Epidemiological aspects of bean decline disease caused by Fusarium species and evaluation of the bean resistant cultivars to disease in Northwest Iran
The national project of Iran aimed to study the etiology of bean decline disease and the induction of bean resistant cultivars to the disease. Samples of 75 infected bean plants (300 in total) were collected from four growing locations in three provinces of Northwest Iran. The isolated pathogens were Fusarium solani (41.6%), Fusarium oxysporum (32%), Fusarium sambucinum Fuckel (18%), Rhizoctinia solani (5.4%) and Pythium debaryanum (2.7%). Sufficient inoculums of three Fusarium species were prepared in chaff medium and added to the natural field soil to obtain 2000 cfu g1/soil of each species in treated soils. Ten local and international bean cultivars (Emerson, Dehghan, Joules, Akhtar, Naz, Sayad, Golden, Keshavarz, Daneshkadeh and Soheir L- 90) were sown into 50 infested and 50 non-infested pots; then their growth and yield productions were evaluated. ‘Naz’ was the most resistant cultivar, which produced the highest dry matter yield (175 g /15 plants) and the lowest yield reduction (9.3%), while ‘Joules’ had moderate production (110 g/15 plants) and loss (31.7%), and ‘Soheir L-90’ showed the highest susceptibility with the lowest (60 g/15 plants) and highest yield loss (52%). Thus, the results show the most important bean cultivar resistant to Fusarium decline disease, which is significant in favor of yield productions.
Key words: Bean, decline, resistance, Fusarium