Registration of Barc‐2 (Rj4) and Barc‐3 (rj4) Soybean Germplasm

Devine, T. E.; O'Neill, J. J.

doi:10.2135/cropsci1986.0011183x002600060055x

Cited by 18 publications

(4 citation statements)

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“…nd= not determined. the Rj4 vs. the rj4 allele (Devine and O'Neill, 1986). These lines are calculated to be 99.95% identical in their nuclear D N A and completely identical in their cytoplasmic DNA.…”

Section: Genetically Defined Traits"mentioning

confidence: 95%

Host genetic control of symbiosis in soybean (Glycine max L.)

Devine¹,

Kuykendall²

1996

Plant Soil

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Genes controlling nitrogen-fixing symbioses of legumes with specialized bacteria known as rhizobia are presumably the products of many millions of years of evolution. Different adaptative solutions evolved in response to the challenge of survival in highly divergent complexes of symbionts. Whereas efficiency of nitrogen fixation appears to be controlled by quantitative inheritance, genes controlling nodulation are qualitatively inherited. Genes controlling nodulation include those for non-nodulation, those that restrict certain microsymbionts, and those conditioning hypernodulation, or supernodulation. Some genes are naturally occurring polymorphisms, while others were induced or were the result of spontaneous mutations. The geographic patterns of particular alleles indicate the role of coevolution in determining symbiont specificities and compatibilities. For example, the R j4 allele occurs with higher frequency (over 50%) among the soybean (G. max) from Southeast Asia. DNA homology studies of strains of Bradyrhizobium that nodulate soybean indicated two groups so distinct as to warrant classification as two species. Strains producing rhizobitoxine-induced chlorosis occur only in Group II, now classified as B. elkanii. Unlike B. japonicum, B. elkanii strains are characterized by (1) the ability to nodulate the rjl genotype, (2) the formation of nodule-like structures on peanut, (3) a relatively high degree of ex planta nitrogenase activity, (4) distinct extracellular polysaccharide composition, (5) distinct fatty acid composition, (6) distinct antibiotic resistance profiles, and (7) low DNA homology with B. japonicum. Analysis with soybean lines near isogenic for the R j4 versus rj4 alleles indicated that the Rj4 allele excludes a high proportion of B. elkanii strains and certain strains of B. japonicum such as strain USDA62 and three serogroup 123 strains. These groups, relatively inefficient in nitrogen fixation with soybean, tend to predominate in soybean nodules from many US soils. The R j4 allele, the most common allelic form in the wild species, has a positive value for the host plants in protecting them from nodulation by rhizobia poorly adapted for symbiosis.

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Section: Genetically Defined Traits"mentioning

confidence: 95%

Host genetic control of symbiosis in soybean (Glycine max L.)

Devine¹,

Kuykendall²

1996

Plant Soil

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“…Therefore, detecting Rj 3 is based on an inoculation method using the specific B. elkanii strain USDA33. However, the nodulation phenotype of B. elkanii strain USDA33 is unstable [18]. Bradyrhizobium Type B strains, which have restricted nodule formation in Rj 2 Rj 3 -gene harboring cultivars [6] [7], can replace USDA33 and have the highest possibility of being effective for identifying the Rj 3 gene.…”

Section: Introductionmentioning

confidence: 99%

Incompatible Nodulation of Bradyrhizobium elkanii Strains BLY3-8 and BLY6-1 with Rj3 Gene-Harboring Soybean Cultivars

