Assessment of salinity tolerance and SSR profile differentiation in nine maize genotypes (Zea mays L)

The low productivity of maize in Iraq is resulting from many factors that relate to insufficient knowledge of the genetic sources of germplasm used for crop improvement. A major goal of this project was to find the phenotypic, and genotypic variations by using salinity stress and Simple sequence repeat markers among nine maize genotypes. Genetic variation for salt tolerance was assessed in nine maize genotypes using four salinity levels (control, 50, 100, and 150 mM NaCl). Seedling of each genotype was compared to their growth under control and saline conditions. Salt stress (sodium chloride) markedly reduced the germination percentage, shoot and root lengths and fresh and dry masses. However, Dhqan, Fajr 265, Talar were considered as tolerant genotypes while Medium 791 defined as sensitive genotype. Genotypic analysis was carried out using 18 SSR primers. A total of 46 polymorphic alleles were perceived among the maize genotypes with a range of 1-7 polymorphic bands were detected with size ranging from (90 to 500 bp) along the different maize genotypes. Polymorphism information content, marker index and gene diversity ranged from 0.178 to 0.788, 8.900 to 68.800, and 0.198 to 0.815, respectively. Dendrograms were constructed based on total microsatellite polymorphism, and nine genotypes were grouped into three major clusters. The analysis of molecular variance results revealed 17 and 83% of the total variation between and within populations (local and Iranian). The results confirmed the efficiency of SSR (Simple Sequence Repeat) markers in the detection of genetic variation among maize genotypes.