مهار زیستی پوسیدگی ریزوکتونیایی ریشه لوبیا توسط برخی از گونه‎هایTrichoderma در شهرستان الیگودرز

Common bean (Phaseolus vulgaris L.) is one of the most important economic crops which is attacked by serious diseases such as Rhizoctonia root rot. One of the ways to management this disease is biological control using Trichoderma species. Aim of this study was to assess the ability of different species of Trichoderma to control bean root rot disease caused by Rhizoctonia solani and also their ability to promoting the growth of bean plants. In this study, the antagonistic ability of eight different species of Trichoderma against the plant pathogenic fungus R. solani isolated from the bean fields of Aligudarz county was investigated in vitro using methods dual culture, production of volatile and non-volatile compounds as well as in vivo. The results showed that mycelial growth inhibition of R. solani by Trichoderma species ranged from 23/92% -50/71% in dual culture, T. longibrachiatum (LT35) species showed the highest impact on mycelial growth inhibition in dual culture. All selected species produced volatile metabolites which prevented radial growth of pathogen from 40.4% to 85%. Also, the growth inhibition percentage in the method of production non-volatile compounds varied from 14.7 to 63.82%, and the highest inhibition percentage was related to T. brevicompactum (LT134) species. The results of greenhouse experiments showed that T. brevicompactum (LT134) species increased the dry weight and height shoot by 115% and 50%, respectively. While T. harzianum (LT12) species increased 155% and 55.5% dry weight and root length, respectively. The lowest disease severity index with 30% was related to T. harzianum species. All the isolates had a positive effect on bean growth without pathogenic agents. Which proved the ability of Trichoderma as plant growth promoter. The results this research proved the antagonist capacity of Trichoderma isolates against bean root rot caused by R. solani. Also, they reduced the severity of bean root rot disease. Based on the present finding, the T. harzianum (LT12) and T. brevicompactum (LT134) have interesting potential biocontrol features. However, further studies are needed in order to determine the compatibility of this isolates with other beans biofertilizers. Consequently, the incorporation of Trichoderma with biological formulates, in an integrated plan management for the control of R. solani in beans crop, could be very important.