Identification and Genetic Differentiation of Powdery Mildew Resistance of some Egyptian barley genotypes Using SSRs Markers

Abstract

Powdery mildew is recognized as a paramount disease impacting barley crops, resulting in significant yield losses. This research aimed to identify Egyptian barley genotypes that not only possess a high yield potential but also exhibit resistance to powdery mildew. Twelve barley genotypes were evaluated over two consecutive growing seasons, 2021/2022 and 2022/2023, to assess their disease response. Among these, Line 2 showed the highest resistance to powdery mildew, closely followed by Giza 134, Giza 138, and Line 3, with Line 2 emerging as a promising candidate for breeding programs aimed at developing resistant cultivars. On the other hand, Giza 132 and Giza 126 were identified as the most susceptible, whereas Giza 123 and Giza 2000 displayed moderate susceptibility. The study utilized six SSR primers to analyze genetic diversity among the genotypes, with these primers demonstrating varying of polymorphism percentage, the average being 2.66. Notably, the primer Bmac0213 was identified as the most effective for genetic diversity analysis, with the highest polymorphism percentage (4.28). Molecular similarity indices among the barley genotypes varied, ranging from 0.111 to 0.875, as determined by SSR data analysis. These findings contribute valuable insights for breeding strategies aimed at enhancing powdery mildew resistance in barley, highlighting the role of genetic diversity and molecular markers in identifying and developing resistant cultivars