Groundnut or peanut (Arachis hypogaea L.), an annual legume, is an
important oil, food, fodder and feed crop grown in more than 100 countries. Heat and
drought stress, and their combination are important abiotic constraints of groundnut
production in Asia and Africa, which together accounts over 90% of global groundnut
area. An increase in mean air temperature of 2-3 °C is predicted to reduce groundnut
yields in India by 23-36% as heat stress during critical stages affects the pod yield.
Moreover, heat stress worsens the burden of moisture stress aggravating the pod yield
losses. Although groundnut genotypes continue to produce photosynthates under heat
stress, only tolerant genotypes possibly have coping mechanisms to partition
photosynthates to pods. Understanding the physiological, biochemical, molecular and
genetic mechanism of heat-stress tolerance in groundnut is useful to devise breeding
strategies to improve adaptation to heat stress. Intense phenotyping of plants grown in
the field and glasshouses distinguishes sensitive and tolerant genotypes for heat stress,
and to study the associated physiological and morphological differences between such
genotypes. This chapter elaborates on the effects of heat stress on different life stages
in groundnut, mechanisms contributing to adaptation to heat stress and recent
developments in phenotyping, genetics and genomic tools to improve adaptation to
heat stress.
Keywords: Climate change, Genetics, Groundnut, Heat stress, Mapping,
Phenotyping.
