5 research outputs found
AN INSIGHT IN SOME POPULATION FEATURES OF XANTHOMONAS ARBORICOLA pv. JUGLANDIS
Xanthomonas arboricola pv. juglandis (Xaj) is the causal agent
of bacterial blight of walnut, an emerging disease, which has the
potential to severely affect walnut orchards. An Italian strain collection
of Xaj, obtained during the past 3 years from affected orchards
in Romagna, was first assayed with conventional PCR with
XajF/XajR primer pair developed to confirm strain identity. The
population structure of the collection of Xaj isolates, confirms the
presence of different genetic groups identified by rep-PCR (using Italian collection are currently being analysed by MLSA (multi
locus sequence analysis), using 7 primers for 7 different housekeeping
genes, with the purpose to better characterise the Italian
isolates for phylotyping. The study of copper resistance on a wide
collection of over 150 Xaj strains frequently showed high resistance
(up to 500 ppm Cu++): two strains have been further studied
confirming the presence of chromosomal genes copA and copB involved
in the general copABCD copper resistance structure, as
described for Pseudomonas syringae. Sequencing and comparing
with other Xanthomonads were done. The elucidation of Xaj
population structure may help to deeper investigate some additional
aspects of the molecular epidemiology of the disease, thus
allowing a better control strategy in the field.
the REP, BOX and ERIC primers) and by multilocus sequence
typing (MLST) and multilocus variable number analysis of tandem
repeat (MLVA). Xaj and Xaj-like bacterial isolates from th
Genetic diversity and population structure analyses in the Alpine plum (Prunus brigantina Vill.) confirm its affiliation to the Armeniaca section
In-depth characterization of the genetic diversity and population structure of wild relatives is of paramount importance for genetic improvement and biodiversity conservation, and is particularly crucial when the wild relatives of crops are endangered. In this study, we sampled the Alpine plum (Briançon apricot) Prunus brigantina Vill. across its natural distribution in the French Alps, where its populations are severely fragmented and its population size strongly impacted by humans. We analysed 71 wild P. brigantina samples with 24 nuclear simple sequence repeat (microsatellite) markers and studied their genetic diversity and population structure, with the aim to inform in situ conservation measures and build a core collection for long-term ex situ conservation. We also examined the genetic relationships of P. brigantina with other species in the Prunophora subgenus, encompassing the Prunus (Eurasian plums), Prunocerasus (North American plums) and Armeniaca (apricots) sections, to check its current taxonomy. We detected a moderate genetic diversity in P. brigantina and a Bayesian model–based clustering approach revealed the existence of three genetically differentiated clusters, endemic to three geographical regions in the Alps, which will be important for in situ conservation measures. Based on genetic diversity and population structure analyses, a subset of 36 accessions were selected for ex situ conservation in a core collection that encompasses the whole detected P. brigantina allelic diversity. Using a dataset of cultivated apricots and wild cherry plums (P. cerasifera) genotyped with the same markers, we detected gene flow neither with European P. armeniaca cultivars nor with diploid plums. Similar to previous studies, dendrograms and networks placed P. brigantina closer to the Armeniaca section than to the Prunus section. Our results thus confirm the classification of P. brigantina within the Armeniaca section; it also illustrates the importance of the sampling size and design in phylogenetic studies.ADAPTATION DES CULTURES FRUITIÈRES AU CHANGEMENT CLIMATIQUE DANS LE BASSIN MÉDITERRANÉE
Genetic diversity and population structure analyses in the Alpine plum ( Prunus brigantina Vill.) confirm its affiliation to the Armeniaca section
In-depth characterization of the genetic diversity and population structure of wild relatives of crops is of paramount importance for genetic improvement and biodiversity conservation, and is particularly crucial when the wild relatives of crops are endangered. In this study, we therefore sampled the Alpine plum (Briançon apricot) Prunus brigantina Vill. across its natural distribution in the French Alps, where its populations are severely fragmented and its population size strongly impacted by humans. We analysed 71 wild P. brigantina samples with 34 nuclear markers and studied their genetic diversity and population structure, with the aim to inform in situ conservation measures and build a core collection for long-term ex-situ conservation. We also examined the genetic relationships of P. brigantina with other species in the Prunophora subgenus, encompassing the Prunus (Eurasian plums), Prunocerasus (North-American plums) and Armeniaca (apricots) sections, to check its current taxonomy. We detected a moderate genetic diversity in P. brigantina and a Bayesian model-based clustering approach revealed the existence of three genetically differentiated clusters, endemic to three geographical regions in the Alps, which will be important for in situ conservation measures. Based on genetic diversity and population structure analyses, a subset of 36 accessions were selected for ex-situ conservation in a core collection that encompasses the whole detected P. brigantina allelic diversity. Using a dataset of cultivated apricots and wild cherry plums ( P. cerasifera ) genotyped with the same markers, we detected gene flow neither with European P. armeniaca cultivars nor with diploid plums. In contrast with previous studies, dendrograms and networks placed P. brigantina closer to Armeniaca species than to Prunus species. Our results thus confirm the classification of P. brigantina within the Armeniaca section; it also illustrates the importance of the sampling size and design in phylogenetic studies
Draft Genome Sequence of the Xanthomonas cassavae Type Strain CFBP 4642.
International audienceWe report the draft genome sequence of the Xanthomonas cassavae type strain CFBP 4642, the causal agent of bacterial necrosis on cassava plants. These data will allow the comparison of this nonvascular pathogen with the vascular pathogen Xanthomonas axonopodis pv. manihotis, both infecting the same host, which will facilitate the development of diagnostic tools
High-Quality Draft Genome Sequences of Xanthomonas axonopodis pv. glycines Strains CFBP 2526 and CFBP 7119.
International audienceWe report here the high-quality draft genome sequences of two strains of Xanthomonas axonopodis pv. glycines, the causal agent of bacterial pustule on soybeans. Comparison of these genomes with those of phylogenetically closely related pathovars of Xanthomonas spp. will help to understand the mechanisms involved in host specificity and adaptation to host plants