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Публикации с 1 по 12 из 12 всего
Просмотров: 325 Rating Star
Филогенетическое исследование пихт (Abies Mill.) проведено с использованием нуклеотидных по следовательностей нескольких регионов хлоропластной ДНК общей длиной 5580 пн и включало в себя 37 таксонов, представляющих основные линии эволюции рода, а также Keteleeria davidiana. От мечено, что согласн...о филогенетической реконструкции виды Abies разделились на шесть основных групп, в целом соответствующих их географическому распространению. Обнаружено, что дерево имеет три базальные клады, все они содержат американские виды и только одна – евроазиатские. Калибровки времени дивергенции, основанные на палеоботанических данных и на оценке скоро сти мутирования хлоропластной ДНК у Pinaceae, дали близкие результаты. Возраст диверсифика ции среди базальных клад современных Abies оценен как конец олигоцена–начало миоцена, воз раст отделения средиземноморской ветви от азиатскосевероамериканской – как миоцен, возраст диверсификации внутри “молодых” групп (средиземноморских, азиатских и “бореальных” амери канских пихт (A. lasiocarpa, A. balsamea, A. fraseri)) – как плиоцен–плейстоцен. На основе получен ной филогенетической реконструкции предложены наиболее вероятные биогеографические сцена рии. Отмечено, что существующие систематические классификации Abies находятся в серьезном противоречии с филогенетической реконструкцией и требуют ревизии.
Подробнее Год издания: 2014
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
Просмотров: 283 Rating Star
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
Molecular Phylogenetic Analysis of the Genus Abies (Pinaceae) Based on the Nucleotide Sequence of Chloroplast DNA
Просмотров: 276 Rating Star
A phylogenetic study of firs (Abies Mill.) was conducted using nucleotide sequences of several chloroplast DNA regions with a total length of 5580 bp. The analysis included 37 taxa, which represented the main evolutionary lineages of the genus, and Keteleeria davidiana. According to phylogenetic re...construction, the Abies species were subdivided into six main groups, generally corresponding to their geographic distribu tion. The phylogenetic tree had three basal clades. All of these clades contained American species, and only one of them contained Eurasian species. The divergence time calibrations, based on paleobotanical data and the chloroplast DNA mutation rate estimates in Pinaceae, produced similar results. The age of diversification among the basal clades of the presentday Abies was estimated as the end of the Oligocene–beginning of Miocene. The age of the separation of Mediterranean firs from the Asian–North American branch corre sponds to the Miocene. The age of diversification within the young groups of Mediterranean, Asian, and “boreal” American firs (A. lasiocarpa, A. balsamea, A. fraseri) was estimated as the Pliocene—Pleistocene. Based on the phylogenetic reconstruction obtained, the most plausible biogeographic scenarios were sug gested. It is noted that the existing systematic classification of the genus Abies strongly contradicts with phy logenetic reconstruction and requires revision.
Подробнее Год издания: 2014
Genetic Differentiation of Spruce Populations in Northwest Russia According to the Results of Microsatellite Loci Analysis
Просмотров: 389 Rating Star
Analysis of the genetic diversity of the spruce populations in the northwest of the European part of Russia using microsatellite markers revealed two relatively isolated genetic clusters. One of them is com posed of trees that were identified as P. abies according to morphological traits. Another ...cluster unites spruces that were determined as P. obovata and P. fennica. The results of SSR analysis do not support the idea of the taxonomic independence of the hybridogeneous P. fennica species. The frequency of genotypes attributed to P. abies (according to the results of microsatellite markers) decreases significantly from south to north.
Подробнее Год издания: 2013
Просмотров: 286 Rating Star
Анализ генетического разнообразия популяций ели на Северо-Западе Европейской части России с использованием микросателлитных маркеров выявил два относительно обособленных генетических кластера. Один из них составляют деревья, идентифицированные по морфологическим признакам как P.abies. Другой класте...р объединяет ели, определенные как P.obovata и P.fennica. Результаты SSR-анализа не поддерживают идею о таксономической самостоятельности гибридогенного вида P.fennica. Частота встречаемости генотипов, отнесенных по результатам микросателлитного маркирования к P.abies, достоверно убывает с юга на север.
