Isolation and identification of Trichoderma species and investigating their seed treatment effect on rapeseed (Brassica napus L.) germination

Abstract

Trichoderma fungus species are highly populations of fungi in world that they can colonize roots as plant symbiosis. Various types of Trichoderma are free-living fungi that are, generally, saprophytic on the remains of soil. In addition to its role in biological control, this fungus increases plant yield and growth. So far, many studies have been conducted to examine the ability of this agent to reduce biological tensions and biological control of plant pathogens. Thus, this study was conducted to isolate and identify species of Trichoderma fungus from rapeseed fields in Golestan and Qazvin province from Iran, and also to study isolated species on germination percentage and growth parameters of rapeseed seedlings in a randomized complete block design with three replications in vitro. Based on the results, three species of T. harzianum, T. virens, and T. atroviride were identified, which the isolate of T. harzianum Ta19 showed a significant effect on the control group and other treatments in increasing germination percentage, root length and stem; whereas, the seeds treated with the isolate T. atroviride Ta11 showed no significant difference with the control group in spite of the increase in seed germination rate in comparison with the control and other treatments. According to the results, the use of Trichoderma fungus as a seed treatment like other researches on different products is recommended for increasing the growth of rapeseed.