Abstract

Analysis of diversity of phosphate solubilizers in agricultural soil is essential to understand their ecological role and their utilization in sustainable agriculture. One of the factors contributing to the success of weeds, even in nutrient limiting conditions, is the microbial community they select in their vicinity. Phosphate solubilizers from the rhizosphere of a widely growing weed, Parthenium hysterophorus, were enumerated on Pikovskaya’s medium, with an aim to screen for their plant growth promoting abilities for crops. The isolates were further assayed for multi-trait plant growth promoting properties. Two potential isolates, P1 and P2, were employed in seed germination and pot experiments with crop species. While bacterization led to an increase of 70 and 200% in shoot length in both seedling germination and pot experiments with Cajanus cajan (red gram), Vigna radiata (green gram) displayed an increase in shoot length by about 20% in pot assay using isolates P1 and P2, respectively. The present study reveals the presence of phosphate solubilizers in the rhizosphere of P. hysterophorus with plant growth promoting effect on other crop species. Due to their potential in exhibiting plant growth promoting properties, these phosphate solubilizing isolates provide a new dimension to the significance of weeds in agricultural ecosystems. The study opens up possibilities of utilization of this property of weeds in plant growth promotion, disease suppression and subsequent enhancement of yield in agriculture.

Key words: Parthenium hysterophorus, rhizosphere, phosphate solubilizers, plant growth promotion, Bacillus subtilis