Identification of microsatellite markers associated with genomic regions controlling yield and pheno-physiological traits in bread wheat accessions and cultivars under different moisture conditions

IntroductionWheat is one of the most stable crop in the world, and drought stress is one of the major environmental factors that reduce agricultural products. Evaluation of genetic diversity in plant breeding program is the main basis for development and achieving self-sufficiency in the agricultural product. The objective of this experiment was to investigate the association between microsatellite markers and genomic regions controlling yield, physiological, and phenological traits in 23 accessions and two cultivars of bread wheat, as well as to evaluate the genetic diversity of the studied population in term of yield, physiological and phenological traits, and microsatellite markers under rainfed and irrigation conditions.Materials and methodsA field experiment was carried out in a randomized complete block design with three replications under rainfed and irrigation conditions in the research field of Razi University, Kermanshah, Iran, in 2016-2017. Grain yield, 15 physiological traits and six phenological traits were measured. Twenty microsatellite markers were used for molecular evaluation of the studied genotypes. Genomic DNA was extracted as bulk from 2-3 weeks old seedlings by modified CTAB method. To determine the quality and quantity of the extracted DNA, electrophoresis on 0.8% agarose gel was used. Finally, the association between microsatellite markers, yield, physiological and phenological traits in rainfed and irrigated conditions was calculated using stepwise regression analysis by SPSS23 software.Research findingsAnalysis of variance showed that there was a significant difference between the accessions for most of the traits studied. Sixteen out of twenty markers had detectable polymorphisms. The XCFD168-2D, XGWM350-7D and XGWM136-1A primers were the most suitable primers for subsequent studies. Association analysis by stepwise regression showed that in rainfed and irrigation conditions, markers XGWM350 (a3) and XGWM334 (a1) were common for physiological traits and markers XGWM642 (a1), XGWM350 (a1), and XCFD168 (a1) were common for phenological traits. The XGWM410 (a1) marker on yield, physiological and phenological traits in both conditions; XGWM265 (a1) marker on yield and physiological traits in irrigation conditions and phenological traits in both conditions; XGWM124 (a2) marker on yield and some physiological traits in rainfed conditions and phenological traits in both conditions; XGWM165 (a1) marker on physiological and phenological traits in rainfed conditions, and XGWM577 (a2) markers on grain yield and physiological traits in irrigation conditions and some phenological traits in rainfed conditions were jointly related. In addition, the most positive markers in rainfed conditions are related to the trait of rate of filing seed, and in irrigated conditions, respectively, they are related to grain yield, water use efficiency, rate of filing seed, relative water content, and days to physiological maturity traits.ConclusionAccording to the evaluation of the genetic diversity of primers XCFD168-2D, XGWM350-7D and XGWM136-1A, the most suitable primers for wheat were introduced in subsequent studies. Based on the association analysis, most of the markers produced by the primers used in this research had a high significant associated with the studied traits, and by using these primers, which have the ability to reproduce informative loci, plants can be screened at the seedling stage. Furthermore, The microsatellite primers linked to traits are suggested in marker assisted selection breeding programs to identify suitable parents for constructing mapping populations and producing new varieties.