Isolation, identification, and molecular diversity of indigenous isolates of Beauveria bassiana from Taif region, Saudi Arabia

Abstract

The entomopathogenic fungus, Beauveria bassiana causes a disease known as the white muscadine disease in insects. Most of the entomopathogenic fungi are soil borne nature an attempt was made to collect the soil samples from various ecosystems. Therefore, the present study aimed to isolate native strains of B. bassiana and study their genetic diversity at Taif region, Saudi Arabia, using ITS of nuclear DNA and COI gene analysis by comparing of different isolates from occasional localities through the world. Ninety-four soil samples were collected from different regions at Taif. Only 11 samples had B. bassiana fungus with a ratio of 11.7%. Sequences of ITS (593 bp), and partial COI (437 bp) of these isolates were carried out and revealed that four differed in their genetics. These sequences were deposited in the DDBJ GenBank database with eight accession numbers. Consequently, the three analytical methods (MP, NJ, and ML) executed a single tree with identical topology. The tree identified the studied isolates into two main clusters; the first contained Uzbekistan and USA isolates. The Chinese isolate clustered with this group in the MP tree and was diverged as a single cluster in the NJ tree. The second clade included the newly studied four isolates from Taif and the Italian isolate. The pairwise genetic distances among the four studied isolates (D ranged between 0.002 and 0.008) showed that they were genetically closely related. Further studies are needed to indicate more differentiation among these isolates and to evaluate their efficacy against the important insect pests in Saudi Arabia.