Introgression of genes associated with yield enhancement and resistance against bacterial leaf blight and blast diseases into an elite rice variety, ‘Jaya’ through marker assisted backcrossing

Abstract

Abstract Background Bacterial leaf blight (BLB) and blast diseases are the major biotic threats responsible for significant yield loss in rice production across all the rice growing regions. Development of high yielding lines along with resistance to major rice disease is more relevant solution for sustainable yields in paddy. ‘Jaya’ the most popular, stable mega rice variety, notified and cultivated in nineteen states across India and is susceptible to bacterial leaf blight and blast diseases and has an average yielding ability (4.5 t/ha). Present study targeting introgression of bacterial leaf blight, blast resistance genes along with yield improvement genes is the most felicitous strategy for a panoramic genetic enhancement to develop high yielding disease resistant rice cultivars. Results In the current investigation, efforts have been made to transfer ‘Xa21’ gene which provide resistance to bacterial leaf blight caused by Xanthomonas oryzae pv oryzae, ‘Pi54’ gene which governs blast resistance caused by Magnoporthe oryzae and yield enhancing gene ‘Gn1a’ which governs the higher grain number per panicle thereby ultimately increasing the yield of the concerned genotype. Using marker assisted backcross breeding approach twenty elite BC2F2 lines with two biotic stress resistance genes (Xa21 and Pi54) and a yield enhancement gene (Gn1a) were developed and evaluated for their disease resistance, yield and agronomic performance under field and controlled condition in BC2F3 generation. The background genome recovery analysis of twenty elite BC2F2 lines was carried out using 1K-RiCA SNP genotyping and it ranged from 85.41 to 96.28 per cent. The selected backcross derived lines showed higher resistant to BLB and blast along with significant yield increase over recurrent parent. Conclusions The strategy of marker assisted backcross selection found to be promising technique in identifying superior backcross introgressed lines. Among the twenty improved backcross derived lines, IJ-4 and IJ-107 were found to be more promising lines by having the highest recurrent parent genome recovery along with increased resistance to BLB and blast with superior yielding ability than recurrent parent Jaya.