الكشف عن أنواع الجنس فيوزاريوم قسم لاسيولا المسببة لمرض تعفن حبوب الذرة الصفراء

الملخص EN

This study has been carried out to detect Fusarium sction liseola specie which were associated with maize seeds ,determine their percentage of existence and test their pathogenicity.

The results of isolation and identification of fungi from seed in six fields and stores in Baghdad, Babylon and Wasit governorates showed that there were 15 species of fungi associated with seeds, the identification of five species belong to section liseola (F.nygami, Fproliferatum ,F.subglutinans ,F.thapsinum and F.

verticillioides) were considered the first record on maize seeds in Iraq.

The existence of these species in samples was variable, F.proliferatum and F.verticillioides were the most frequently encountered with frequency percentage of 28 and 54% respectively.

Preliminary test to detect the pathogenic isolates of Fusarium species(F.culmorum ,F.nygami, Fproliferatum ,F.subglutinans ,Fthapsinum and F.

verticillioides)by soaking injured and un injured seeds in spore suspension of 20 isolates of Fusarium showed that all tested isolates significantly reduced seed germination compared with control treatment.

The isolates were different in their pathogenicity, F.proliferatum (FPH20)and F.

verticillioides (FVH19) isolates showed the highest percentage of reduction in injured and uninjured seeds Results of treatment of pot soils with spore suspension of ten pathogenic Fusarium species isolates under glasshouse conditions showed that all the isolates significant reduction in percentage of germinated seeds and in shoot and root length and dry weight of maize seedlings compared with control treatment.

The two isolates of F.verticilloides (FVH19) and F.proliferatum (FPH20) were the most virulent.