Unlocking genetic insights: Evaluating wheat RILs for physiobiochemical traits under terminal heat stress conditions.

BACKGROUND: The increasing impacts of heat stress on wheat production due to climate change has entailed the development of heat-resilient crop varieties. To address this, two hundred recombinant inbred lines (RILs) derived from a cross between WH711/WH1021 were evaluated in a randomized block design (RBD) with two replications at CCSHAU, Hisar, during 2018-19 under heat stress and non-stress conditions. Heat stress was induced by altering the date of sowing so that the grain filling stage coincide with heat stress. RESULTS: Heat stress adversely affects RILs performance, as illustrated by alterations in phenotypic traits. Highest coefficients of variations were recorded for TAA, CTD 1, WUE, CTD 2, Cc and A under non-stress and heat stress conditions whereas gs, WUEi and GY under non-stress and SPAD 1, SPAD 2, GY and NDVI 2 under heat-stress conditions recorded moderate estimates of coefficient of variations. CTD 2, TAA, E, WUE and A displayed a significant occurrence of both high heritability and substantial genetic advance under non-stress. Similarly, CTD 2, NDVI 2, A, WUEi, SPAD 2, gs, E, Ci, MDA and WUE exhibited high heritability with high genetic advance under heat-stress conditions. CONCLUSIONS: Complementary and duplicate types of interactions with number of controlling genes were observed for different parameters depending on the traits and environments. RILs 41, 42, 59, 74, 75, 180 and 194 were categorized as heat tolerant RILs. Selection preferably for NDVI 1, RWC, TAA, A, E and WUEi to accumulate heat tolerance favorable alleles in the selected RILs is suggested for development of heat resilient genotypes for sustainable crop improvement. The results showed that traits such as such as NDVI, RWC, TAA, A, E, and WUEi, can be effective for developing heat-resilient wheat genotypes and ensuring sustainable crop improvement.

Phenotypic, Physiological and Biochemical Delineation of Wheat Genotypes Under Different Stress Conditions.

Wheat is a vital crop, providing calories, nutrients and versatility in the food industry. However, the combination of heat and drought stress, exacerbated by climate change, poses a significant threat to wheat production, leading to potential yield losses. To ensure the sustainability of wheat production it is crucial to prioritize research on developing stress-tolerant wheat genotypes. The current study focused on identifying the traits that are important for developing stress-tolerant wheat varieties under timely sown irrigated, drought stress, heat stress, and combined stress conditions. It addresses the knowledge gap regarding the combined effects of heat and drought stress on wheat physiology and yield, aiming to shed light on the intricate interactions between these stresses. The experiment was conducted at CCS HAU, Hisar, during the Rabi seasons of 2019-2020 and 2020-2021. By evaluating variability parameters, conducting correlation analysis, and path coefficient analysis among 80 diverse wheat genotypes, this research identifies genetic factors contributing to stress tolerance and helps select plants with desirable characteristics. The results showed that traits i.e., malendialdehyde, wax covering on blade, wax covering on sheath and wax covering on spike had high potential for improvement through selection among genotypes for grain yield and its component traits. The study also highlighted the importance of selecting wheat varieties with early maturity to mitigate the risk of yield loss under combined stress conditions. Moreover, the interaction between drought and heat stress can increase oxidative stress, leading to elevated malondialdehyde levels. Selecting varieties with lower malondialdehyde and optimal canopy temperature is important. Understanding the complex response of wheat to heat, drought, and their combined stress is essential for improving crop quality and production potential. Overall, this research contributes to the field of plant breeding by facilitating the development of wheat varieties with high and stable yields in challenging environments.

Green revolution to genome revolution: driving better resilient crops against environmental instability.

Crop improvement programmes began with traditional breeding practices since the inception of agriculture. Farmers and plant breeders continue to use these strategies for crop improvement due to their broad application in modifying crop genetic compositions. Nonetheless, conventional breeding has significant downsides in regard to effort and time. Crop productivity seems to be hitting a plateau as a consequence of environmental issues and the scarcity of agricultural land. Therefore, continuous pursuit of advancement in crop improvement is essential. Recent technical innovations have resulted in a revolutionary shift in the pattern of breeding methods, leaning further towards molecular approaches. Among the promising approaches, marker-assisted selection, QTL mapping, omics-assisted breeding, genome-wide association studies and genome editing have lately gained prominence. Several governments have progressively relaxed their restrictions relating to genome editing. The present review highlights the evolutionary and revolutionary approaches that have been utilized for crop improvement in a bid to produce climate-resilient crops observing the consequence of climate change. Additionally, it will contribute to the comprehension of plant breeding succession so far. Investing in advanced sequencing technologies and bioinformatics will deepen our understanding of genetic variations and their functional implications, contributing to breakthroughs in crop improvement and biodiversity conservation.