Optimization of RAPD-PCR Fingerprinting to Analyse Genetic Variation Within Populations ofFusarium oxysporumf.sp.cubense

The abundance of the Australian inoculant strain of Rhizobium leguminosarum bv. trifolii for subterraneum clover (WU95) and the diversity of naturalised rhizobia were assessed in 3 subterranean clover pastures in the Albany region of south-western Western Australia. Most probable number, enzyme linked immunosorbent assay (ELISA), and polymerase chain reaction (PCR) techniques were used. A putative strain similar to inoculant strain WU96 was uncommon at one site (South Stirling) and not isolated at 2 other sites. Randomly amplified polymorphic DNA (RAPD) PCR fingerprinting using the RPO1 primer identified 45 different profiles amongst the 208 isolates examined. RAPD-PCR fingerprinting using the primers RPO4 and RPO5 confirmed most groupings based on RPO1 fingerprint patterns and revealed further genetic diversity within some groups. Overall, 54 putative strains were defined by RAPD-PCR fingerprint profiles across the 3 sites. Subterranean clover rhizobia at the Manypeaks and Mount Shadforth sites were dominated by isolates with 1 or 2 RPO1 RAPD profiles at 2 sampling times, while the population at South Stirling was much more diverse. The symbiotic effectiveness of 11 rhizobial isolates, representing the major RPO1 RAPD profile groups within naturalised rhizobial populations, were compared in pot culture with those of the 2 commercial inoculant strains for subterranean clover, WU95 and TA1, on 3 cultivars. Differences in effectiveness among 3 of the 11 isolates were observed in comparison to both the commercial strains and other naturalised isolates. The nitrogen fixing effectiveness of 8 isolates representing different subgroups from one RP01 group was not the same. The use of all 3 primers increased the precision in defining putative strains of Rhizobium leguminosarum bv. trifolii, and although naturalised rhizobia from these pastures are saprophytically competent, their dominance in nodules does not appear to be linked to symbiotic effectiveness.

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Analysis of genetic variation and differentiation in the pygmy wood mouse Sylvaemus uralensis (Rodentia, Muridae) aided by the RAPD-PCR method

Biology Bulletin ◽

10.1134/s1062359009030030 ◽

2009 ◽

Vol 36 (3) ◽

pp. 227-241 ◽

Cited By ~ 9

Author(s):

A. S. Bogdanov ◽

D. M. Atopkin ◽

G. N. Chelomina

Keyword(s):

Genetic Variation ◽

Wood Mouse ◽

Pygmy Wood Mouse ◽

Rapd Pcr ◽

Pcr Method

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Genetic Variation of Sinorhizobium meliloti Isolates Differing in Their Ability to Drought Tolerance

Journal of Biotechnology Research Center ◽

10.24126/jobrc.2015.9.2.427 ◽

2015 ◽

Vol 9 (2) ◽

pp. 7-22

Author(s):

Rana A. Hameed Hameed ◽

Nidhal N. Hussain Hussain ◽

Abed aljasim M. Aljibouri Aljibouri

Keyword(s):

Genetic Diversity ◽

Cluster Analysis ◽

Genetic Variation ◽

Soil Bacteria ◽

Sinorhizobium Meliloti ◽

Forage Crop ◽

Drought Tolerant ◽

Rapd Pcr ◽

Tolerance Study ◽

Polyethylene Glycol 6000

Soil bacteria Sinorhizobium meliloti had enormous agricultural value, due to their ability infixing nitrogen symbiotically with an important forage crop legume- alfalfa. The aim of thisstudy (i) isolate indigenous S. meliloti from different field sites in Iraq, (ii) evaluate the isolatestolerance to induce drought using polyethylene glycol-6000, (iii) assessing genetic diversity andgenetic relationships among isolates of natural population with drought tolerant abilities.Drought tolerance study revealed vast variations between Sinorhizobium isolates, the highesttolerant isolates to drought were twelve from total thirty 40%, tolerated from -3 up to -4 Mpa(mega pascal), while the drought sensitive isolates tolerated upto – 1.5 Mpa, except isolate Bs58which tolerated upto -1 Mpa water potential. The growth declined with the increase of droughtstress. Cluster analysis based on RAPD-PCR showed significant differences among S. melilotiisolates, and the results gave almost identical grouping of isolates in regards to droughtexperiment. Among indigenous isolates two divergent groups could be determined, the first majorgroup included drought tolerant isolates and the second major group comprised all droughtmoderate and sensitive isolates with 40% similarity between the two major groups.

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PCR-Based Genotyping of Epidemic and PreepidemicTrichoderma Isolates Associated with Green Mold ofAgaricus bisporus

Applied and Environmental Microbiology ◽

10.1128/aem.65.6.2674-2678.1999 ◽

1999 ◽

Vol 65 (6) ◽

pp. 2674-2678 ◽

Cited By ~ 21

Author(s):

X. Chen ◽

C. P. Romaine ◽

Q. Tan ◽

B. Schlagnhaufer ◽

M. D. Ospina-Giraldo ◽

...

Keyword(s):

Genetic Variation ◽

North America ◽

Agaricus Bisporus ◽

Rapd Markers ◽

Rapd Analysis ◽

Pcr Amplification ◽

Green Mold ◽

Rapd Pcr ◽

Cultivated Mushroom ◽

Highly Virulent

ABSTRACT We used randomly amplified polymorphic DNA (RAPD)-PCR to estimate genetic variation among isolates of Trichoderma associated with green mold on the cultivated mushroom Agaricus bisporus. Of 83 isolates examined, 66 were sampled during the recent green mold epidemic, while the remaining 17 isolates were collected just prior to the epidemic and date back to the 1950s.Trichoderma harzianum biotype 4 was identified by RAPD analysis as the cause of almost 90% of the epidemic-related episodes of green mold occurring in the major commercial mushroom-growing region in North America. Biotype 4 was more closely allied to T. harzianum biotype 2, the predominant pathogenic genotype in Europe, than to the less pathogenic biotype 1 and Trichoderma atroviride (formerly T. harzianum biotype 3). No variation in the RAPD patterns was observed among the isolates within biotype 2 or 4, suggesting that the two pathogenic biotypes were populations containing single clones. Considerable genetic variation, however, was noted among isolates of biotype 1 and T. atroviride from Europe. Biotype 4 was not represented by the preepidemic isolates of Trichoderma as determined by RAPD markers and PCR amplification of an arbitrary DNA sequence unique to the genomes of biotypes 2 and 4. Our findings suggest that the onset of the green mold epidemic in North America resulted from the recent introduction of a highly virulent genotype of the pathogen into cultivated mushrooms.

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