The Rj4 allele in soybean represses nodulation by chlorosis-inducing bradyrhizobia classified as DNA homology group II by antibiotic resistance profiles

1990 ◽  
Vol 80 (1) ◽  
pp. 33-37 ◽  
Author(s):  
T. E. Devine ◽  
L. D. Kuykendall ◽  
J. J. O'Neill
Keyword(s):  
Antibiotic Resistance ◽  
Homology Group ◽  
Dna Homology ◽  
Group Ii

Genetic diversity in Bradyrhizobium japonicum Jordan 1982 and a proposal for Bradyrhizobium elkanii sp.nov.

1992 ◽  
Vol 38 (6) ◽  
pp. 501-505 ◽  
Author(s):  
L. D. Kuykendall ◽  
B. Saxena ◽  
T. E. Devine ◽  
S. E. Udell
Keyword(s):  
Type Strain ◽  
Homology Group ◽  
Dna Homology ◽  
Homology Groups ◽  
Hybridization Probes ◽  
Bradyrhizobium Elkanii ◽  
Group Ii ◽  
A New Species ◽  
Strain Usda ◽  
Soybean Nodulation

Fourteen randomly selected clones from cosmid libraries of Bradyrhizobium were used as hybridization probes in Southern blot analysis. Seven of the probes used were from strain USDA 83, a group II strain, and the other seven were from strain I-110, a group Ia strain. The 30 strains examined included 9 strains of Rj4-incompatible soybean bradyrhizobia. Considerable polynucleotide sequence dissimilarity between DNA homology groups was evidenced by striking differences in the number of hybridizing bands, except where the probe carried repetitive DNA. Predictable, simple restriction fragment length polymorphism differences were observed only within DNA homology groups. The previous description that 8 of 9 Rj4-incompatible strains belonged to DNA homology group II was verified. The new data, together with many previously documented differences, make it clear that the DNA homology group II organisms should be classified as a new species, for which the name Bradyrhizobium elkanii is proposed, and strain USDA 76 is designated the type strain. The ATCC number for the type strain is 49852. Key words: DNA:DNA hybridization, soybean, nodulation, bacteria, symbiosis, nitrogen fixation, host compatibility.

DNA Homology Group and the Identity of Bradyrhizobial Strains Producing Rhizobitoxine‐Induced Foliar Chlorosis on Soybean

Crop Science ◽  
1988 ◽  
Vol 28 (6) ◽  
pp. 938-941 ◽  
Author(s):  
T. E. Devine ◽  
J. J. O'Neill ◽  
L. D. Kuykendall
Keyword(s):  
Homology Group ◽  
Dna Homology

Molecular transformation of Fusarium solani with an antibiotic resistance marker having no fungal DNA homology

1989 ◽  
Vol 15 (6) ◽  
pp. 421-428 ◽  
Author(s):  
Elzbieta T. Marek ◽  
Christopher L. Schardl ◽  
David A. Smith
Keyword(s):  
Antibiotic Resistance ◽  
Fusarium Solani ◽  
Dna Homology ◽  
Resistance Marker ◽  
Antibiotic Resistance Marker ◽  
Fungal Dna

scholarly journals Pathogenic and Genetic Relatedness Among Xanthomonas axonopodis pv. allii and Other Pathovars of X. axonopodis

2005 ◽  
Vol 95 (8) ◽  
pp. 918-925 ◽  
Author(s):  
David H. Gent ◽  
Abdulwahid Al-Saadi ◽  
Dean W. Gabriel ◽  
Frank J. Louws ◽  
Carol A. Ishimaru ◽  
...  
Keyword(s):  
Homology Group ◽  
Genetic Relatedness ◽  
Dna Homology ◽  
Genomic Fingerprinting ◽  
Chain Reaction ◽  
Disease Symptoms ◽  
Xanthomonas Axonopodis ◽  
Xanthomonas Species ◽  
Polymerase Chain ◽  
Key Lime

