Pyramiding of High Grain Weight With Stripe Rust and Leaf Rust Resistance in Elite Indian Wheat Cultivar Using a Combination of Marker Assisted and Phenotypic Selection

Abstract

Wheat (Triticum aestivum L.) is an important cereal crop globally as well as in India and yield improvement programs encounter a strong impediment from ever-evolving rust pathogens. Hence, durable rust resistance is always a priority trait for wheat breeders globally. Grain weight, represented as thousand grain weight (TGW), is the most important yield-contributing trait in wheat. In the present study high TGW has been transferred into two elite Indian wheat cultivars PBW343 and PBW550 from a high TGW genotype, Rye selection 111, selected from local germplasm. In the background of PBW343 and PBW550, an increase in TGW upto 27.34 and 18% was observed, respectively (with respect to recipient parents), through conventional backcross breeding with phenotypic selections in 3 years replicated RBD trials. Resistance to leaf rust and stripe rust has been incorporated in the high TGW version of PBW550 through marker assisted pyramiding of stripe rust resistance gene Yr15 using marker Xuhw302, and a pair of linked leaf rust and stripe rust resistance genes Lr57-Yr40 using marker Ta5DS-2754099_kasp23. Improved versions of PBW550 with increased TGW ranging from 45.0 to 46.2 g (up to a 9% increase) and stacked genes for stripe and leaf rust resistance have been developed. This study serves as proof of utilizing conventional breeding and phenotypic selection combined with modern marker assisted selection in improvement of important wheat cultivars as a symbiont of conventional and moderan techniques.

Meta-QTLs for multiple disease resistance involving three rusts in common wheat (Triticum aestivum L.)

“…A beginning has also been made in using associated markers for MAS for resistance against diseases in several crops including wheat (Kaur et al 2020;Gupta et al 2021;Sharma et al 2021). Examples are also available for achieving MDR against more than one disease, through genes/QTLs or using complex/pleiotropic loci (Table S11).…”

“…In recent years, the pyramiding of genes for resistance against more than one disease has also been facilitated through markers assisted selection (MAS). One good example is the pyramiding of genes for the thousand-grain weight (TGW) along with three rust resistance genes (Yr15 from one source and Lr57-Yr40 from another source) into two popular Indian cultivars, namely PBW343 and PBW550 (Kaur et al 2020).…”

Combining high carotenoid, grain protein content and rust resistance in wheat for food and nutritional security

“…For screening, artificial epiphytotic conditions for rust were created by spraying the urediniospores of Pt pathotypes (100S119, 78S84), and Pt pathotypes (77–1, 77–2, 77–5, 104–2) diluted in water containing Tween-20. For the uniform spread of disease, highly susceptible cultivars HD2967, PBW343, and PBW550 were planted as spreader rows all around the field and after every 20 rows ( Kaur et al, 2020 ). Data was recorded using the Cobb’s scale, as illustrated by Peterson et al, (1948) , when ‘check’ cultivars showed complete susceptibility.…”

“…The selection for the traits i.e., high carotenoid content, high protein content, and resistance to foliar rusts was achieved in a combined phenotypic—genotypic strategy. For the marker-assisted selection, the DNA of F 2 plants was extracted from young leaves using the CTAB method ( Saghai-Maroof et al, 1984 ) with some modifications ( Kaur et al, 2020 ). PsyE1/Lr19/Sr25 was screened using a combination of gene-specific markers i.e., Psy1-E1 specific and Psy1-D1 specific ( Zhang and Dubcovsky 2008 ).…”

Combination of Marker-Assisted Backcross Selection of Yr59 and Phenotypic Selection to Improve Stripe Rust Resistance and Agronomic Performance in Four Elite Wheat Cultivars

“…So far, 83 officially named genes and at least 300 QTL have been reported, and useful molecular markers have been developed for some of them [37,38]. Over 60 of the stripe rust resistance genes or QTL have been intentionally used in wheat breeding [39], for instance, Yr5 and Yr15 combined in several wheat cultivars (reviewed by Wang and Chen 2017), Yr15 and Yr64 by Qie et al [27], Yr15 by Kaur et al [40], Yr26 by Zheng et al [41], Yr48 by Yang et al [42], and QYr.nafu-2BL and QYr.nafu-3BS by Hu et al [43].…”