ISSN:
1573-5036
Keywords:
common bean
;
15N
;
Phaseolus vulgaris
;
rhizobial diversity
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Abstract A field experiment under rainfed conditions was conducted in Durango, México, to assess N2-fixation of three cultivars of common bean (Phaseolus vulgaris L.) using 15N-methodology. In addition, diversity of rhizobial isolates obtained from nodules of the different plant genotypes was evaluated by intrinsic antibiotic resistance (IAR), PCR using enterobacterial repetitive intergenic consensus (ERIC) primers, PCR-RFLP analysis of the 16S rRNA gene and multilocus enzyme electrophoresis (MLEE). Selected isolates were used to determine acetylene reduction and competitive ability under greenhouse conditions. The three cultivars tested did not show high variation in N2-fixation, the %Ndfa values ranged from 19 to 26%. Variability in N2-fixation efficiency among various native rhizobial isolates was very high and our results indicate that differences in competitive abilitiy exist also. PCR-RFLP of the 16S rRNA gene and MLEE revealed that most of the isolates belong to the species Rhizobium etli. Intrinsic antibiotic resistance analysis and ERIC-PCR showed high diversity among isolates. In contrast, our results using MLEE show low genetic diversity (H = 0.105).
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1004399531966
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