Molecular diversity, effectiveness and competitiveness of indigenous rhizobial population infecting mungbean Vigna radiata (L. Wilczek) under semi-arid conditions

Abstract

Nodules from mungbean crop raised for the fi rst time at Ram Dhan Singh (RDS) farm of Chaudhary Charan Singh (CCS) Haryana Agricultural University, Hisar were collected from 17 different locations. Twentyfi ve mungbean rhizobia were isolated and authenticated by plant infection test. DNA of all these rhizobia was extracted purifi ed and amplifi ed using enterobacterial repetitive intergenic consensus (ERIC) primers. All the mungbean rhizobial isolates were clustered into 4 groups at 65% of similarity and were further divided into 17 subclusters at 80% of similarity. All the 4 types of rhizobia were not present at any of the location and group 2 or 4 rhizobia were invariably present. Effi cacy of these rhizobia in terms of nodulation, nitrogen uptake and chlorophyll a fl uorescence was determined under pot culture conditions. Strain MB 307 showed maximum nitrogen uptake of 31.9 mg N plant -1 followed by strain MB 1205, MB 1206(2), MB 308, MB 1524 and strain MB 1521 was found to be the least effi cient in terms of N 2 fi xation. Nodule occupancy by different rhizobia ranged from 5.5 to 40.3%. Most of the strains belonging to the 2nd group which clustered maximum number of strains were comparatively better competitors and formed 19.5-40.3% of the nodules and were also effective. Isolate MB 307, the most effi cient strain, was found to have nodule occupancy of 31.5%. Such type of predominant, effi cient and better competitor strains should be selected for enhancing nodule competitiveness.

Molecular diversity of native rhizobia trapped by five field pea genotypes in Indian soils

“…Similarly, high variability of effectiveness of rhizobia was reported in chickpea, mungbean, Vicia, Lathyrus, pea, soybean, lima bean, cowpea, bush bean, peanut, Leucaena leucocephala, tinga pea, alfalfa and clover [6,17,19,[31][32][33].…”

Widespread fitness alignment in the legume–rhizobium symbiosis

“…(2003); HUN98, Hungria et al. (1998); KUN08, Kundu & Dudeja (2008); LAG07, Laguerre et al. (2007); NUR88‐89, Nurhayati et al.…”