Evaluation of Genetic Diversity and Zinc Deficiency Stress Tolerance in Spring Wheat Cultivars

Like other crops, wheat also faces several environmental limitations during its growth period, such as the lack of micronutrients. Zinc deficiency causes limitations in crop production, especially growth, and yield in calcareous soils. Considering the economic and agricultural importance of wheat in the world and Iran, it is necessary to pay attention to and identify genetic relationships, to know the level of genetic diversity, and estimate it in wheat germplasm by plant breeders. The present research was conducted with the aim of identifying genetic diversity and investigating stress tolerance indicators on phenological, physiological, and biochemical traits in desirable spring wheat cultivars under optimal conditions and zinc deficiency stress.

Sixty-four spring wheat cultivars under both optimal conditions and zinc deficiency stress, a simple lattice design was performed in 2019-2020 in the research farm of the Faculty of Agriculture, Urmia University. In this research, phenological traits including the number of days to germination, number of days to booting, number of days to pollination, number of days to physiological maturity, grain filling period, and physiological and biochemical characteristics including canopy temperature, total chlorophyll, leaf area index, fresh weight and dry weight, relative water content, grain protein concentration, zinc concentration in shoot and grain yield were measured.

The results of the analysis of variance revealed a significant difference among the cultivars in both optimal conditions and zinc deficiency stress in most of the studied traits. positive and significant correlations of Ys and Yp with MP, GMP, STI, and HM indices showed that these indices are the most suitable indices for screening cultivars under zinc deficiency stress conditions.

Generally, based on studied traits, tolerance indices, the results of principal components analysis, and cluster analysis, Aflak, Darya, Arvand, Roshan, Kavir, and Sirvand were selected as desirable cultivars and VEE/NAC, Tajan, Parsi, and Panjamo were identified as undesirable and susceptible cultivars. The selected tolerant and susceptible cultivars can be used for developing biparental populations, gene expression analysis, and breeding programs to produce cultivars with high yield.