The present study was conducted to assess the molecular characterization and genetic diversity amongst natural populations of Myrica rubra in Guangxi Zhuang Autonomous Region, China, thus to provide scientific evidenc...The present study was conducted to assess the molecular characterization and genetic diversity amongst natural populations of Myrica rubra in Guangxi Zhuang Autonomous Region, China, thus to provide scientific evidence for germplasm conservation and exploitation. Using ISSR （inter-simple sequence repeats） markers, the level of genetic variation and the molecular characterization of 10 natural populations of M. rubra, originated from Guangxi Zhuang Autonomous Region in China, were performed. Based on 11 primers, 123 clear and reproducible DNA fragments were generated, of which 95 （77.24%） were polymorphic. The average value of Nei＇s gene diversity （He） was 0.268. The coefficient of genetic differentiation （Gst） was 0.341, revealing that 34.1% of the total molecular variance existed among populations. The Mantel statistical testing showed that the genetic distance was correlated to the geographic distance, but the correlation was not significant. Ten populations were divided into two big clusters according to unweighted pair group method with arithmetic mean （UPGMA） analysis. One consisted of populations of Rongxian （RX）, Hepu （HP）, Liangqing （LQ）, Marshan （MS）, Lingshan （LS） and Shansi （SS）, which originated from the southern Guangxi, while the other was composed of Guanyang （GY） and Lingui （LG） populations of northern Guangxi, Huanjiang （HJ） populations of northwestern Guangxi and Shanglin （SL） populations of southern Guangxi. The level of genetic variation in wild M. rubra population distributed in Guangxi is high. Gene drift within the population was responsible for genetic variation in wild M. rubra in Guangxi, and the effect of the genetic flow among inter-populations was not significant. Classification of wild M. rubra populations was correlated to climate and environment. The molecular characterization and diversity assessment of M. rubra is of immense value for planning conservation of its genetic resources and their exploitation for further studies.展开更多
North China Mountain Walnut (NCMW) is one of the ancestors of extant cultivated species, and a valuable gene resource for resistance breeding of walnut in China. Inter-Simple Sequence Repeat (ISSR) primers were design...North China Mountain Walnut (NCMW) is one of the ancestors of extant cultivated species, and a valuable gene resource for resistance breeding of walnut in China. Inter-Simple Sequence Repeat (ISSR) primers were designed to evaluate the level and pattern of genetic diversity in eight populations of NCMW. Nine ISSR primers yielded 91 amplification products with different sizes, of which 84 (92.31%) were polymorphic. A high species-level genetic diversity was detected with Nei’s (H = 0.2592) and Shannon’s diversity (I = 0.4003). In contrast, the population-level genetic diversity was relatively lower (PPB = 43.27%, H = 0.1347, I = 0.1862). Coefficient of populations differentiation (GST) was 0.5066, indicating that inter-population and intra-population variation contributed 50.66% and 49.34% respectively to the total genetic variability. This relative level of variation was further supported by AMOVA analysis. Limited gene flow (Nm = 0.5133.), habitat fragmentation and geographical isolation might be responsible for the population structure of NCMW. UPGMA cluster analysis classified the eight populations into three groups which showed no significant relationship between the genetic similarity coefficient and geographic origin but showed remarkable association with morpho-physiological characters, particularly nut traits. The results of the study provide species-level and population-level genetic profiles for further exploitation and conservation of genetic diversity of NCMW.展开更多
