Timing of sampling for the canopy temperature depression can be critical for the best differentiation of drought tolerance in chickpea uri icon

abstract

  • Maintenance of water supply during grain filling is criticalfor the drought adaptation of chickpea and thereforemeasurements of canopy temperature depression (CTD)could be used as a proxy for water extraction. Howeverthe conditions and timing of such measurements arenot yet clear. CTD has been recognized as a highlydependable trait for estimating the drought tolerance inchickpea. This study was aimed at identifying an optimalCTD sampling time under drought stress and an optimallyirrigated condition as well. In addition, it also involvedusing 12 selected germplasm accessions to understandthe association of CTD, with the previously establisheddrought response and early rooting characteristics.The growth stage involved identifying a sample whichincluded (i)combination of high genetic variation, (ii) bestdifferentiation of accessions by CTD, (iii) large numberof accessions exhibiting highly negative CTDs, (iv) highheritability of CTD and (v) the best association of CTDwith grain yield. Also, the growth stage was decided tobe the critical time of sampling for canopy temperaturemeasurements. Under drought stress, the critical timingwas 66 days after sowing (DAS) in 2009-10 and 70DAS in 2010-11. Under optimally irrigated condition,the critical timing of sampling was 70 DAS in 2009-10and 63 DAS in 2010-11. But the changes that occurredin the indicative parameters were marginal till 82 DAS,denoting that, in an optimally irrigated environment,a longer window of growth stages was required to bepermitted for sampling. The drought tolerance and localadaptation of chickpea accessions were explained by theCTD under drought stress as well as under optimallyirrigated condition

publication date

  • 2014