Saffron Agronomy and Technology

Abstract 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.

Abstract Saffron (Crocus sativus L.) is the most important plant in the world that has been used in cooking, confectionery and drug productions because of the color and aromatic substances in its sigma. Corm rot disease is one of the most important diseases in Iran. For identification of causal agents, wild saffron plants with wilt symptoms and rot lesions on corm were randomly collected in different regions of Ivan and Mehran in the Ilam province. Diseased samples were surface sterilized by dipping into domestic bleach solution (5% NaOCl). Then they were washed three times with sterile distilled water, dried with sterile filter paper and plated on potato dextrose agar (PDA). Samples were incubated for three days in an incubator at 20°C. A total of eight Fusarium isolates were obtained and purified using the single spore method. Fusarium oxysporium isolates were identified according to their morphological and microscopic characteristics as described by the identification key. The pathogenicity of Fusarium oxysporium isolates were artificially tested in the greenhouse on a wild susceptible cultivar according to Koch’s principles.