Characterization of some non-fixing mutants of common bean (Phaseolus vulgaris L.)

1993 ◽  
Vol 73 (4) ◽  
pp. 977-983 ◽  
Author(s):  
B. R. Buttery ◽  
S. J. Park

With 18 strains of Rhizobium leguminosarum bv. phaseoli the bean mutants R99 and NOD125 remained essentially non-nodulating, while the mutant R69 produced a variable number of small white ineffective nodules, and the wild-type parent-line OAC Rico formed a variable number of pink effective nodules. Both R69 and R99 grew less vigorously than OAC Rico, but possessed similar levels of nitrate reductase in both roots and leaves, and responded in a normal way to increased supply of combined nitrogen. Reciprocal grafts between the non-nodulating R99 and NOD125, the ineffective R69, the wild-type parent line OAC Rico, and the supernodulating R32BS, demonstrated that the non-nodulating and ineffective characters were controlled by the root, and confirmed that the supernodulation character was controlled by the shoot. Key words: Common bean, nitrate reductase, non-fixing mutants, Phaseolus vulgaris, Rhizobium strains, supernodulation

1996 ◽  
Vol 76 (1) ◽  
pp. 73-83 ◽  
Author(s):  
Steven J. Shirtliffe ◽  
J. Kevin Vessey ◽  
B. R. Buttery ◽  
S. J. Park

Nodulation mutants are present in many species of legumes and have potential as ideal reference crops in field measurements of N2 fixation. The objective of this experiment was to characterize the growth, development, mineral-N accumulation, and N2 fixation of two nodulation mutants of common bean (Phaseolus vulgaris L.), R69 (nod+/fix−) and R99 (nod−) in comparison with the wild type parent OAC Rico. The mutants were incapable of N2 fixation. With dual dependence on N2 fixation and [Formula: see text] as N sources, OAC Rico accumulated more N than R69 and R99. However, when supplied with mineral [Formula: see text] sufficient to prevent N2 fixation in OAC Rico, its growth and N accumulation did not differ from those of the mutants. There were differences in internode length that resulted in different heights among the three lines. The addition of silver to the nutrient solution failed to restore nodulation to R99. As a result, it was determined that the nod− phenotype is not a result of an ethylene-related mutation. The nodulation mutants R69 and R99 appear to be good choices as reference crops for common bean in N2 fixation studies. Key words: Common bean, N accumulation, N2 fixation, nodulation mutants, Phaseolus vulgaris, Rhizobium leguminosarum bv. phaseoli


1990 ◽  
Vol 70 (4) ◽  
pp. 987-996 ◽  
Author(s):  
B. R. BUTTERY ◽  
S. J. PARK ◽  
S. BERNARD ◽  
W. STREIT ◽  
D. WERNER

Numbers of nodules formed on both the supernodulating common bean (Phaseolus vulgaris L.) line R32-BS (BS) and its parent cultivar (OAC Rico) increased with Rhizobium inoculum concentration up to about 105 cells mL−1. As numbers of nodules increased, their average size decreased. Red nodules as a fraction of total nodules decreased with increasing numbers of nodules: a large proportion of nodules at the higher concentrations appeared to be non-functional. Acetylene reduction (AR) rates per plant did not differ between supernodulator and parent line. AR per gram total nodule fresh weight was greater in the parent line than in the supernodulator, but AR per gram red nodule weight was the same in the two lines. Combined nitrogen had its main effect in increasing plant weight, but had little effect on nodule characteristics. However, nodule weights/numbers per unit plant weight were decreased by combined nitrogen. OAC Rico and BS responded similarly to N. Rhizobium strain TAL182 produced fewer but more efficient nodules than Kim5s.Key words: Rhizobium leguminosarum bv. phaseoli, Phaseolus vulgaris, supernodulation, nodule number, nodule senescence, inoculum concentration


2021 ◽  
Author(s):  
Sofora Jan ◽  
Irshad Ahmad Rather ◽  
Parvaze Ahmad Sofi ◽  
Mohd Altaf Wani ◽  
Farooq Ahmad Sheikh ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Evdoxia Efstathiadou ◽  
Georgia Ntatsi ◽  
Dimitrios Savvas ◽  
Anastasia P. Tampakaki

AbstractPhaseolus vulgaris (L.), commonly known as bean or common bean, is considered a promiscuous legume host since it forms nodules with diverse rhizobial species and symbiovars. Most of the common bean nodulating rhizobia are mainly affiliated to the genus Rhizobium, though strains belonging to Ensifer, Pararhizobium, Mesorhizobium, Bradyrhizobium, and Burkholderia have also been reported. This is the first report on the characterization of bean-nodulating rhizobia at the species and symbiovar level in Greece. The goals of this research were to isolate and characterize rhizobia nodulating local common bean genotypes grown in five different edaphoclimatic regions of Greece with no rhizobial inoculation history. The genetic diversity of the rhizobial isolates was assessed by BOX-PCR and the phylogenetic affiliation was assessed by multilocus sequence analysis (MLSA) of housekeeping and symbiosis-related genes. A total of fifty fast-growing rhizobial strains were isolated and representative isolates with distinct BOX-PCR fingerpriniting patterns were subjected to phylogenetic analysis. The strains were closely related to R. anhuiense, R. azibense, R. hidalgonense, R. sophoriradicis, and to a putative new genospecies which is provisionally named as Rhizobium sp. I. Most strains belonged to symbiovar phaseoli carrying the α-, γ-a and γ-b alleles of nodC gene, while some of them belonged to symbiovar gallicum. To the best of our knowledge, it is the first time that strains assigned to R. sophoriradicis and harbored the γ-b allele were found in European soils. All strains were able to re-nodulate their original host, indicating that they are true microsymbionts of common bean.


