Sodicity tolerant wheat selections, genomic regions and phenotyping improvement in Western Australia

Document Type

Conference Proceeding

Publication Date


Conference Title

Wheat Breeding Assembly 2022

Place of Publication

Narrabri, NSW


Agricultural Science | Agronomy and Crop Sciences


Dispersive soils due to sodicity and alkalinity adversely affect crop production by its multiple soil constraints like poor soil structure, high pH, accumulation of different salt at toxic levels, soil crusting, waterlogging, etc. Breeding wheat, tolerant to sodicity is often limited by this complex nature of this constraint and difficulties in identifying sources of tolerance due to seasonal variability and high yield per se of the modern cultivars. We researched on phenotyping improvement and genomic exploration. Phenotyping improvement: To identify lines carrying real tolerance, we compared three selection indices namely, simple ratio of yield (REI), ratio of genotypic effects (TI) after excluding site effects, and incremental crop tolerance (ICT) reflected as deviation from regression on two times sowing yield data. We found i) ICT is more efficient than the other two approaches in discriminating the tolerant lines from the intolerant lines, and ii) multiple times sowing data increases its efficiency further. GWAS: To understand the genetics and mechanism of tolerance, we carried out genome-wide association studies (GWAS) on 206 Focused Identification of Germplasm Strategy (FIGS) wheat lines grown for two consecutive years at sodic and non-sodic sites. Among the identified 39 quantitative trait SNPs (QTSs), two QTS were associated with increased yield-ICT by 11.3% and 79.5% on the sodic site. Likewise, two QTS were found to increase the plant establishment-ICT by 24.2% and 37.6%, on sodic soil. Germplasm development: Yield trials of F9 selected lines revealed seven selections outperforming or similar to scepter on sodic sites. These lines can be made available to breeding companies and research organisations.