Htwe¹,

Yamakawa²

2017

AJPS

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Bradyrhizobia are known symbiotic partners of soybean. However, some soybean cultivars restrict nodulation by some Bradyrhizobium bacterial strains. These restrictions are related to compatibility between the Rj genes of soybean cultivars and nodulation types of inoculated bacteria. The objective of this study was to determine nodulation incompatibility of Type B strains with Rj 3 soybean cultivars. Newly isolated B. elkanii strains BLY3-8 and BLY6-1 from Myanmar and specific strain Bradyrhizobium elkanii USDA33, which are incompatible with Rj 3 soybean cultivars, and B. japonicum USDA110 were used as inoculants to check compatibility or incompatibility with Rj 3 soybean cultivars. Nitrogen fixation activity was measured by the acetylene reduction method. Ethylene concentration (reduction of acetylene) was determined by flame ionization gas chromatography. According to the inoculation test results, USDA110 was compatible with all soybean cultivars because it formed effective nodules ( Figure S1 in Appendix) and possessed nitrogenase activity.Similarly, B. elkanii strains BLY3-8, BLY6-1, and USDA33 were highly compatible with non-Rj and Rj 4 -gene harboring soybean cultivars because they had the ability to form functional nodules and possessed nitrogenase activity.Inversely, BLY3-8, BLY6-1, and USDA33 were incompatible with Rj 3 soybean cultivars because they produced ineffective nodules. Consequently, the ratio of ineffective nodule number to total nodule number was >0.5. Therefore, nodule formation by the newly isolated B. elkanii strains BLY3-8 and BLY6-1 was restricted by the Rj 3 soybean cultivars potentially making them useful as specific strains to detect the Rj 3 gene in soybean cultivars.

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“…These genetic stocks are near isogenic lines calculated to be 99.95% identical to each other in their nuclear DNA and completely identical in their cytoplasmic DNA, but differing precisely in the allele present at the Rj4 locus. BARC-2 (Rj4) is homozygous for the Rj4 allele and BARC-3 (rj4) is homozygous for the rj4 allele (Devine and O'Neill, 1986). Since these isolines differ essentially only in the allele present at the Rj4 locus, any difference between the isolines in nodulation response with individual bradyrhizobial strains can be attributed to the strain's interaction specifically with the Rj4 allele.…”

Section: Introductionmentioning

confidence: 99%

Near isogenic lines of soybeans as tools to identify nodulation specificmutants of Bradyrhizobium elkanii

1993

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The dominant allele Rj4 in soybean interdicts or restricts the nodulation of plants by certain strains of bacteria, most of which are classified as Bradyrhizobium elkanii, while the recessive allele permits normal nodulation with the same strains. The near isogenic lines BARC-2 (Rj4) and BARC-3 (rj4) are calculated to be 99.95% identical in their nuclear DNA, but differ specifically in the allele present at the Rj4 locus. These lines were used to identify spontaneous mutants of the Rj4-restricted Bradyrhizobium elkanii strain USDA 61 Nal r that had the ability to effectively nodulate plants of the Rj4 genotype. Of the eight rare nodules found on roots of soybean plants of the Rj4 genotype inoculated with the genetically marked strain USDA 61 Nal r, four were identified as containing mutants with the ability to overcome the effects of the Rj4 allele.

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Registration of Barc‐2 (Rj₄) and Barc‐3 (rj₄) Soybean Germplasm

Cited by 18 publications

References 0 publications

Host genetic control of symbiosis in soybean (Glycine max L.)

Host genetic control of symbiosis in soybean (Glycine max L.)

Incompatible Nodulation of <i>Bradyrhizobium elkanii</i> Strains BLY3-8 and BLY6-1 with <i>Rj</i>3 Gene-Harboring Soybean Cultivars

Near isogenic lines of soybeans as tools to identify nodulation specificmutants of Bradyrhizobium elkanii

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Registration of Barc‐2 (Rj4) and Barc‐3 (rj4) Soybean Germplasm

Cited by 18 publications

References 0 publications

Host genetic control of symbiosis in soybean (Glycine max L.)

Host genetic control of symbiosis in soybean (Glycine max L.)

Incompatible Nodulation of &lt;i&gt;Bradyrhizobium elkanii&lt;/i&gt; Strains BLY3-8 and BLY6-1 with &lt;i&gt;Rj&lt;/i&gt;3 Gene-Harboring Soybean Cultivars

Near isogenic lines of soybeans as tools to identify nodulation specificmutants of Bradyrhizobium elkanii

Contact Info

Product

Resources

About

Registration of Barc‐2 (Rj₄) and Barc‐3 (rj₄) Soybean Germplasm

Incompatible Nodulation of <i>Bradyrhizobium elkanii</i> Strains BLY3-8 and BLY6-1 with <i>Rj</i>3 Gene-Harboring Soybean Cultivars