Diversity of Endophytic Actinomycetes from Wheat and its Potential as Plant Growth Promoting and Biocontrol Agents

A total of 35 endophytic actinomycetes strains was isolated from the roots, stems and leaves tissues of healthy wheat plants and identified as Streptomyces sp. (24), Actinopolyspora sp. (3), Nocardia sp. (4), Saccharopolyspora sp. (2) Pseudonocardia (1) and Micromonospora sp. (1). Seventeen endophytic actinomycetes isolate showed abilities to solubilize phosphate and produce IAA in the range of 5 to 42mg/100ml and 18-42µg/ml respectively. Nineteen isolates produced catechol-type of siderophore ranging between 1.3-20.32µg/ml. Also, hydroxamate-type siderophore produced by 9 isolates in the range of 13.33-50.66µg/ml. Maximum catechol-type of siderophore production was observed in Streptomyces roseosporus W9 (20.32µg/ml) which was also displaying maximum antagonistic activity against ten different pathogenic fungi. The results indicated that internal tissues of healthy wheat plants exhibited endophytic actinomycetes diversity not only in terms of different types of isolates but also in terms of functional diversity.