Marker-assisted forward and backcross breeding for improvement of elite Indian rice variety Naveen for multiple biotic and abiotic stress tolerance

Abstract

The elite Indian rice variety, Naveen is highly susceptible to major biotic and abiotic stresses such as blast, bacterial blight (BB), gall midge (GM) and drought which limit its productivity in rainfed areas. In the present study, a combined approach of marker-assisted forward (MAFB) and back cross (MABC) breeding was followed to introgress three major genes, viz., Pi9 for blast, Xa21 for bacterial blight (BB), and Gm8 for gall midge (GM) and three major QTLs, viz., qDTY1.1, qDTY2.2 and qDTY4.1 conferring increased yield under drought in the background of Naveen. At each stage of advancement, gene-based/linked markers were used for the foreground selection of biotic and abiotic stress tolerant genes/QTLs. Intensive phenotype-based selections were performed in the field for identification of lines with high level of resistance against blast, BB, GM and drought tolerance without yield penalty under non-stress situation. A set of 8 MAFB lines and 12 MABC lines with 3 to 6 genes/QTLs and possessing resistance/tolerance against biotic stresses and reproductive stage drought stress with better yield performance compared to Naveen were developed. Lines developed through combined MAFB and MABC performed better than lines developed only through MAFB. This study exemplifies the utility of the combined approach of marker-assisted forward and backcrosses breeding for targeted improvement of multiple biotic and abiotic stress resistance in the background of popular mega varieties.

QTLs and Genes for Salt Stress Tolerance: A Journey from Seed to Seed Continued

“…In their investigation, proteome profiling for tolerant lines confirmed gene colocalization in the salinity tolerance QTL intervals mapped in the RIL population [ 57 ]. Rahman et al screened RILs derived from IR29/Hasawi and identified eight hotspots conferring salinity tolerance across environments colocalised on chromosomes 1, 4, 6, 8, and 12 [ 83 , 133 ].…”

Superior haplotypes towards the development of blast and bacterial blight-resistant rice

“…Consequently, the urgent need to breed rice varieties with enhanced resistance has been recognized ( Khush, 2005 ). Recently, several resistant genes against blast and BLB have been utilized in breeding programs to improve both elite rice varieties and parental lines of hybrids through Marker-Assisted Selection (MAS) ( Dixit et al., 2020 ; Singh et al., 2022 ; Janaki Ramayya et al., 2021 ). However, deploying a single resistance gene often leads to rapid breakdowns.…”

Optimizing quantitative trait loci introgression in elite rice germplasms: Comparing methods and population sizes to develop new recipients via stochastic simulations

“…A key limitation in the ability of breeding programmes to leverage these benefits of major‐gene marker‐assisted selection is the availability of those genes in an appropriate elite germplasm (Janaki Ramayya et al, 2021; Wu et al, 2014). Studies on current breeding programmes have shown that about half of the genes and QTLs that could be useful are not found in current elite material; a further 15% or so are present at very low frequency (Cobb, Juma, et al, 2019; Juma et al, 2021).…”