2013 ◽  
Vol 62 ◽  
pp. 79-87 ◽  
Author(s):  
Maruška Budič ◽  
Jerica Sabotič ◽  
Vladimir Meglič ◽  
Janko Kos ◽  
Marjetka Kidrič

1994 ◽  
Vol 40 (3) ◽  
pp. 208-215 ◽  
Author(s):  
M. L. C. George ◽  
J. P. W. Young ◽  
D. Borthakur

Rhizobium sp. strain TALI 145 nodulates Leucaena ieucocephaia and Phaseolus vulgaris, in addition to a wide range of tropical tree legumes. Six overlapping clones that complemented nodulation defects in leucaena and bean rhizobia were isolated and a 40-kb map of the symbiosis region was constructed. The common nod and nifA genes were situated approximately 17 kb apart, with the nodlJ genes in between. These clones enabled a derivative of TAL1145 carrying a partially deleted pSym to form ineffective nodules on both leucaena and bean, and a similar derivative of Rhizobium etli TAL182 to form ineffective nodules on bean. When two representative clones, pUHR9 and pUHR114, were each transferred to wild-type rhizobial strains, they allowed ineffective nodulation by Rhizobium meliloti on both leucaena and bean and by Rhizobium leguminosarum bv. viciae on bean. Transconjugants of R. leguminosarum bv. trifolii formed effective nodules on leucaena and ineffective nodules on bean. Tn5 mutagenesis of the symbiosis region resulted in a variety of nodulation and fixation phenotypes on leucaena and bean. On the basis of 16S rRNA sequences, TAL1145 was found to be distinct from both R. tropici and NGR234, the two groups of leucaena symbionts that were previously described.Key words: Rhizobium, Leucaena leucocephala, nodulation, nitrogen fixation.


Author(s):  
Isabel Webb ◽  
Jiabao Xu ◽  
Carmen Sanchez-Cañizares ◽  
Ramakrishnan Karunakaran ◽  
Vinoy Ramachandran ◽  
...  

Symbiosis between Rhizobium leguminosarum and Pisum sativum requires tight control of redox balance in order to maintain respiration under the microaerobic conditions required for nitrogenase, whilst still producing the eight electrons and sixteen molecules of ATP needed for nitrogen fixation. FixABCX, electron transfer flavoproteins essential for nitrogen fixation, are encoded on the Sym plasmid (pRL10), immediately upstream of nifA, which encodes the general transcriptional regulator of nitrogen fixation. There is a symbiotically-regulated NifA-dependent promoter upstream of fixA (PnifA1), as well as an additional basal constitutive promoter driving background expression of nifA (PnifA2). These were confirmed by 5’-end mapping of transcription start sites using differential (d) RNA-seq. Complementation of polar fixAB and fixX mutants (Fix- strains) confirmed expression of nifA from PnifA1 in symbiosis. Electron microscopy combined with single-cell Raman microspectroscopy characterization of fixAB mutants revealed previously unknown heterogeneity in bacteroid morphology within a single nodule. Two morphotypes of mutant fixAB bacteroids were observed. One was larger than wild-type bacteroids and contained high levels of polyhydroxy-3-butyrate, a complex energy/reductant storage product. A second bacteroid phenotype was morphologically and compositionally different and resembled wild-type infection thread cells. From these two characteristic fixAB mutant bacteroid morphotypes, inferences can be drawn on the metabolism of wild-type nitrogen-fixing bacteroids.


Plant Disease ◽  
2021 ◽  
Author(s):  
Kelvin Kamfwa ◽  
Paul Gepts ◽  
Swivia Hamabwe ◽  
Zombe Kapata Nalupya ◽  
Chikoti Mukuma ◽  
...  

Colletotrichum lindemuthianum, the causal pathogen of common bean (Phaseolus vulgaris) anthracnose, is highly variable. Therefore, understanding its race structure and identification of new sources of resistance is necessary for the development of varieties with durable resistance. The objectives of this study were (i) to characterize isolates of C. lindemuthianum collected from three major bean-growing regions in Zambia, and (ii) evaluate the CIAT Phaseolus core collection for resistance to C. lindemuthianum races 37, 73, and 566, and a blend of 20 races. Isolates collected from three major bean-growing districts in Zambia, namely Mporokoso, Mpika, and Mbala, were characterized as race 37, 73, and 566, respectively. A subset of the CIAT core collection comprised of 885 accessions of common bean, 13 accessions of scarlet runner bean (P. coccineus), and 11 accessions of year bean (P. dumosus) were evaluated for resistance to races 37, 73 and 566, and a blend of 20 races in a greenhouse at University of Zambia, Lusaka, Zambia. A total of 72%, 66%, 48% and 9% of P. vulgaris accessions evaluated were highly resistant to races 37, 73, 566 and a blend of 20 races, respectively. Also, accessions of P. coccineus and P. dumosus, highly resistant to races 37, 73 and 566, were identified. Only eight of the 331 P. vulgaris accessions were highly resistant to all three individual races (37, 73, and 566) and to a blend of 20 races. These eight accessions constitute a valuable breeding resource for developing varieties with durable resistance to C. lindemuthianum.


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