Seasonal and spatial variation of microbial population in the rhizosphere soils  of five traditionally important medicinal plant species in NE India

Chumi Khanikar; Sorokhaibam Sureshkumar Singh

Volume : IV, Issue : VI, June - 2015

Seasonal and spatial variation of microbial population in the rhizosphere soils of five traditionally important medicinal plant species in NE India

Chumi Khanikar, Sorokhaibam Sureshkumar Singh

Abstract :

The rhizospheric soils of five traditionally important medicinal plants were studied for a period of two years spreading over two seasons, summer warm and rainy season and winter cold and dry season. Fungal population, bacterial and actinomycetes population were recorded maximum during summer seasons while minimum were recorded during winter season. Bacterial population was highest (37 to 63x 106 CFU/g dry soils) followed by fungi (17to 33x 103 CFU/g dry soils) while lowest population was recorded for actinomycetes (5 to 17x105 CFU/g dry soils). Analysis of variance revealed significantly higher influence of time in terms of seasonal variation on the distribution of population of the three groups of microorgansms as compared to the plant species. The rhizosphere soils of Clerodendrum coleookianum and Asparagus racemosus displayed highest fungal population during summer seasons. Actinomycetes population was recorded lowest in the rhizosphere soil of Coptis teeta. The primary reason for variation in the distribution of bacterial population could be due to soil moisture content as revealed by significant positive correlations. Other microclimatic parameters such as soil temperature, nutrient availability and types of exudates released by plant roots could also play key roles in the distribution of microbial populations in the rhizosphere soils of medicinal plants.