A.K. Saxena FNAAS, FIAMS
Dr A.K. Saxena is the Director of ICAR-National Bureau of Agriculturally important Microorgansims. His major research interests are in the area of plant – microbe interactions and molecular diversity analysis of bacteria. He documented and characterized bacterial diversity of extreme environments and identified novel genera. He developed bacterial inoculants, including novel biofilmed formulations, Zn and K solubilizers and NPK providing combinations for integrated nutrient management. He successfully transferred the technologies to entrepreneurs, leading to increased coverage of land under microbial inoculants. He has worked on legume-Rhizobium symbiosis under salt and nitrate stress, as well as the diversity of green gram and soybean rhizobia. He is the National Coordinator of the megaproject on ‘Application of Microorganisms in Agriculture and Allied Sectors’ which includes 55 projects on different thematic areas. At present he works on developing rhizobial inoculants with the dual purpose of nitrogen fixation and antagonism against pathogens of chickpea, lentil and peas.
As part of the IUNFC project, his work will be focussed on improving Pigeonpea-Rhizobium symbiosis for enhanced productivity under drought stress in alluvial soils (Inceptisols) of Indo gangetic region. Cajanus cajan (L.) Millspaugh (Pigeonpea) is the second most important legume crop after chickpea in India. It is a deep rooted and drought tolerant crop that is grown on marginal lands with minimum inputs. The national productivity of pigeonpea is low and is constrained by the use of less productive land, water logging or dry spells during critical stages of crop growth. Other problems associated with pigeonpea is the nodulation behaviour and pattern; the nodules are fragile, senescence sets in fast; and only in the presence of moisture the nodules are formed in the deeper layers. There is a need to develop Rhizobium strains that can tolerate drought stress; saprophytically persist in soil under dry spells; has the ability to migrate from the point of placement with speed of nodulation; high nodulation competitiveness under drought and high temperature stress; forms effective nodules throughout the root system with high leghaemoglobin content and persistent bacteroid even during drought stress during vegetative phase. Therefore his research work will focus on identification of combinations of pigeon-pea cultivars and specific Bradyrhizobium strains that could improve nodulation, symbiotic nitrogen fixation, growth and yield of crop in alluvial cells. It will include isolation of rhizobia specific to pigeopea from different sites; identification of strains efficient for nitrogen fixation and growth of crop; developing combinations of efficient strains with short and medium duration genotypes of pigeopea; evaluation of the combinations under field conditions and to estimate the contribution of BNF by N difference method.