11 research outputs found
Detection of loci in the leu region of Rhizobium meliloti chromosome
A multi-marked strain of Rhizobium meliloti was developed by the co-mutation method and employed to contribute to the genetic map of R. meliloti chromosome. Seven loci were placed at 5 sites in theleu region in the orderman-aba, fix, leu-cro-azt, ost-thi
Tn5 induced mutants of iron assimilation pathway in <i>Cicer Rhizobium </i>strain, COBE13
691-695Siderophore
mutants provide an understanding of the iron assimilation pathway under iron
limiting conditions. Random Tn5 insertion mutants with varying phenotypes were
isolated in Cicer-Rhizobium strain COBE 13. Analysis on siderophore
crossfeeding plate identified these mutants as defective in siderophore
synthesis, uptake and utilization deficient in siderophore-Fe (III) complex and
in regulation
Interaction of a mutator with a mutationally stable genetic system in Escherichia coli
This article does not have an abstract
Characterization of intrinsic variability of <i style="">Mesorhizobium ciceri</i> isolates of cultivated fields
671-674A large number of putative rhizobial
isolates were obtained from the root nodules of various chickpea cultivars
growing in agricultural research fields. Of these, thirty were selected and
characterized for traits, such as, generation time, intrinsic azide resistance
and several symbiotic characters
Phenotypic and molecular characterization of indigenous rhizobia nodulating chickpea in India
340-350In a combined approach of phenotypic and genotypic characterization, 28
indigenous rhizobial isolates obtained
from different chickpea growing regions in peninsular and northern India were
analyzed for diversity. The field isolates were compared to two reference
strains TAL620 and UPM-Ca142 representing M.
ciceri and M. mediterraneum respectively.
Phenotypic markers such as resistance
to antibiotics, tolerance to salinity, temperature, pH, phosphate solubilization ability, growth rate and also
symbiotic efficiency showed considerable diversity among rhizobial isolates.
Their phenotypic patterns showed adaptations of rhizobial isolates to abiotic
stresses such as heat and salinity. Two salt tolerant strains (1.5% NaCl by T1
and T4) with relatively high symbiotic efficiency and two P-solubilising
strains
(66.7 and 71 mg/ml by T2 and T5) were identified as potential bioinoculants. Molecular profiling by 16S ribosomal DNA
Restriction Fragment Length Polymorphism (RFLP) revealed three clusters at 67%
similarity level. Further, the isolates were differentiated at intraspecific
level by 16S rRNA gene phylogeny. Results assigned all the chickpea rhizobial
field isolates to belong to three different species of Mesorhizobium genus. 46% of the isolates grouped with Mesorhizobium loti and the rest were
identified as M. ciceri and M. mediterraneum, the two species which
have been formerly described as specific chickpea symbionts. This is the first
report on characterization of chickpea nodulating rhizobia covering soils of
both northern and peninsular India.
The collection of isolates, diverse in terms of species and symbiotic
effectiveness holds a vast pool of genetic material which can be effectively used
to yield superior inoculant strains