Подробнее Год издания: 2015
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
Просмотров: 263 Rating Star
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
Morphological, anatomical and genetic differentiation of Cornus mas, Cornus officinalis and their interspecific hybrid
Просмотров: 277 Rating Star
Cornus mas L., C. officinalis Sieb. et Zucc. and their putative interspecific hybrid specimens were examined in order to describe their morphological, anatomical and genetic differentiation. Petiole length, number of leaf veins, pedicel and bract length, stone size, thickness of pericarp layers, th...e size and number of locules and the number of cavities were measured. Pedicels and bracts were shown to be significantly longer for C. mas (7.22 and 6.95 mm) and for the putative hybrid (9.11 and 6.61 mm) than for C. officinalis (6.86 and 5.81 mm, respectively). Average values of stone width and thickness, exocarp and mesocarp thickness, the number of cavities in the endocarp obtained for the putative hybrid differed significantly in comparison to C. mas and were similar to C. officinalis. Genotypes of the examined species were evaluated for genetic relationships using random amplified polymorphic DNA (RAPD) markers. Initial screening of the bulks of C. mas and C. officinalis compared with their putative hybrid using 72 decamer random primers resulted in the identification of 24 primers differentiating both species and their putative hybrid and showing reliable polymorphisms. Among a total of 485 amplified fragments, 89.7% were polymorphic, 18.8% were specific to C. mas individuals, and 18.6% were specific to the individuals of C. officinalis. In obtained profiles of the examined hybrid individual specific products absent in the genotypes of both parents were observed. The phylogenetic tree revealed two separate clusters including C. mas and C. officinalis accessions, respectively. The biggest genetic distance was observed for hybrid specimens, although the hybrid belonged to the C. mas cluster.
Подробнее Год издания: 2012
Идентификация Picea abies, P. fennica, P. obovata (Pinaceae) и их форм с помощью методов молекулярного маркирования
Просмотров: 387 Rating Star
В 2009 г. в Тосненском р-не Ленинградской обл. проведены исследования географических культур Picea abies, P. obovata и P. fennica, выращенных из семян, собранных в разных регионах европейской части России и Зап. Сибири. Для ели финской выявлены формы с признаками ели европейской {P. fennica, близка...я P. abies) и с признаками ели сибирской {P. fennica, близкая P. obovata). На материале 67 генотипов елей географических культур, относящихся к 26 климатипам, проанализированы возможности молекулярных маркеров RAPD для целей диагностики видов P. abies, Р. obovata и P. fennica. Выявлен потенциально диагностический RAPD-маркер OPD1430o, ранее уже упоминавшийся в литературе, как эффективный для диагностики близкородственных видов североамериканских елей. Маркер OPDM300 может быть использован для диагностики P. abies, P. obovata и близких к ним форм P. fennica в спорных случаях.
Подробнее Год издания: 2012
Современные подходы к разработке электронных определителей биологических объектов
Просмотров: 280 Rating Star
Электронный определитель - это программный или программно-аппаратный комплекс для диагностики таксономической принадлежности биологических объектов, а также идентификации объектов неживой природы, либо антропогенного происхождения с применением ЭВМ. Первые опыты использования электронных определите...лей биологических объектов – середина 1960-х годов.
Подробнее Год издания: 2014
Катаевские чтения 2013 - определитель дендрофильных насекомых
Просмотров: 337 Rating Star
Электронный определитель - это программный или программно-аппаратный комплекс для диагностики таксономической принадлежности биологических объектов, а также идентификации объектов неживой природы, либо антропогенного происхождения с применением ЭВМ....
Подробнее Год издания: 2013