Association of canopy temperature depression and membrane relative injury with seed and biological yield in chickpea (Cicer arietinum L.) genotypes under field conditions

Twenty chickpea genotypes were screened for canopy temperature depression (CTD) and membrane relative injury (RI) at flowering, poding and grain-filling stages under natural field conditions at the Nuclear Institute for Food & Agriculture (NIFA), Peshawar, Pakistan in 2020-21 and 2021-22 crop growth seasons. Eight genotypes showed highest averaged CTD values of 4.2-5.5 °C, 3.9-4.8 °C and 4.3-4.8 °C across two seasons at flowering, poding and grain-filling stages, respectively. The same eight genotypes showed lowest average RI values ranging from 24.9-45.5%, 41.2-45.5% and 40.9-48.5% across two seasons at flowering, poding and grain-filling stages, respectively. These genotypes also produced average higher biological yield plant-1 (BYPP) ranging from 59.5 g to 70.4 g and highest seed yield plant-1 (SYPP) of 16.3 g to 20.2 g across 2020-21 and 2021-22. The CTD was significantly (P ≤ 0.01) and positively correlated with BYPP and SYPP with a strong correlation with SYPP (r = 0.9888). The RI had a negative correlation with BYPP and SYPP, being strongly negatively correlated (r = -0.9743) with SYPP. Regression analysis showed positive and negative linear relationship of CTD and RI, respectively, with BYPP and SYPP. A positive association of CTD was found with BYPP and SYPP with a strong association between CTD and SYPP (R2 = 0.977), whereas a strong negative association was found between RI and SYPP (R2 = -0.9489). Based on these results, CTD and RI may be utilized as positive indirect indicators to breed chickpea genotypes for better yield performance under natural environments with variable temperatures.