Combination of empirical and trait-based approaches for breeding drought tolerance ingroundnut (Arachis hypogaea L.) uri icon

abstract

  • Breeding groundnut varieties that combine improved pod yieldunder water-deficit stress, and enhanced water use efficiency(WUE) is an important strategy to overcome the challengesin water-limited conditions. SPAD chlorophyll meter reading(SCMR) and specific leaf area (SLA) are the two important traitsassociated with WUE. SCMR is simple, non-destructive and robustmethod. Maintaining high chlorophyll density under waterstress conditions is associated with high WUE in groundnut, andSCMR measures green colour intensity associated with chlorophylldensity. A RIL population (280) was evaluated during2015/16 under well-watered (WW) and water-deficit stress(WS) for yield parameters and SCMR. Pod yield is independentof SCMR (R2=0.003), suggesting the importance of simultaneousselection for both these traits in breeding programs. Forbreeding varieties suitable for water-stress conditions, measuringboth pod yield under stress and WUE through its surrogateSCMR are useful. In Africa and Asia, groundnut is largelya rainfed crop. The frequency of drought is variable, and everyyear is not a drought year. Therefore, the commercial groundnutvarieties should perform well under normal rainfall years,and have less yield penalty during drought years. The approachof measuring pod yield penalty under water-deficit stress comparedto WW condition is a useful selection criterion in breedingprograms, wherein the lines with minimum yield penalty areselected. Such a selection criteria enable selection of genotypesthat perform well under normal seasons and have less yield penaltyduring drought seasons. In this paper, we discuss progressin groundnut breeding at ICRISAT using these two approaches

publication date

  • 2017