Abstract
The main aim of this study was to molecular identification and determine the antagonistic impact of rhizosphere Trichoderma spp. against some phytopathogenic fungi, including (Magnaporthe grisea) pyricularia oryzae, Rhizoctonia solani and Macrophomina phasolina. Four Trichoderma isolates were isolated from rhizosphere soils of the different host plants in different locations of Egyptian governorates. The morphological characterization of isolated Trichoderma as well as using of (ITS1-5.8S-ITS2) ribosomal gene sequence acquisition and data analyses. By comparing the results of DNA sequences of ITS region, the fungi represented one isolate were positively identified as T. asperellum (1 isolate T1) and one as T. longibrachiatum (1 isolate T2) and two as Trichoderma harzianum (2 isolates T3 and T4). The results showed similarity value of (5.8S-ITS) region sequence of the two isolates, T1 (T. asperellum) and T2 (T. longibrachiatum) of (99%, 99%), respectively. The similarity value of (5.8S-ITS) region sequence with isolates of T3, T4 (T. harzianum) of (99%). On the other side, the results of molecular identification of phytopathogenic fungi represented high similarity value of (5.8S-ITS) region sequence and were identified as P.oryzae, R. solani and M. phasolina (99, 96 and 99%) respectively. Variations and genetic relationships among 4 Trichoderma isolates were investigated by using the Rapid Amplification of Polymorphic DNA (RAPD) profiles using ten random primers. All Trichoderma isolates were assessed for their antagonistic impact on phytopathogens P. oryzae, R. solani and M. phasolina. Though T. harzianum isolates were more affects than T. longibrachiatum and T. asperellum isolates, the percent inhibitory effect among T. harzianum isolates were vary much (44.8 to 91.6%). The inhibitory effect of T. asperellum isolates ranged from 42.2 to (86.0%), while T. longibrachiatum exhibiting affect ranged between (47.5%) to (83.8%).
Highlights
Biological control agents (BCAs) could be available alternative way over chemicals treatments in management of fungal crop diseases
According to the blast search results among of these isolates, the internal transcribed spacer (ITS) region of four isolates (T1,T2,T3 and T4) submitted to National Center for Biotechnology Information (NCBI) and representing the first isolate identified as T. asperellum (T1), the second isolate identified as T. longibrachiatum (T2), while the isolates of (T3 and T4) identified as T. harzianum
Isolates of plant pathogens were used in this study identified according to the ITS regions of ribosomal genes and have high similarity percentage of (5.8S-ITS) according to the blast results, these isolate were identified as (P.oryzae, R. solani and M. phasolina) and the percentage of homology were (99, 96 and 99%) respectively (Table 1)
Summary
Biological control agents (BCAs) could be available alternative way over chemicals treatments in management of fungal crop diseases. All members of genus Trichoderma are free living and known as imperfect fungi (Deuteromycetes), fast growing in culture and have the ability to produce several types of green spores. These occur worldwide and are commonly found in the soil environments and associated with roots of plant and debris [1]. The potential effect of Trichoderma species as biological control agents in plant disease control was introduced in the early 1930s by [2] who was first researcher elucidate the mycoparasitic activity of the members of Trichoderma genus against wide range of microorganisms like soil-born fungal and bacterial pathogens.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
