مرگ ناگهانی سویا در اثر Fusarium redolens در کرمان

Soybean, (Glycine max) is one of the most important oil seeds in the world. Multiple Fusarium species have been isolated from soybean plants causing root rot, wilting and sudden death syndrome worldwide. Sudden death of soybean plants exhibiting necrotic root lesions and characteristic foliar symptoms that were observed toward the flowering or pod-development stages as chlorotic and mottling, on the upper leaves were reported fron research greenhouse of Kerman Graduate University of Advanced Technology in July of 2017. Different parts of the plants were washed, surface disinfected, rinsed in deionised water and cultured on PDA. Fusarium isolated were recovered from root and shoot sections. Culture morphology on PDA were flat with yellow pigmentaion. Macroconidia on CLA medium were abundant having a hooked apical cell, foot shaped basal cell and with 3-5 septa. Microconidia on SNA medium monophialide, oval to cylindrical with 0-1 septa. Based on morphological characteristics as well as sequence data from translation elongation factor (EF1-α) gene the isolated were identified as Fusarium redolens. One isolate was tested for pathogenecity on soybeen. Root inoculation of 2-week-old seedlings with colonized oat kernals with a single spore isolate caused similar root and foliare symptoms on soybean plants in the greenhouse whereas control plants did not exhibit the symptoms. Isolations were made from roots of inoculated and control plants Fusarium species were not isolated from control plants. To our knowledge, this is the first report of F. redolens causing sudden death of soybean in Iran, however, this species may ahve been misidentified as F. oxysporum previously since the two are morphologically similar.