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Genetic variability of rhizobacteria from wild populations of four Lupinus species based on PCR‐RAPDs §
Author(s) -
Lucas García José Antonio,
Probanza Augustín,
Ramos Beatriz,
Gutiérrez Mañero Francisco J.
Publication year - 2001
Publication title -
journal of plant nutrition and soil science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.644
H-Index - 87
eISSN - 1522-2624
pISSN - 1436-8730
DOI - 10.1002/1522-2624(200102)164:1<1::aid-jpln1>3.0.co;2-l
Subject(s) - rhizosphere , biology , rhizobacteria , botany , lupinus , pseudomonas , genetic diversity , intraspecific competition , bacteria , genetics , population , zoology , demography , sociology
The metabolic capacities of rhizosphere bacteria can depend on intraspecific genetic variability at strain level. We sampled bacteria from the rhizosphere of three populations of four different Lupinus species at two growth stages (flowering: GS1 and fruiting: GS2). Isolates were identified to the genus level by classical biochemical tests. The most abundant genera found were Bacillus, Aureobacterium, Cellulomonas, Pseudomonas , and Arthrobacter . Genetic divergence of rhizobacteria was tested by PCR‐RAPDs. The genetic distances were low, with mean values of 37 % for Bacillus , 25 % for Aureobacterium , 46 % for Cellulomonas , 16 % for Pseudomonas , and 23 % for Arthrobacter. Aureobacterium , the most abundant genus, predominated in the rhizosphere of all populations and at both growth stages (GS1 and GS2) of L. angustifolius . The Aureobacterium strains consisted of 11 groups with 90 % similarity indexes. The cluster analysis of these groups shows that strains isolated from different lupin species and sampling times have extraordinary low diversity indexes, or are even identical. This fact, together with the low genetic distance detected in the rhizosphere, reveals a clear specificity in the plant‐bacteria interaction. This specificity could be related with several aspects of plant physiology.