Penicillium purpurogenum, Unique P Mobilizers in Arid Agro-Ecosystems

Abstract

A phosphatase and phytase producing fungus, Penicillium purpurogenum, was isolated and efficiency was tested in field on the enhancement of rhizosphere enzyme activities and mobilization of native unavailable phosphorus with pearl millet as a test crop in a loamy sand soil under arid environment. Seed inoculation with the fungi has significantly improved phosphatases (acid and alkaline), phytase, and dehydrogenase activities compared to uninoculated fields. The depletion of organic P was much higher than mineral and phytin P. The relative root growth (Kr) rate was greater between 28 and 35 days. The fungal contribution was significantly more than the plant contribution to the mineralization of mineral-P. However, both pearl millet and P. purpurogenum were equally competent for hydrolysis of phytin P. A significant improvement in plant biomass (30%), root length (21%), P uptake (6%), seed (19%) and straw yield (30%), and P concentration of shoot (15%), root (6%), and seed (33%) resulted from inoculation of P. purpurogenum. It was observed that P. purpurogenum can thrive well under arid-ecosystems. The fungus releases phosphatases and phytase, resulting in more solubilization/hydrolysis of soil unavailable P into plant available form, thereby enhancing the P uptake and pearl millet production in an arid environment.

Keywords:

• dehydrogenase
• pearl millet
• Penicillium purpurogenum
• phosphatases
• phytase
• P mobilization
• P uptake

The authors gratefully acknowledge DDG (Education) and Director (CAZRI) for their keen interest in the present study and ICAR for financial support of the National Fellow Project under which the present investigation was carried out.

Notes

*Mean value; ± indicate the standard errors of mean.