Xanthomonas axonopodis pv. allii is phenotypically and genetically diverse and its relationship to other X. axonopodis pathovars within DNA homology group 9.2 is unknown. In growth chamber experiments, disease symptoms were produced on onion only by inoculation with X. axonopodis pv. allii. Citrus bacterial spot symptoms were induced by X. axonopodis pvs. alfalfae, itrumelo, and allii on Duncan grapefruit and key lime. X. axonopodis pv. allii multiplication and persistence in Duncan grapefruit were equal to those of an aggressive strain of X. axonopodis pv. citrumelo, but populations of X. axonopodis pvs. alfalfae, betlicola, citrumelo, phaseoli, and vesicatoria were 1.3 to 4.0 log units less than X. axonopodis pv. allii in onion. Genomic fingerprinting by repetitive sequence- based polymerase chain reaction demonstrated that X. axonopodis pvs. allii, alfalfae, and citrumelo are distinct from other Xanthomonas species and X. axonopodis pathovars, but these pathovars were indistinguishable from each other. Three genotype groups were apparent among DNA homology group 9.2 strains, and generally correspond to the aggressiveness and genotype groups previously described for X. axonopodis pv. citrumelo. X. axonopodis pvs. allii, alfalfae, and citrumelo appear to have recently diverged from a common ancestral strain.

scholarly journals A taxonomic study of the Spirillum lipoferum group, with descriptions of a new genus, Azospirillum gen. nov. and two species, Azospirillum lipoferum (Beijerinck) comb. nov. and Azospirillum brasilense sp. nov.

1978 ◽  
Vol 24 (8) ◽  
pp. 967-980 ◽  
Author(s):  
Jeffrey J. Tarrand ◽  
Noel R. Krieg ◽  
Johanna Döbereiner
Keyword(s):  
Thermal Denaturation ◽  
New Genus ◽  
Free Medium ◽  
Dna Homology ◽  
Azospirillum Lipoferum ◽  
Dna Base Composition ◽  
Homology Groups ◽  
Group I ◽  
Dna Base ◽  
Group Ii

Sixty-one strains of the root-associated nitrogen fixer Spirillum lipoferum exhibited a similar morphology in peptone–succinate salts medium: vibrioid cells having a diameter of 1.0 μm. When grown in broth the cells had a single polar flagellum, but when grown on agar at 30 °C lateral flagella of shorter wavelength were also formed. The DNA base composition was 69–71 mol % guanine + cytosine when determined by thermal denaturation. DNA homology experiments indicated the occurrence of two distinct but related homology groups: 46 strains were in group I and 15 strains were in group II. Group II strains were distinguished by their ability to use glucose as a sole carbon source for growth in nitrogen-free medium, by their production of an acidic reaction in a peptone-based glucose medium, by their requirement for biotin, and by their formation of wider, longer, S-shaped or helical cells in semisolid nitrogen-free malate medium. The results indicate that two species exist, and on the basis of their characteristics it is proposed that they be assigned to a new genus, Azospirillum. Strains belonging to group II are named A.lipoferum (Beijerinck) comb, nov., while those belonging to group I are named A.brasilense sp. nov. Strain Sp 59b (ATCC 29707) is proposed as the neotype strain for A. lipoferum, and strain Sp 7 (ATCC 29145) is proposed as the type strain for A. brasilense.

Interspecific relationships of antibiotic resistance in Staphylococcus sp.: isolation and comparison of plasmids determining tetracycline resistance in S. aureus and S. epidermidis

1979 ◽  
Vol 25 (12) ◽  
pp. 1468-1475 ◽  
Author(s):  
David J. Groves
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Dna Sequences ◽  
Plasmid Dna ◽  
Tetracycline Resistance ◽  
Cleavage Sites ◽  
Dna Homology ◽  
Reference Plasmid ◽  
High Degree ◽  
Degree Of Similarity

Tetracycline resistance in Staphylococcus aureus and S. epidermidis was confirmed to be determined by plasmids of the same size. Digestion of plasmids from each strain with restriction endonucleases EcoRl, HindIII, and AluI showed a high degree of similarity in their DNA sequences. At least 10 cleavage sites which appear to be common to both plasmids were detected. An additional three cleavage sites appear to be unique to the S. epidermidis plasmid. Further, a survey of recent clinical isolates of tetracycline-resistant staphylococci detected 7 of 10 S. aureus strains and 8 of 9 S. epidermidis strains with plasmids which were of similar size to the purified reference plasmids and which, by hybridization, showed extensive DNA homology to the S. aureus reference plasmid DNA.

