Introgression of terminal drought stress tolerance in advance lines of popular pearl millet hybrid through molecular breeding

Abstract

HHB 226 is a popular pearl millet hybrid of northern India and terminal drought stress is a major factor limiting its yield potential. Genetic improvement is one of the most effective strategies to develop improved versions of farmer-preferred varieties of crop plants. The present study was undertaken to improve terminal drought tolerance in pearl millet hybrid HHB 226 by introgressing, drought tolerance QTLs from 863 B to the male parent HBL 11 of the hybrid. Marker-assisted foreground selection was undertaken using four polymorphic SSR primers present on linkage group 2 and 5 to identify plants possessing alleles for resistance in the segregating population (BC4F2) along with stringent phenotypic selection for faster recovery of the recurrent parent genome. Background selection using 32 polymorphic SSR markers spanning on seven linkage groups were used to estimate the recovery of recurrent parent genome in improved lines. A maximum of 82% of recurrent parent genome was recovered in selected plants. The plants with drought tolerance QTLs and higher recurrent parent genome were selfed to raise BC4F3. Morpho-physiological analysis of BC4F3 lines under non-irrigated conditions showed that the QTL introgressed lines had higher yield than both the parents. Molecular marker and morpho-physiological analysis showed that line number MBB 58 has highest recovery of recurrent parent genome and performed well in comparison to original HBL 11. The improved versions of HBL 11 can be crossed with ICMA 843-22 to develop improved HHB 226.