Characterization, Screening and Application of Rhizobial Isolates on Black Gram [Vigna mungo (L.) Hepper] Productivity from the Rhizosphere Soil of Dibru-Saikhowa Biosphere Reserve (DSBR) Forest of Assam, India

Abstract

An experiment was conducted with efficient Rhizobial isolates from the rhizosphere soil of Dibru-Saikhowa Biosphere Reserve (DSBR) forest of Assam, India in both laboratory and field condition with black gram. The purification, authentication, characterization and screening of efficient isolates viz. MDB1 (Microbial Diversity Bacteria), MDB9, MDB11, MDB12 and MDB15 have been done in vitro experiment in Gibson’s tube and Leonard jars. Lone inoculation of these five isolates in black gram with prominent parameters like dry weight (g, plant-1) of shoot and root, chlorophyll content (mg, g-1fresh wt.), N & P content (g/plant) and yield (kg, ha-1) were recorded in field condition. Dry weight of nodule (51 g, plant-1), shoot (7.80 g, plant-1) and root (3.55 g, plant-1) was observed high in MDB11 inoculation while low (nodule= 34, shoot= 5.60 and root= 2.30 g, plant-1) in MDB15. The N & P content showed high (3.15 & 1.86 mg/plant in shoot and 1.69 & 1.06 mg/plant in root) in MDB11 inoculation comparison to others. Subsequently, the highest productivity (460.48 kg, ha-1) of the test crop observed in due application of MDB11 while lowest (365.32 kg, ha-1) in MDB15. In this piece of research work, we used all the above-mentioned Rhizobium isolates as PGPR (Plant Growth Promoting Rhizobacteria) which were isolated from Dibru-Saikhowa Biosphere Reserve Forest of Assam. This study thus underlines the potentials of the rhizobial isolates correspondence to the growth and development of black gram and submits this piece of work in original form for greater benefit of mankind in future.