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991.
992.
运用ISSR分子标记对24份接骨木属植物的遗传距离、亲缘关系进行分析。13条ISSR引物共扩增出3061条可统计条带,其中多态性条带3059个,多态位点百分率高达99.93%,表明接骨木属植物遗传多样性非常丰富。依据ISSR扩增结果,利用NTSYS-pc2.1e软件进行分析,24份接骨木样本的遗传相似系数在0.6772~0.8578。经UPGMA聚类分析,24份接骨木属植物分为2大类,国内接骨木优良单株聚类分析结果与其果实性状的相关性不显著;“金羽”接骨木与国内接骨木聚为一类,亲缘关系较近。 相似文献
993.
试验采用SNP(单核苷酸多态性)技术对贵阳花溪古茶树资源的遗传多样性、群体结构和遗传进化进行了分析.结果表明,利用生物信息学分析古茶树样品的重测序数据,获得了1 656 258个SLAF标签,古茶树样品平均测序深度为24.21x,其中多态性的SLAF标签有462 897个,共得到283 376个高一致性的群体SNP标记.从基于SNP标记获得的进化树可以看出,来自相近地方的古茶树在进化树上基本上处于相近位置,但是花溪古茶树存在着广泛的遗传变异,主成分分析(PCA)获得了与进化树一致的结果.群体结构分析可清晰地把古茶树资源分为乔木型和灌木型2个类群.乔木型古茶树位于进化树下部,而灌木型古茶树处于进化树上部,表明茶树是由乔木型向灌木型进化的. 相似文献
994.
995.
Andrea Coppi 《Biological conservation》2008,141(8):2000-2011
Although several plants endemic to Corsica and Sardinia are included in various redlists, no attempts have been made to analyse their genetic diversity with molecular techniques. Genus Anchusa occurs with seven taxa in either mountain or coastal habitats of the two islands, but the very restricted range and low population size pose these endemisms in a very precarious conservation status. Highly variable markers (AFLP) were therefore used to analyse the patterns and levels of genetic diversity in a sample of 11 populations from the entire range of the group.Results indicate the separation between a mountain genic pool including Anchusa formosa, Anchusa capellii and Anchusa montelinasana, and four groups of coastal accessions. In spite of small size, mountain taxa show low interpopulation differentiation (Fst = 0.02) and relatively high intrapopulation genetic variation (0.365), while coastal accessions showed on average a stronger differentiation (mean Fst = 0.20) and a lower diversity (0.281), possibly due to higher rates of inbreeding. The particularly low levels of variation found in A. sardoa, A. littorea and A. crispa ssp. maritima from the Coghinas bay are likely due to a historical decrease of populations and to bottleneck events caused by loss of habitat and natural stochastic factors on sand dune ecosystems. While habitat maintenance and regulation of grazing by domestic herbivores should be sufficient to ensure the persistence of the mountain endemics, additional actions of in situ and ex situ conservation are needed for the critically endangered coastal species A. sardoa and A. littorea. A. crispa showed a relatively high variation, especially on Corsica. No correlation between population size and genetic variation was found in the latter species, highlighting the importance of the small patches for its conservation. Also, the genetic separation between subspecies crispa and maritima stresses the need of keeping them distinct in redlists and conservation actions on Sardinia. 相似文献
996.
Mkabwa L. K. Manoko Ronald G. van den Berg Richard M. C. Feron Gerard M. van der Weerden Celestina Mariani 《Genetic Resources and Crop Evolution》2008,55(3):409-418
Two hexaploid species of Solanum sect. Solanum are present in Africa: Solanum scabrum and S. nigrum. Solanum scabrum is a widely cultivated species and is used as a leafy vegetable, as a source of medicine and as a source of ink dye. In previous
studies a wide range of morphological diversity has been reported in this species and in some studies subspecies have been
proposed. Subspecies are also recognized in S. nigrum. However, it has not been established whether or not the morphological differences are reflected at the genomic level. The
present study applies AFLPs to study the genetic diversity in S. scabrum and its relationship to geographical provenance, morphological differences and the possible existence of subspecies within
S. scabrum and S. nigrum. The data obtained were analyzed with cluster analysis (using UPGMA and NJ). The results indicate that the genetic variation
within S. scabrum was higher within accessions than between accessions. Accessions did not cluster according to their geographical provenance,
indicating that accessions from different geographical areas were not significantly different genetically. The clustering
reflected neither morphological differences nor domestication status (cultivated or wild). The morphological differences exhibited
by S. scabrum could be due to selection by farmers for different plant types. The AFLP derived clustering pattern did not segregate the
subspecies recognized in S. scabrum and S. nigrum into separate subclusters. 相似文献
997.
Evaluation of genetic diversity of bread wheat landraces from Pakistan by AFLP and implications for a future collection strategy 总被引:1,自引:0,他引:1
Ryoko Hirano Akira Kikuchi Makoto Kawase Kazuo N. Watanabe 《Genetic Resources and Crop Evolution》2008,55(7):1007-1015
We used amplified-fragment-length polymorphism (AFLP) markers to evaluate genetic variation in a set of bread wheat (Triticum aestivum L.) landraces and improved materials. Landraces collected from different geographic and agro-ecological zones in Pakistan
in 1987, 1989 and 1991 were separated into two groups based on their geographic origins: northern (Himalaya) and south-western
(Balochistan) Pakistan. Six AFLP primer combinations detected 453 AFLP markers in the 43 landrace accessions and four high-yield
varieties (HYVs). Of these, 225 (49.67%) were rare (shared with < 5% of all accessions). Among these rare alleles, 23 (10.22%)
were common in the Himalaya (shared with > 10% of accessions collected there) but were not found in Balochistan. We conclude
that there is a higher probability of collecting rare alleles at overall, but which are in contrast locally common ones in
the Himalayan region. Gene diversity was 0.17 in the Himalayan group and 0.15 in the Balochistan group. Considerable genetic
variability was found in both groups. Accessions from different agro-ecological zones were indistinguishable by cluster analysis,
indicating intensive seed trading within the country. Cluster analysis indicated that the landraces and the HYVs are genetically
distinct; suggesting that genetic erosion of wheat landraces has been unlikely taken in place. This study provides an example
of how analysis of existing materials and data, can serve as a basis for future collection planning and conservation policies. 相似文献
998.
Kim N. Hamilton Sarah E. Ashmore Rod A. Drew 《Genetic Resources and Crop Evolution》2008,55(5):683-693
The comparative morphology of the seeds of three Australian Citrus species, C. australasica C. inodora and C. garrawayi, was studied. Their seed characteristics were broadly similar to those of the cultivated species of the genus, when observed
under light and scanning electron microscopy. Citrus garrawayi differed in seed shape (rounded to triangular) and seed coat morphology (i.e., thicker with longer epidermal protrusions)
from C. australasica and C. inodora (rounded surface with flat underside in shape). The well-developed minute epidermal protrusions on the seed coat of C. garrawayi were more similar to those in the cultivated species, C. × sinensis and C. × aurantium. In contrast, the surface topography of C. australasica and C. inodora seeds was more like that of the cultivated species, C. × aurantifolia and C. × limon. Seed morphology, especially surface topography, was found to be a useful tool for taxonomic identification in Australian
wild citrus. 相似文献
999.
1000.