oa Biodiversity in Trichoderma species isolated from Qatar

The genus Trichoderma contains a few species of soil fungi that received extensive academic and applied research. These species have been used successfully for industrial and commercial applications including biopesticides. Trichoderma species isolated from Qatar had showed thermotolerance and preference of high pH (El Badawy et al, 2016). To reveal the extent of Trichoderma species in Qatar, initial survey was carried out by isolating that fungi from samples collected from two experimental and two commercial farms. Then their antagonism against Rhizoctonia sp were evaluated. Further in order to determine the biodiversity in one location, a detailed survey was conducted by isolating Trichoderma species from 16 soil samples obtained from a single plot of 1000 m² located in one of the experimental farms. These isolates were evaluated for their potential to grow on pH 8 under 4 temperature regimes. The initial survey revealed the presence of Trichoderma (5 isolates) in all locations. The isolates differed in their morphology and antagonism against 5 isolates of Rhizoctonia sp isolated from one of the research farm. The two Trichoderma isolates from the same farms were more effective than the other three. This superiority in antagonism may reflect the coevolution of the two genera in the soil of this farm. In the detailed survey, it was remarkable to isolate three Trichoderma species (6 isolates) from the single plot. Four of the isolates were belong to one species (T. longibrachiatum). Morphological and molecular variations were observed within this species. One of the four isolates showed different colony color and conidial color than the rest. The same isolate showed a few differences at the molecular level. The sequence of the ITS rDNA (508 bp) showed substitution of 20 nucleotides (15 single, one of 2 and one of 3 nucleotides) All the three species isolates gave reasonable growth measured as dry weight even at 35 °C. There were significant differences between species in their optimum temperature which range between 25 and 30 °C. This study showed the abundant presence of the Trichoderma species in Qatari soils that could sustain and survive conditions of arid regions or the fluctuating temperature rising due to global warming. The presence of diversity between and within species will allow screening and selecting Qatari isolates with desirable characters as bio-pesticide for arid climate.

Acknowledgment: This paper is funded partially by NPRP –EP grant# [NPRP-EPX– 014-4-001] from the Qatar National Research Fund (a member of Qatar foundation). The statements made herein are solely the responsibility of the authors.