Marker assisted improvement for leaf rust and moisture deficit stress tolerance in wheat variety HD3086

Abstract

There is a significant yield reduction in the wheat crop as a result of different biotic and abiotic stresses, and changing climate, among them moisture deficit stress and leaf rust are the major ones affecting wheat worldwide. HD3086 is a high-yielding wheat variety that has been released for commercial cultivation under timely sown irrigated conditions in the Indo-Gangetic plains of India. Variety HD3086 provides a good, stable yield, and it is the choice of millions of farmers in India. It becomes susceptible to the most prevalent pathotypes 77-5 and 77-9 of Puccinia triticina (causing leaf rust) in the production environment and its potential yield cannot be realized under moisture deficit stress. The present study demonstrates the use of a marker-assisted back cross breeding approach to the successful transfer of leaf rust resistance gene Lr24 and QTLs linked to moisture deficit stress tolerance in the background of HD3086. The genotype HI1500 was used as a donor parent that possesses leaf rust-resistant gene Lr24, which confers resistance against the major pathotypes found in the production environment. It possesses inbuilt tolerance under abiotic stresses with superior quality traits. Foreground selection for gene Lr24 and moisture deficit stress tolerance QTLs linked to Canopy temperature (CT), Normal Differential Vegetation Index (NDVI) and Thousand Kernel Weight (TKW) in different generations of the backcrossing and selection. In BC2F2, foreground selection was carried out to identify homozygous lines based on the linked markers and were advanced following pedigree based phenotypic selection. The selected lines were evaluated against P. triticina pathotypes 77-5 and 77-9 under controlled conditions. Recurrent parent recovery of the selected lines ranged from 78-94%. The identified lines were evaluated for their tolerance to moisture stress under field conditions and their resistance to rust under artificial epiphytotic conditions for two years. In BC2F5 generation, eight positive lines for marker alleles were selected which showed resistance to leaf rust and recorded an improvement in component traits of moisture deficit stress tolerance such as CT, NDVI, TKW and yield compared to the recurrent parent HD3086. The derived line is named HD3471 and is nominated for national trials for testing and further release for commercial cultivation.

Accelerating Genetic Gain for Key Traits Using Genome-Wide Association Studies and Genomic Selection: Promising Breeding Tools for Sustainable Agriculture

“…Through the combination of phenotypic selection and marker-assisted background selection, the genome of the recurrent parent HD3086 recovered more quickly and to a greater extent compared to the estimated average recovery percentage. It has been observed in previous research that two backcrosses with selection for RPP were sufficient for better genome recovery in important cereal crops like wheat (Xu et al, 2017;Sharma et al, 2021;Mallick et al, 2022;Sunilkumar et al, 2022), rice (Ellur et al, 2016;Grover et al, 2020), and maize Zunjare et al, 2018). In our study, two drought-tolerant improved lines, HD3086-7- , had maximum recovery rates of 92% and 90%, respectively.…”

“…MAS has been utilized frequently in bread wheat for the introgression of traits, including disease resistance and quality enhancement (Kumar et al, 2010;Malik et al, 2015;Shah et al, 2017;Sharma et al, 2021). However, a small number of studies have previously transferred QTLs for promising wheat varieties to increase drought tolerance and yield under moisture deficiency conditions (Merchuk-Ovnat et al, 2016;Rai et al, 2018;Gautam et al, 2020;Todkar et al, 2020;Sunilkumar et al, 2022). Wheat variety HD3086 is the choice of millions of farmers in Indo-Gangetic plains; its potential yield is reduced under restricted irrigation (RI) conditions.…”

Genetic dissection of marker trait associations for grain micro-nutrients and thousand grain weight under heat and drought stress conditions in wheat

“…It is necessary to have a deep knowledge of the genomic region influencing grain iron and zinc content under drought and heat stress in order to develop specific varieties with a high micronutrient status along with a higher yield. Previously identified drought- and its component trait-related QTLs were utilized to improve drought tolerance of varieties through marker-assisted back crossbreeding ( Sunilkumar et al., 2022 ). For such implications, the identification of a marker linked with the trait of interest is a prerequisite.…”

QTL mapping: insights into genomic regions governing component traits of yield under combined heat and drought stress in wheat

“…By contrast, HI1500 is a widely accepted wheat variety recommended for cultivation under restricted irrigation conditions in the parts of the central zone in India. This variety possesses valuable attributes associated with resistance to drought and heat stress (Sunilkumar et al, 2022). blocks, with four checks utilized in the study.…”