ISSN:
1432-203X
Keywords:
Alfalfa/R. meliloti symbiosis
;
Nodulation
;
Symbiotic nitrogen fixation
;
nod gene induction
;
Alfalfa varieties
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary Different nodulation capacities were found among nine different varieties of alfalfa, cultivated in the Central region of Mexico, by Rhizobium meliloti 2011. A correlation between nodulation capacity and foliar dry weight was observed, which points to a genotype dependance on these parameters. A correlation between the nodulation capacity and the R. meliloti nod-gene inducing activity of the root exudates from the different varieties, as measured by β-galactosidase induction in a test system consisting of a R. meliloti nodC-lacZ strain incubated with each root exudate, was established. When the root exudate from the best nodulating variety was added to the four poorest nodulating varieties, an increase in nodule formation was observed. We conclude that root exuded nod-gene inducing signals are a symbiotically-limiting component in natural populations of the poorest nodulating varieties of alfalfa.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00232726
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