scholarly journals Changing patterns among the subgroups of strains of Staphylococcus aureus of phage group II in Danish hospitals from 1961–91

1994 ◽  
Vol 112 (1) ◽  
pp. 81-92 ◽  
Author(s):  
N. H. R. Eriksen ◽  
S. H. Hartzen ◽  
J. Bangsborg ◽  
L. P. Andersen ◽  
V. T. Rosdahl ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Phage Type ◽  
Antibiotic Resistant ◽  
Phage Group ◽  
Phage Types ◽  
Changing Patterns ◽  
Group Ii ◽  
Type Strains ◽  
Observation Period

SummaryDuring the period 1961–91 a total of 567 635 strains of Staphylococcus aureus from hospitalized patients in Denmark have been characterized according to their antibiotic resistance, site of isolation and phage type. Strains of phage group II (typed by the phages 3A, 3C, 55 and 71) have been analysed further. The occurrence of group II strains was relatively constant (approximately 16%) from 1961 until 1983. Since then the frequency of group II strains increased; in 1991 they accounted for 22.7% of all S. aureus strains isolated. Strains of group II can, on the basis of their phage types, be divided in four subgroups: 3A, 71, 71 + and the ‘rest of group II’. Furthermore, within these groups strains may differ from one another in respect to their sensitivity to phages.The increased isolation of group II strains during recent years was because of an increase in strains of subgroups 71 + and the ‘rest of group II strains’. In 1991 these two subgroups accounted for 89.7% of all group II strains. Furthermore, an increasing number of group II strains, 71.4% in 1991, was typable only at RTD × 100. The increase in the number of group II strains was even throughout Denmark. All four subgroups of group II have, during the observation period, become more frequently resistant to penicillin and/or tetracycline. Strains typed at 100 × RTD of subgroup 71 + and the ‘rest of group II’ are more frequently antibiotic resistant than the rest of the group II strains.Strains of the increasing subgroups occurred most often in abscesses.

DNA homology among diverse spiroplasma strains representing several serological groups

1980 ◽  
Vol 26 (11) ◽  
pp. 1356-1363 ◽  
Author(s):  
I.-M. Lee ◽  
R. E. Davis
Keyword(s):  
Dna Sequence ◽  
Sequence Homology ◽  
Dna Homology ◽  
Group Iii ◽  
Molecular Weights ◽  
Group I ◽  
Group Ii ◽  
Corn Stunt Spiroplasma ◽  
Type Strains ◽  
Tulip Tree

Deoxyribonucleic acid (DNA) homology among 10 strains of spiroplasma associated with plants and insects was assessed by analysis of DNA–DNA hybrids with single strand specific S1 nuclease. Based on DNA homology, the spiroplasmas could be divided into three genetically distinct groups (designated I, II, and III), corresponding to three separate serogroups described previously. DNA sequence homology between the three groups was ≤5%. Based on DNA homology, group I could be divided into three subgroups (A, B, and C) that corresponded to three serological subgroups of serogroup I. Subgroup A contained Spiroplasma citri strains Maroc R8A2 and C 189; subgroup B contained strains AS 576 from honey bee and G 1 from flowers; subgroup C contained corn stunt spiroplasma strains 1-747 and PU 8-17. There was 27–54% DNA sequence homology among these three subgroups. Group II contained strains 23-6 and 27-31 isolated from flowers of tulip tree (Liriodendron tulipifera L.). Group III contained strains SR 3 and SR 9, other isolates from flowers of tulip tree. Based on thermal denaturation, guanine plus cytosine contents of DNA from five type strains representing all groups and subgroups were estimated to be close to 26 mol% for group I strains, close to 25 mol% for group II strains, and close to 29 mol% for group III strains. The genome molecular weights of these five type strains were all estimated to be about 109.

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