Morningglories (Ipomoea spp.) are among the most troublesome weedy species in agroecological environments. Ipomoea lacunosa is one of the most prevalent of these species. Localized adaptations resulted in the evolutio...Morningglories (Ipomoea spp.) are among the most troublesome weedy species in agroecological environments. Ipomoea lacunosa is one of the most prevalent of these species. Localized adaptations resulted in the evolution of several I. lacunosa ecotypes in North America, which could potentially impact its response to crop management practices. To evaluate the genetic diversity and population structure of I. lacunosa populations, we amplified inter-simple sequence repeats loci by polymerase chain reaction (ISSR-PCR) of 64 accessions using 14 ISSR primers for Ipomoea. Of these, 64 polymorphic fragments were scored. Analysis of Nei’s genetic distance (GD) values placed the accessions into four genotypic clusters, two of which were composed primarily of accessions from Arkansas and Mississippi with GD between clusters of 0.318. The overall GD was 0.238, indicating a narrow genetic base. Population structure analysis determined three ancestral subgroups, with the majority of Arkansas and Mississippi accessions separated into two subgroups. The existence of various genotypes and ecotypes of I. lacunosa demonstrates the evolutionary diversification of this weedy species as it adapts to new colonized environments and agricultural activities.展开更多
Ulva pertusa is a native species to Asia along the western coast of Pacific Ocean,with new occurrence records in the eastern coast of Pacific,the northwest coast of Atlantic and the Mediterranean Sea.However,little is...Ulva pertusa is a native species to Asia along the western coast of Pacific Ocean,with new occurrence records in the eastern coast of Pacific,the northwest coast of Atlantic and the Mediterranean Sea.However,little is known about its population genetic structure.In this study,twelve U.pertusa populations from 3 coastal areas of China:Qingdao,Yantai and Dalian,were applied to ISSR analysis.The selected 4 ISSR primers amplified 120 polymorphic bands totally.Nei's gene diversity (H) ranged from 0.0729 to 0.1496,and Shannon's information index (I) ranged from 0.1072 to 0.2196.Genetic diversity was greater within Qingdao populations (H=0.2069,I=0.3232).Analysis of molecular variance (AMOVA) showed the greatest variance within populations (68.57%),much less variance among populations (22.63%) and among areas (8.79%).Unweighted pair-group mean analysis (UPGMA) indicated that clustering of U.pertusa individuals mainly relates to their populations and geographic distances separating those populations.Genetic differentiation and limited gene flow among U.pertusa populations were indicated by ISSR analysis.展开更多
采用ISSR标记方法,对南方红豆杉〔Taxus chinensis(Pilger)Rehd.var.mairei(Lemée et Lévl.)Cheng et L.K.Fu〕3个野生种群(包括江西黄港和黄沙种群以及福建枫溪种群)、2个迁地保护栽培种群及2个迁地保护衍生种群(均位于江苏...采用ISSR标记方法,对南方红豆杉〔Taxus chinensis(Pilger)Rehd.var.mairei(Lemée et Lévl.)Cheng et L.K.Fu〕3个野生种群(包括江西黄港和黄沙种群以及福建枫溪种群)、2个迁地保护栽培种群及2个迁地保护衍生种群(均位于江苏南京中山植物园和江西庐山植物园)的遗传多样性和遗传结构进行了分析和比较。结果显示:用8个引物从南方红豆杉的基因组总DNA中共扩增出73条带,其中多态性条带62条。2个迁地保护衍生种群的多态性条带百分率(PPB)、Nei’s多样性指数(h)和Shannon信息指数(I)较高,3个野生种群的PPB、h和I值总体上居中,而2个迁地保护栽培种群的PPB、h和I值较低。合并后的迁地保护衍生种群以及野生种群均有较高的遗传多样性,二者的PPB、h和I值相近,分别为78.08%和82.19%、0.207 6和0.205 8、0.322 9和0.325 9;但二者的遗传结构存在差异,迁地保护衍生种群的遗传分化系数(GST)为0.068 9,明显低于野生种群(0.168 5)。合并后的迁地保护栽培种群的遗传多样性相对较低,PPB、h和I值分别为60.27%、0.180 7和0.275 2;而GST值最高(0.251 4),明显高于合并后的野生种群和迁地保护衍生种群。研究结果表明:在植物园次生林环境条件下,回归到自然生境下的南方红豆杉迁地保护衍生种群的遗传多样性趋于丰富并接近野生种群,从而证明了植物园在濒危植物迁地保护中具有以往未被认识到的巨大潜力。展开更多
采集戴云山脉自然群体的41份野生杨梅样品为材料,采用ISSR分子标记结合相关软件进行遗传结构分析。研究结果表明:筛选的13条引物共扩增获得175条DNA条带,其中多态性条带为140条,占扩增总片段的80%,表明戴云山野生杨梅具有较高的遗传多...采集戴云山脉自然群体的41份野生杨梅样品为材料,采用ISSR分子标记结合相关软件进行遗传结构分析。研究结果表明:筛选的13条引物共扩增获得175条DNA条带,其中多态性条带为140条,占扩增总片段的80%,表明戴云山野生杨梅具有较高的遗传多样性水平;STRUCTURE聚类分析(基于模型)将41份野生杨梅划分为6个类群,结合Q值(Inferred ancestry of individuals)分析表明,戴云山脉野生杨梅存在丰富的遗传信息交流。展开更多
基金supported by the National Natural Science Foundation of China (30560007)
文摘The present study was conducted to assess the molecular characterization and genetic diversity amongst natural populations of Myrica rubra in Guangxi Zhuang Autonomous Region, China, thus to provide scientific evidence for germplasm conservation and exploitation. Using ISSR （inter-simple sequence repeats） markers, the level of genetic variation and the molecular characterization of 10 natural populations of M. rubra, originated from Guangxi Zhuang Autonomous Region in China, were performed. Based on 11 primers, 123 clear and reproducible DNA fragments were generated, of which 95 （77.24%） were polymorphic. The average value of Nei＇s gene diversity （He） was 0.268. The coefficient of genetic differentiation （Gst） was 0.341, revealing that 34.1% of the total molecular variance