Авторы -> Lascoux M.  (3)

Все публикации автора:
Nuclear and cytoplasmic genetic diversity reveals long-term population decline in Abies semenovii, an endemic fir of central Asia
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The genus Abies is one of the largest conifer genera and many of the marginal species remain poorly characterized. Abies semenovii B. Fedtsch. is a rare mountain fir species from central Asia, and its species status is still disputed. We used both nuclear (allozymes and AFLP) and chloroplastic (cpS...SR) markers to show that A. semenovii deserves to be considered as a species and that its low genetic diversity justifies more a proactive conservation policy. First, A. semenovii was significantly differentiated from the Siberian fir Abies sibirica Ledeb. and we did not detect gene flow between the two species. Second, A. semenovii has a very low nuclear genetic diversity, suggesting a prolonged restricted effective population size. Abies semenovii had low cpSSR diversity too but the identification of seven closely related haplotypes suggests that these mutations accumulated recently during a phase of population expansion. This agrees well with the palynological record and is in contrast with the situation observed in another rare Eurasian fir endemic to Kamchatka, Abies gracilis Kom., which was devoid of variation in cpSSRs but that also had a more substantial nuclear marker diversity than A. semenovii, thereby suggesting a more recent but less severe population bottleneck.
Подробнее Год издания: 2012
Post-glacial history and introgression in Abies (Pinaceae) species of the Russian Far East inferred from both nuclear and cytoplasmic markers
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The main aim of the present study is to infer the post-glacial history of Abies species from north-east Asia and to test the hypotheses that coastal Abies populations suffered less from climatic fluctuations during Pleistocene glacial periods than their more continental counterparts, and that Sakha...lin was a major area of introgression.
Подробнее Год издания: 2011
Southern montane populations did not contribute to the recolonization of West Siberian Plain by Siberian larch (Larix sibirica): a range-wide analysis of cytoplasmic markers
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While many species were confined to southern latitudes during the last glaciations, there has lately been mounting evidence that some of the most cold-tolerant species were actually able to survive close to the ice sheets. The contribution of these higher latitude outposts to the main recolonizatio...n thrust remains, however, untested. In the present study, we use the first range-wide survey of genetic diversity at cytoplasmic markers in Siberian larch (Larix sibirica; four mitochondrial (mt) DNA loci and five chloroplast (cp) DNA SSR loci) to (i) assess the relative contributions of southern and central areas to the current L. sibirica distribution range; and (ii) date the last major population expansion in both L. sibirica and adjacent Larix species. The geographic distribution of cpDNA variation was uninformative, but that of mitotypes clearly indicates that the southernmost populations, located in Mongolia and the Tien-Shan and Sayan Mountain ranges, had a very limited contribution to the current populations of the central and northern parts of the range. It also suggests that the contribution of the high latitude cryptic refugia was geographically limited and that most of the current West Siberian Plain larch populations likely originated in the foothills of the Sayan Mountains. Interestingly, the main population expansion detected through Approximate Bayesian Computation (ABC) in all four larch species investigated here pre-dates the LGM, with a mode in a range of 220 000–1 340 000 years BP. Hence, L. sibirica, like other major conifer species of the boreal forest, was strongly affected by climatic events pre-dating the Last Glacial Maximum.
Подробнее Год издания: 2013