Genotypic and environmental differences in grain contents of Zn, Fe, Mn and Cu and how they relate to wheat yield

Grain content of micronutrients is crucial for wheat growth and dietetic health. High grain contents of micronutrients are beneficial to enhancing nutritional functions of grains and guaranteeing security of crop products. By using acid digestion and atomic absorption spectrophotometry, Zn, Fe, Mn and Cu contents were measured in the grains of 17 wheat varieties from 5 different regions in Henan Province. Genotypic and environmental differences in Zn, Fe, Mn and Cu contents in gains and their relation to yield characteristics were also analyzed. The study shows that grain contents of Zn, Fe, Mn and Cu are 38.39±12.57 μg·g^-1, 79.13±49.45 μg·g^-1, 35.24±11.72 μg·g^-1, and 4.84±0.78 μg·g^-1, respectively. The variation coefficient of grain Fe content is the highest and that of Cu is the lowest. Analysis of variance shows that the effects of genotype, environment and genotype/environment interaction (GEI) are significant (P<0.01). Whereas wheat grain content of Zn, Mn and Cu is largely influenced by environment, that of Fe is mainly driven by GEI. Varietal stability of grain micronutrient content was also analyzed using the Eberhart and Russell model. The analysis indicates that varieties, whose micronutrients contents are insensitive to environment, have lower grain micronutrient content and vice versa. Among the 17 varieties, “Pu99084” has the highest environmental stability. Correlation analysis shows a positive genetic correlation between micronutrient and protein contents. There is a negative genetic correlation between micronutrient content and 1000-grain weight. However, phenotypic correlation between micronutrient content and grain yield is positive. There exists the possibility for simultaneously improving grain contents of micronutrients, protein and yield.