Introgression of a gene for high grain protein content (Gpc-B1) into two leading cultivars of wheat in Eastern Gangetic Plains of India through marker assisted backcross breeding

A wheat genotype named ‘PBW343+Gpc-B1+LR24’ containing Gpc-B1 gene linked with the DNA-based marker Xucw108, developed at Choudhary Charan Singh University (CCSU), Meerut, through marker-assisted selection, was used as the donor parent to transfer the gene (Gpc-B1) for high grain protein content (GPC) into two popular cultivars (HUW234 and HUW468) of Eastern Gangetic Plains (EGP) of India. In both the cultivars, Gpc-B1 gene was introgressed through marker-assisted backcross breeding (MABB) which involved the following three steps: (i) Foreground selection; (ii) Screening for the carrier chromosome, and (iii) Recovery of recipient parent genome (RPG). Data on GPC (percent grain weight) was recorded for all selected individual plants from BC2F2:3 generation. The dominant marker Xucw108 was used for foreground selection, and heterozygous plants were identified through progeny testing. For RPG recovery, both genotypic and phenotypic selections were used. Introgression of high GPC gene into recipient background without yield loss was completed in 5 years, starting from F1 (2009-10) and completing it in BC2F5 (2013-2014). Ten selected single plants from BC2F3:4 had comparable yield with 26% higher GPC than the recurrent parent HUW 234. For the other parent HUW 468, eight selected plants had comparable yield with 34% higher GPC. Multi-row progenies (BC2F4 and BC2F5) of each selected plant were evaluated for yield traits with donor and recipient parents during 2012-2013 and 2013-2014. Two lines with significantly higher GPC were identified in each of the crosses with no yield penalty. The study reinforced the belief that marker assisted selection (MAS) in combination with phenotypic selection could be a useful strategy for the development of wheat genotypes with high GPC without sacrificing grain yield. Key words: Triticum aestivum, grain protein content (GPC), marker assisted selection (MAS), carrier chromosome, recipient parent genome.