عنوان مقاله [English]
Alternaria leaf spot caused by Alternaria alternata is one of the most important plant diseases in world. In order to determine genetic diversity, 50 samples were collected from saffron farms of different regions in Razavi Khorasan province (Kashmar, Torbatjam, Torbathaidaryeh, Mahvellat, Bardeskan) and South Khorasan province (Qaen, Saraian, Brjand). A. alternata isolates were isolated with Potato Dextrose Agar media, Molecular test was carried out with a set of five pairs of SSR primers after purification and identification of isolates. A total of 22 alleles were produced by SSR primers with an average of 11.1 alleles in all populations. The highest amounts of alleles were related to locus Mavellat with 14 alleles and lowest of Saraian, Birjand and Qaen with 10 alleles. A Comparison of genetic diversity parameters in eight population showed that Torbatjam population has the highest genetic diversity but lower values were estimated for Qaenat. The highest and lowest genetic distance was detected between Qaen-Mahvellat (0.328) and Bardaskan-Mahvellat (0.054), respectively. Based on dendrogram of populations revealed two distinct groups, one group contained Qaen and the other Birjand, Mavellat, Saraian, Bardaskan, Kashmar, Torbatjam and Torbat hidaryeh. Analysis of molecular variance showed that 71 percent of the genetic diversity belongs to within populations and 29% is located among populations. There was the high genetic similarity between isolates from different regions. Results in this study will be useful in breeding for saffron resistant cultivars and developing necessary control measures.