Screening and Application of Phylloplane microorganisms for biological control of foliar plant pathogenic fungi

Epiphytic microorganisms were isolated from phyllosphere of chinese kale and mango by washing and grinding of leaf for serial dilutions preparation. Each dilution ws spread on five media including King’s medium B, Thornton’s Standardized Agar, Nutrient Glucose Agar, Yeast extract-Malt extract Agar and Leaf Decoction Agar. Most of the isolated antagonistic microorganisms were yeast and bacteria. Grinding of leaf was the best method for epiphytic microorganism isolation, because many different characteristics of microorganisms were detected more than washing leaf printing method. Seventy seven isolates of microorganisms from chinese kale phyllosphere (WS1-WS77) were tested in vitro for growth inhibition of Alternaria sp. on PDA. Fifty isolates which inhibited growth of the pathogen for 19.35-48.39 percent, by producing antibiotic(s) or metabolite(s) (clear zone occurrence) and by showing rapid growth were selected for testing on the efficacy to control cninese kale leaf blight by detached leaf technique. Result showed that 24 isolates significantly reduced size of lesions when compared with a control, at 5 days after inoculation with agar discs of Aiternaria sp. The two effective isolates WS 16 and WS 18 were identified as Bacillus spp. Fifty nine isolates of microorganisms from mango phyllosphere (CG1-CG59) were tested in vitro for growth inhibition of Colletotrichum gloeosporioides on PDA. Thirty four isolates which inhibit the pathogen for 17.19-34.38 percent were selected for testing the efficacy to control anthracnose by detached leaf technique. Inoculation on detached leaf was performed by using agar discs of C. gloeosporioides or spraying with spore suspension (10**(4) spore/ml). Result showed that 10 and 20 isolates significantly reduced size of lesions when compared with control, at 5 days after inoculation by detached leaf technique and spore suspension spraying, respectively.