Selection and control efficiency of Trichoderma isolates against Fusarium oxysporum f. sp. ciceris in Iran

Abstract

The antagonistic potential of forty isolates of Trichoderma spp. obtained from major chickpea growing areas in western part of Iran, were evaluated against Fusarium oxysporum f. sp. ciceris, the most important soil-born pathogen of chickpea. Among those, six species of Trichoderma harzianum, T. longibrachiatum, T. pleurotum, T. crassum, T. guizhouense,and Trichoderma sp. were identified based on morphological, molecular and phylogenetic analysis of concatenated DNA sequences of tef1 and rpb2 genes. All isolates were tested in vitro using dual culture method for their inhibition of the mycelial growth of the pathogen. Eight most antagonistic isolates, which suppressed colony growth of pathogen by 61.1–65.5%, were tested in vitro for production of volatile metabolites. All eight selected isolates produced volatile metabolites which prevented radial growth of pathogen from 17.5% to 31.0%. Antagonistic isolates provided significant protection against pathogen when mixed with soil or treated on seeds. Wilt control efficiency was greater for T. longibrachiatum KT8 (64.4%), T. harzianum KT9 (66.1%), and KT10 (69.5%) after 60 days of sowing highly susceptible chickpea cultivar JG-62 in inoculated soils. Greater wilt control efficiencies were detected for seed treatments with KT8 (69.1%), KT9 (72.7%), and KT10 (74.5%) isolates. Higher plant height, dry weight of root and shoot were recorded with these three superior isolates in seed treatments, inoculated and non-inoculated soils. Such superior isolates could be considered as promising antagonistic agents in biocontrol of chickpea Fusarium wilt for future studies. To the best of our knowledge, T. pleurotum and T. guizhouense are reported for the first time from Iran.