Candidate genes controlling alkaline-saline tolerance in two different growing stages of wheat life cycle

Abstract

BackgroundAlkaline-saline (AS) stress threats crop development and productivity. Understanding the genetic control of AS tolerance in wheat is important to produce wheat cultivars that outstand such a severe stress condition.MethodsA set of 48 cultivars were tested under controlled and AS stress conditions at seedling and maturity stages. The effect of AS on seedlings and kernel traits was measured to select tolerant and high-yielding genotypes. Single-marker-analysis (SMA) and gene enrichment were conducted to understand the genetic control of AS tolerance in both growth stages.ResultsAS stress decreased all kernel traits and most of the seedling traits. High correlations were found between the studied traits in each growth stage. The correlation between the traits related to both stages was non-significant. SMA identified a total of 292 and 52 markers significantly associated with the studied traits under controlled and AS stress conditions. Seven and 20 gene models were identified to control AS tolerance in each stage. Gene enrichment analysis identified one and six networks that control AS tolerance. Four genotypes were selected as superior genotypes.ConclusionThe genetic control of the studied traits differs under control and AS conditions. Two genetic systems control AS tolerance in each growth stage. This study is the first one that unlocked the genetic control of AS tolerance in seedling and mature growth stages and identified the biological process that lead to this tolerance. Four genotypes were selected for crossing in future breeding programs to improve AS tolerance in spring wheat.