Isolation and Characterization of Pomegranate (Punica granatum L.) Endophytes

Abstract

Endophytic fungi and bacteria were isolated from leaf and shoot of apparently healthy pomegranate plants. The plant samples were collected from 5 different districts of northern Karnataka which includes Bagalkote, Belagavi, Gadag, Koppal and Vijayapura. Totally 101 endophyes were isolated using standard isolation technique. Among them 69 were fungal endophyes (31 from leaf and 38 from shoot), and 38 were bacterial endophytes (18 from leaf and 14 from shoot). Cultural characters of fungal and bacterial endophyes were studied on potato dextrose agar and nutrient agar medium respectively. Among the 69 fungal isolates, growth characters of colony varied from white to grey and black on upper surface and pale yellow to light brown and black on lower surface, regular to irregular margin, fluffy to flat mycelial growth and smooth to coarse texture on PDA. Colony diameter ranged from 2.4 to 8.5 cm but maximum number of isolates showed above 8.0 cm colony diameter after ten days of incubation. The growth of isolates on nutrient agar medium showed considerable differences with respect to colony colour, appearance (form), elevation and margin. Colony colour varied from dull white to bright yellowish, circular to irregular form, flat to raised elevation and undulated to entire margin. Further these endophytes were evaluated against pomegranate wilt pathogens like Ceratocystis fimbriata and Fusarium oxysporum.