شناسایی قارچ‌های همراه با بیماری لکه برگی نخل خرما ( Phoenix dactylifera L.) در استان خوزستان

Date palm (Phoenix dactylifera L.) is one of the most important sources of income for many farmers and palm farmers in Khuzestan province, with an area under cultivation of about 40 thousand hectares of fertile palm trees and with the production of about 200 thousand tons of date products per year. Leaf spot disease is one of the important fungal diseases of date palm that severely reduces the yield of this product. The purpose of this study was to identify the fungi that cause leaf spot disease in the groves of Khuzestan province, which is the first key step to manage and control the disease. Infected date palms were observed in the date producing areas of Abadan, Ahvaz, Behbahan, Khoramshahr, Shadgan, Darkhoin, Hoizeh and Mahshahr located in Khuzestan province. A total of 158 infected leaf samples were collected and after being transferred to the laboratory with 90-degree alcohol, they were surface disinfected and then cultivated on potato dextrose-agar (PDA) medium. After a week, fungal isolates appeared, and after their purification by single spore and hypha tip method, they were kept at refrigerator temperature (4◦C) for molecular analysis. The pathogenicity test was carried out on the leaves of the Barhi date palm. The isolates were identified using morphological and molecular characteristics. (tef) and β-tubulin regions were amplified and sequenced by polymerase chain reaction (PCR). Molecular based identification using multigene sequences showed that the isolates belonged to Alternaria alternata, A.bursii, Curvularia subpapendorfii, Fusarium prolifratum and Nigrospora lacticolonia and most of the isolates belonged to Alternaria genus.