Title : Analysis of genetic variation of grain yield, iron and zinc contents using phenotype and SSR markers in landraces and commercial bread wheat cultivars
Evaluation of genetic variation and the interrelationship of grain yield and micronutrients accommodate development of verities for improvement of the malnutrition in human diets. The current study was performed to investigate the genetic diversity in 42 bread wheat genotypes, including 17 commercial cultivars, 10 landraces, 12 Swiss lines and 3 Afghan genotypes for grain yield and iron and zinc contents. The experiment was conducted at the research station of School of Agriculture, Shiraz University, Bajgah, Shiraz, Iran over two growing seasons. The amount of iron and zinc was quantified using atomic absorption instrument and DTZ (Dithizone) staining method. The results of analysis of variance and mean comparison revealed that wheat genotypes differed in grain yield, iron and zinc contents. Estimation of heritability showed that the contribution of genetic variance in traits expression was higher than environmental component. Grain yield was negatively correlated with iron content whereas its correlation with zinc content was positive. The correlation coefficients between records of iron and zinc by atomic absorption and DTZ staining methods were significant. Several accessions consisting of KC4551, KC4848, KC2165, KC4542, S-B120, S-B12, S-B86 and S-B79 had the highest amount of iron. Among genotypes, KC4863, S-B122, KC4551, S-B126, Camedo, Madavi and KC4633 accumulated higher zinc content. The polymorphism information content (PIC) index was calculated for the tested simple sequence repeat (SSR) markers. The mean PIC was 0.75 whereas it was 0.74, 0.76, 0.82 and 0.70 for Xuhw89, Xgwm154, Xgwm192 and Xgwm538 markers, respectively. The analysis of the main coordinates for SSR markers (Xuhw89, Xgwm154, Xgwm192 and Xgwm538) associated with iron and zinc contents demonstrated that Xgwm192 was able to differentiate the high and low iron and zin genotypes. The analysis of molecular variance (AMOVA) demonstrated significant genetic variation within (60%) and between (40%) populations of the studied genotypes. Overall, our results indicated that sufficient genetic variation was available in the plant materials tested and that the SSR markers were efficient in discriminating varieties for micronutrients in wheat.
What will audience learn from your presentation?
- Large variations were found among the wheat cultivars for grain yield, grain iron, and zinc, showing the remarkable potential for improving grain yields and grain iron and zinc concentrations.
- The lines with high Fe and Zn can be used as hybrid parents and may also help in further genetic investigations.