شناسایی، بیماریزایی و تعیین پراکنش عوامل بیماری پژمردگی فوزاریومی سیب زمینی

In order to determine and identification species of Fusarium pathogens involving potato wilt and their distribution area in Ardebil, Tehran, Semnan, Hamedan and Hormozgan provinces, during 2002- 2003, infected potato specimens were collected. Fusarium selective media was used to isolate Fusarium species from the plant samples. Isolates were identified based on morphological and microscopic characters with Gerlach and Nelson Fusarium keys. Pathogenicity testes were carried out under greenhouse conditions using sterilized soil artificially infested with wheat seed inoculums. Number of fields in each region based on potato cultivation area assigned and disease distribution and infection severity were determined in these places. Results of this study showed that, the disease had a widespread occurrence throughout the provinces. Isolates were recovered from various parts of providences, based on morphological and microscopic characters; the following Fusarium species were identified: F. oxysporum, F. solani, F. equiseti, F. acominatum and F. sambucinum. Pathogenicity testes were carried out under greenhouse conditions using sterilized soil artificially infested with wheat seed inoculums. Results indicated that F. solani and F. oxysporum were recovered from all areas. The disease was distributed in 75-100% of Ardebil areas and on the average 10% of potato plants were involved. In Shahrood, 15-70% of fields were infected and 10-50% of plants were contaminated. Fusarium wilt was distributed in 80-100 per cent of Tehran (Absard and Firuzkoh) areas and 8-10% plants were infected. Hamedan areas (Razan, Asadabad, Kabodarahang, Hamedan and Bahar) were contaminated 40-90% and 3-25% of plants were infected in fields. Hajiabad and Hashtbandy in Hormozgan province were infected middlingly, 60% to potato wilt and level of infection was 10-15% in these areas. Keywords: Fusarium, Pathogenicity, Ardebil, Tehran, Semnan, Hamedan and Hormozgan.

Keywords:

بیماری زا , پراکنش بیماری , پژمردگی فوزاریومی , سیب زمینی