Crown and root rot disease of pistachio seedling caused by Fusarium solani in Kerman province

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Abstract

In order to determine the fungal pathogens associated with seedling decline, a survey was conducted in some pistachio nurseries at Kerman province during spring and summer of 2012. Plants showing different symptoms include of chlorosis, wilting, defoliation, growth reduction and root rot were collected and transferred to the laboratory. Diseased roots were cut into small pieces, disinfected in10% NaOCl, plated onto Potato Dextrose Agar (PDA) and incubated at 25°C. Totally 81 fungal isolates were isolated from seedlings showing diseased symptoms which F. solani and Rhizoctonia solani with 46 (56.79% of total isolates) and 3 isolates (3.71 % of total isolates) had highest and lowest numbers of isolates respectively. Two isolates of F. solani were used in the pathogenicity trial. Pathogenicity test was conducted on pistachio seedling cvs. “Badami”, “Sarakhs” and “Qazvini” under greenhouse conditions. The experimental design was arranged in factorial based a completely randomized design (CRD) with three treatments and four replications. The soil of pots was infected with 50 g kg-1 of inoculum (fungus colonised wheat seeds: sterilized sand, 50:50) and non-infested soils were used as control. Plant growth parameters include of shoot length and number of leaves and disease index were measured 2 months after inoculation. Data were analyzed by SAS software and Duncan's multiple range test was used for means comparison. According to the results obtained in the pathogenicity tests, “Qazvini” and “Badami” considered as resistant and susceptible cultivars respectively. The inoculated fungus, F. solani, was re-isolated and identified from inoculated plants to confirm pathogenicity test.

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