorded for contribution made by awns [SOKOLU (− 12.2%), MP 4010 (− 8.56%) and HUW (− 8.48%)] indicated that in these genotypes, awns served as sink rather than source. Derived parameter i.e., contribution made by main ear without awns ranged from − 18.0 (Kundan) to 37.5% (NP 4). Overall, the study revealed a huge genotypic variability for the contribution (viaphotosynthesis) made by main ear and its components (awns and spikelets). Genotypes were ranked and contrasting ones were identified. Presence of awns and their length emerged as beneficial trait under terminal heat stress. Intra-ear competition was noticed and thereby this study proposed the concept of “awns with optimum length and physiological performance”. In future, ear-related traits and the genotypes identified can be utilized in breeding of wheat for thermo-tolerance under diverse environments. Work in the direction to decipher physiological and biochemical bases of ear-related traits, including the awns, will not only provide better understanding but also decipher the possible mechanism/s that impart thermo-tolerance in wheat.

The present study was conducted to evaluate the role of traits associated with photosynthesis, Radiation interception (RI) and Radiation Use Efficiency (RUE) in relation to biomass and yield in Basmati rice genotypes. It was hypothesized that, whether yield improvement of Basmati rice will depend on enhancing the biomass through better RI and RUE or harvest index or both. A field experiment was conducted with nineteen aromatic rice genotypes, which included eighteen Basmati and one aromatic hybrid (PRH-10). Among the nineteen genotypes there was variability in biomass production and leaf area and the biomass production was linearly correlated with total intercepted PAR (TIPAR) between 55 and 95 DAS. Higher radiation interception was associated with the variability in crop growth rate among the genotypes. There was a high variability in the RUE ranging from (1.46–2.89 g MJ−1), and those genotypes maintained higher crop growth rate (CGR). Genotypes with higher LAI were associated with a lower extinction coefficient (k) and improved RUE. However, the leaf photosynthetic parameters viz. photosynthesis rate, transpiration rate and stomatal conductance were negatively associated with the aboveground biomass at anthesis. The net assimilation rate (NAR) was positively correlated with the photosynthetic parameters. Comparison of the mean of five highest biomass Basmati genotypes (HBBG), namely PB 1121, Sarbati, Pant Basmati-1, PB 1728 and PB1718 was done with the aromatic rice hybrid PRH-10. At anthesis stage, there was not much difference in dry weight, CGR and in RUE in HBBG compared to PRH-10. At harvest, the HBBG showed higher biomass (+ 15%) compared to PRH-10. However, the grain yield was higher in PRH-10 (+ 8%) due to its higher harvest index (+ 25%) over HBBGs. It was associated with higher number of spikelets per panicle (+ 19.5%) and % filled spikelets (+ 7.5%). Moreover, less height in PRH-10 compared to HBBG also favoured higher harvest index. The better yield performance of PRH-10 could be associated with photosynthetic parameters—higher flag leaf area (+ 40%) and higher flag leaf photosynthesis (+ 48%). It may have contributed in supporting the higher sink demand leading to high yield in PRH-10. Therefore, it can be concluded from the present study that high biomass Basmati genotypes which have high RUE in combination with higher sink capacity (i.e., number of spikelets/panicles) and better partitioning due to reduced height can lead to yield enhancement in Basmati rice.

Tomato (Solanum lycopersicumL.) fruits of nine popular varieties in India were analysed for change in the levels of different nutrients (P, K, Fe, Zn, B, Cu, Mg, Ca and Mn) during the period of their postharvest ripening (fruits harvested at green mature stage and stored at 25 ± 1 °C). This work is in continuation of our previous and related work wherein similar studies were done on the tomato fruits undergoing ripening while attached to the plant (Ramesh in 1–15, 2020). Here in this study, nutrients were estimated in the outer pericarp of tomato fruits at the time of their harvest (at green mature stage) and during the storage period at 5, 10 and 14 days after harvest (DAH). Under above said storage conditions, ripening behaviour of tomato fruits of different varieties was also determined by ripening index (RI %) at 3, 5, 8, 10 and 14 DAH. The results on nutrients showed net increase in P, K, Fe, Zn, B and Cu with static levels for Mg, Ca, and Mn at 14 DAH in comparison to their levels at green mature stage. The increase is explained in view of remobilization of nutrients from other parts of the fruit to the outer pericarp. While, internal mobilization of nutrients within the fruit might have helped in maintaining the static level of nutrients. Correlation analyses revealed that lower content of K and Ca along with higher content of B and Cu can impart slow ripening to tomato fruits. Comparison between plant-attached (our earlier study) and plant-detached tomato fruits (this study) indicated that in contrast to the fruits at green mature stage there is net increase in Zn, B, Cu, Mg, Ca and Mn in the outer pericarp of plant-detached ripened fruits. This was due to the internal mobilization of nutrients within the fruits towards the outer pericarp and absence of any remobilization or back flow of nutrients away from the fruits as the fruits were off the plant.

Anatomical features of mango (Mangifera indicaL.) fruits were examined at three different maturity stages in four varieties namely; Langra (L), Amrapali (A), Dushehari (D) and Ramkela (R) which differ in their rate of ripening. Gross anatomical variations were observed among the varieties in terms of cuticle thickness, number of cellular layers in hypodermis, compactness of hypodermal region and pattern of staining of exocarp region representing lignin and suberin depositions on cell walls. At cellular level, significant differences were observed in cell density which was primarily due to variations in cell size rather than the extent of intercellular spaces. The varietal differences in cell density was more prominent in the mesocarp region compared to the peel region of the mango fruits. The rate of ripening of fruits was in order of L > A > D > R and was found to be directly related to the cell density. While the respiration rate was in order of L > D ≈ A > R and this was inversely related with the cell size (L ≈ D < A < R). Fruits of variety Langra with smallest cell size and highest rate of respiration showed fastest rate of ripening. In contrast to this, fruits of variety Ramkela having the largest cell size and lowest rate of respiration showed slowest rate of ripening. The results indicated that the cell size is inversely linked to the rate of ripening due to its influence on the rate of respiration. This association between the cell size and the rate of respiration is explained on the basis of positive relationship between surface to volume ratio of cells and the respiration rate or basal metabolic rate in tissues/organs. The study pointed out the role of fruit anatomy in varietal differences which is having implications on respiration rate and on ripening.