Characterization of wheat genotypes for stay green and physiological traits by principal component analysis under drought condition

Abstract

An experiment was conducted to examine the magnitude of genetic diversity and characters contributing to genetic\rdiversity among 35 core elite wheat germplasm from INDIA and CIMMYT under water deficit condition. Principal components\r(PC) analysis showed that three components explained 67.73 per cent of the total variation among traits. The first PC contribute\r38.8 per cent, second PC contribute 17.17 per cent and third PC contribute 11.66 per cent of total variation between traits. The first\rPC was more related to LSR, DSI, SCMR, RWC, ear weight per plant, harvest index and grain yield. The second PC was more\rrelated to plant height, LSR, tillers per plant, biological yield, thousand kernel weight and RWC. Therefore, selection based on first\rcomponent is helpful for a good hybridization breeding program. Genetic divergence was carried out and grouped genotypes into\rsix genetically distinct clusters. Cluster II genotypes viz., CHIRYA7, HW2041 and PBW502 shows superiority for functional stay\rgreen trait by exhibiting low cluster mean for leaf and DSI, and high cluster mean for SCMR, photosynthetic rate, RWC, tillers per\rplant, ear weight, 1000 kernel weight, biological yield, harvest Index, grain yield per plant and in contrast Cluster IV genotypes are\rnon-stay green and drought susceptible by exhibiting high cluster mean for LSR and DSI. A three dimensional (3D Plot) depicts\rmaximum genetic divergence between HW2041 and CBW38 and CHIRYA7 and HW2033. Stay green trait and all yield attributing\rtraits except plant height can be improved by intermating HW2041 with CBW38 and CHIRYA7 with HW2033 genotypes which\rresult in a highly heterotic hybrid for these traits under water deficit stress in wheat.