Diversity of Powdery Mildew Mycoparasite Ampelomyces quisqualis under Natural Ecosystem and Its Molecular Characterization

Abstract

The powdery mildew are the most common diseases which widely affect crops in many countries. The mildew infection appeared on leaves, petiole, buds, inflorescence and other tender tissues of crops causing 65% of the crop loss. Even though the fungicidal spray to control the disease, the residual and environmental effects are causing long term ecological imbalance in cropping system. Recently, an alternative and eco-friendly mycoparasite associated with powdery mildew pathogens was used against Erysiphe sp, Leveilulla sp, Sphaerotheca sp and Oidium sp. This study aimed to mitigated the use of the expensive and harmful fungicides to save human health and to reduce the financial costs of controlling the fungal infections of crops in the field by using a commercial biofungicide naturally associated with different species of powdery midew fungi. Our results exhibited that the isolation of the mycoparasite Ampelomyces quisqualis from the mildew pathogens was closely associated with most of the genera of powdery mildew pathogens. The natural mycoparasitization efficiency of A. quisqualis was observed and higher (81%) efficiency was recorded in Erysiphe cichoracearum followed by 76% in black gram powdery mildew caused by Erysiphe polygoni. A total of 20 mycoparasitic Ampelomyces isolates were enumerated from pycnidia of 6 different powdery mildew species that naturally infected their host plants. The pycnidial morphological variations of A.quisqualis and the largest size of pycnidia was found in the Erysiphe chichoracearum (73.54µm length × 42.15µm width) shows maximum efficiency in natural parasitization. The molecular characterization of A.quisqualis isolates based on using rDNA ITS region was carried out and sequenced. The phylogenetic analysis was performed using the Maximum likelihood technique was shown the distinct relatedness with five Ampelomyces isolates made in the present study were clustered. This is the first and detailed study on diversity of Ampelomyces and quantification of natural mycoparasitism of different genera of powdery mildew of A. quisqualis.