بازنگری بر عوامل بیماریزای قارچی ریشه چغندرقند در کرج و تعیین مهمترین بیماری منطقه

The aim of this study was to reidentify the most prominant pathogen to sugarbeet rots during 1998 growing season in karaj. samples were collected from four main localities as: kamal abad, meshkin abad, nazar abad, and shahriyar diseased seedling samples resulted almost isolation of Pythium and Fusarium while sampling toward end of the growing season and harvesting time asumed Rhizoctonia isolates. in this study 74 fungal isolates from five genera were collected. after that according to their colony appearance were grouped to five groups and then from each group two were used for the pathogenicity tests following their standard manner. they were identified as: Rhizoctonia saloni (AG-4) Which contained 43/25% of total isolates and indicated most important pathogen of karaj sugarbeet fields. fusarium spp. also shared 25/75% of total isolates, Pythium ultimum and P.aphanidermatum both were 20/35% and finallly Mucor circinelloides together with Rhizopus stolonifer contained 10/65% of totally collected isolates. The two fungi: P.ultimum and M.circinelloides seem to be new sugarbeet root rot pathogens for Iran.

Keywords:

قارچ ریشه , چغندرقند , کرج , پوسیدگی ریشه , کمال آباد , مشکین آباد , نظر آباد , شهریار , قارچ ‭Fusarium , ‬قارچ ‭Pythium , ‬قارچ ‭Rhizoctonia‬