Genetic diversity and geographic distribution of parasitic flies of the Philornis torquans complex in Argentina

ABSTRACT The genetic diversity of lactococci isolated from raw milk in the Camembert cheese Registered Designation of Origin area was studied. Two seasonal samples (winter and summer) of raw milk were obtained from six farms in two areas (Bessin and Bocage Falaisien) of Normandy. All of the strains analyzed had a Lactococcus lactis subsp.lactis phenotype, whereas the randomly amplified polymorphic DNA (RAPD) technique genotypically identified the strains as members of L. lactis subsp. lactis orL. lactis subsp. cremoris. The genotypes were confirmed by performing standard PCR with primers corresponding to a region of the histidine biosynthesis operon. The geographic distribution of each subspecies of L. lactis was determined; 80% of the Bocage Falaisien strains were members ofL. lactis subsp. lactis, and 30.5% of the Bessin strains were members of L. lactis subsp.lactis. A dendrogram was produced from a computer analysis of the RAPD profiles in order to evaluate the diversity of the lactococci below the subspecies level. The coefficient of similarity for 117 of the 139 strains identified as members of L. lactis subsp.cremoris was as high as 66%. The L. lactis subsp. lactis strains were more heterogeneous and formed 10 separate clusters (the level of similarity among the clusters was 18%). Reference strains of L. lactissubsp. lactis fell into 2 of these 10 clusters, demonstrating that lactococcal isolates are clearly different. As determined by the RAPD profiles, some L. lactis subsp.lactis strains were specific to the farms from which they originated and were recovered throughout the year (in both summer and winter). Therefore, the typicality of L. lactissubsp. lactis strains was linked to the farm of origin rather than the area. These findings emphasize the significance of designation of origin and the specificity of “Camembert de Normandie” cheese.

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Genetic Diversity and Geographic Distribution of Genetically Distinct Rabies Viruses in the Philippines

PLoS Neglected Tropical Diseases ◽

10.1371/journal.pntd.0002144 ◽

2013 ◽

Vol 7 (4) ◽

pp. e2144 ◽

Cited By ~ 13

Author(s):

Mariko Saito ◽

Hitoshi Oshitani ◽

Jun Ryan C. Orbina ◽

Kentaro Tohma ◽

Alice S. de Guzman ◽

...

Keyword(s):

Genetic Diversity ◽

Geographic Distribution ◽

The Philippines

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Morpho-phenological diversity among Tunisian natural populations of Brachypodium hybridum

The Journal of Agricultural Science ◽

10.1017/s0021859614000689 ◽

2014 ◽

Vol 153 (6) ◽

pp. 1006-1016 ◽

Cited By ~ 5

Author(s):

M. NEJI ◽

F. GEUNA ◽

W. TAAMALLI ◽

Y. IBRAHIM ◽

M. SMIDA ◽

...

Keyword(s):

Genetic Diversity ◽

Geographic Distribution ◽

Phenotypic Diversity ◽

Average Length ◽

Natural Populations ◽

Negative Relationship ◽

Mantel Test ◽

Population Variation ◽

Long Distance ◽

Temperate Cereal

SUMMARYBrachypodium hybridum belongs to the Poaceae grass subfamily. It has a close genetic relationship with temperate cereal crops, which means that it can be used as a model for temperate cereal and grass crops. In order to improve knowledge on the genetic diversity of this species, 145 lines of B. hybridum representative of nine populations and all the ecoregions of Tunisia were characterized on the basis of 18 morpho-phenologic features. The results show a considerable variation between populations and ecoregions in all traits studied. Variation was relatively higher for reproductive than vegetative traits. The majority of traits showed very low to high heritability with low border value for average length of spikelet (ALS) and an average value of 0·64. It is noticeable that high values of heritability were observed for most vegetative descriptors, with low values for reproductive ones. Differentiation between populations (QST) varied from 0·02 for ALS to 0·78 for average length of leaves with a mean value across traits of 0·4, which confirms the wide intra-population variation in Tunisian natural population of B. hybridum. Pairwise QST showed that the greatest differentiation among populations was registered between Ain Drahem and Jbel Zaghouan and the smallest between Haouria and Raoued. Overall, the Ain Draham population showed the largest differentiation from the rest of the populations. To infer the effect of geographic distribution of the species, a Mantel test was applied between observed pairwise differentiation and geographic distance between populations and between ecoregions: the results show a positive, but not significant, relationship. In addition a significant negative relationship was found between phenotypic diversity and altitude, indicating that genetic diversity decreased with increasing altitude. Taken together, the high levels of intra-population variation and the lack of correlation between genetic differentiation and geographic distribution suggest a potentially important rate of long-distance seed dispersal and confirm the role played by natural selection in the population structure of Tunisian natural populations of B. hybridum.

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