Breeding Mechanisms for High Temperature Tolerance in Crop Plants

Abstract

Increase in global warming poses a severe threat on agricultural production thereby affecting food security. A drastic reduction in yield at elevated temperature is a resultant of several agro-morphological, physiological and biochemical modifications in plants. Heat tolerance is a complex mechanism under polygenic inheritance. Development of tolerant genotypes suited to heat extremes will be more advantageous to tropical and sub tropical regimes. A clear understanding on heat tolerance mechanism is needed for bringing trait based improvement in a crop species. Heat tolerance is often correlated with undesirable traits which limits the economic yield. In addition, high environmental interactions coupled with poor phenotyping techniques limit the progress of breeding programme. Recent advances in molecular technique led to precise introgression of thermo-tolerant genes into elite genetic background which has been reviewed briefly in this chapter.

Improvement of heat stress tolerance in soybean (Glycine max L), by using conventional and molecular tools

“…Breeding programs were carried out in heat stress areas that endorse crop selection for thermo-tolerant traits. Understanding the genetic and physiological-based heat tolerance mechanisms will help to develop heat tolerant cultivars suitable for sustainable growth under heat waves ( Shanmugavel et al, 2020 ). Alsajri et al (2019) screened 64 soybean cultivars using certain morphological and physiological traits for heat stress tolerance.…”

“…Under heat stress conditions, the plant adopts various mechanisms like short-term escape and avoidance, changed leaf orientation, membrane lipid functions, cooling, early maturity, and so on for survival ( Shanmugavel et al, 2020 ). The plant also shows different degrees of leaf rolling under heat stress ( Sarieva et al, 2010 ).…”

“Salicylic acid enhances thermotolerance and antioxidant defense in Trigonella foenum graecum L. under heat stress”

“…Heat stress's negative effects can be mitigated by developing thermo-tolerant plants employing a variety of physiological and genetic techniques. Accordingly, a detailed insight of mechanisms of heat tolerance, physiological reactions of plants to high temperatures, and potential approaches for enhancing crop productivity under stress conditions is crucial [ [12] , [13] , [14] , [15] , [16] ]. Under high temperatures, several physiological as well as biochemical mechanisms are activated in plants which are imperative to get through stress [ 17 ].…”

Transcriptomic analysis of thermotolerant Artemia franciscana populations shows that thermal adaptation affects expression and regulation of metabolism-, stress-, and immune-related genes

“…Several studies on selective breeding for ITT (SITT) have been published for aquatic animals, ruminants 10 , sheep 11 , pigs 12 , and crops 13,14 . Hence, genetic selection may be a cost-effective tool for improving thermotolerance and disease tolerance in animals 15,16 .…”