existed among populations. The Mantel statistical testing showed that the genetic distance was correlated to the geographic distance, but the correlation was not significant. Ten populations were divided into two big clusters according to unweighted pair group method with arithmetic mean （UPGMA） analysis. One consisted of populations of Rongxian （RX）, Hepu （HP）, Liangqing （LQ）, Marshan （MS）, Lingshan （LS） and Shansi （SS）, which originated from the southern Guangxi, while the other was composed of Guanyang （GY） and Lingui （LG） populations of northern Guangxi, Huanjiang （HJ） populations of northwestern Guangxi and Shanglin （SL） populations of southern Guangxi. The level of genetic variation in wild M. rubra population distributed in Guangxi is high. Gene drift within the population was responsible for genetic variation in wild M. rubra in Guangxi, and the effect of the genetic flow among inter-populations was not significant. Classification of wild M. rubra populations was correlated to climate and environment. The molecular characterization and diversity assessment of M. rubra is of immense value for planning conservation of its genetic resources and their exploitation for further studies.
文摘North China Mountain Walnut (NCMW) is one of the ancestors of extant cultivated species, and a valuable gene resource for resistance breeding of walnut in China. Inter-Simple Sequence Repeat (ISSR) primers were designed to evaluate the level and pattern of genetic diversity in eight populations of NCMW. Nine ISSR primers yielded 91 amplification products with different sizes, of which 84 (92.31%) were polymorphic. A high species-level genetic diversity was detected with Nei’s (H = 0.2592) and Shannon’s diversity (I = 0.4003). In contrast, the population-level genetic diversity was relatively lower (PPB = 43.27%, H = 0.1347, I = 0.1862). Coefficient of populations differentiation (GST) was 0.5066, indicating that inter-population and intra-population variation contributed 50.66% and 49.34% respectively to the total genetic variability. This relative level of variation was further supported by AMOVA analysis. Limited gene flow (Nm = 0.5133.), habitat fragmentation and geographical isolation might be responsible for the population structure of NCMW. UPGMA cluster analysis classified the eight populations into three groups which showed no significant relationship between the genetic similarity coefficient and geographic origin but showed remarkable association with morpho-physiological characters, particularly nut traits. The results of the study provide species-level and population-level genetic profiles for further exploitation and conservation of genetic diversity of NCMW.
文摘Morningglories (Ipomoea spp.) are among the most troublesome weedy species in agroecological environments. Ipomoea lacunosa is one of the most prevalent of these species. Localized adaptations resulted in the evolution of several I. lacunosa ecotypes in North America, which could potentially impact its response to crop management practices. To evaluate the genetic diversity and population structure of I. lacunosa populations, we amplified inter-simple sequence repeats loci by polymerase chain reaction (ISSR-PCR) of 64 accessions using 14 ISSR primers for Ipomoea. Of these, 64 polymorphic fragments were scored. Analysis of Nei’s genetic distance (GD) values placed the accessions into four genotypic clusters, two of which were composed primarily of accessions from Arkansas and Mississippi with GD between clusters of 0.318. The overall GD was 0.238, indicating a narrow genetic base. Population structure analysis determined three ancestral subgroups, with the majority of Arkansas and Mississippi accessions separated into two subgroups. The existence of various genotypes and ecotypes of I. lacunosa demonstrates the evolutionary diversification of this weedy species as it adapts to new colonized environments and agricultural activities.
基金supported by the National Key Basic High Technology Researchand Development Program of China (Grant No.2008CBA49B01)Knowledge Innovation Project of the Chinese Academy of Sciences (Grant Nos.KZCX2-YW-209 and KSCX2-YW-G-002)
文摘Ulva pertusa is a native species to Asia along the western coast of Pacific Ocean,with new occurrence records in the eastern coast of Pacific,the northwest coast of Atlantic and the Mediterranean Sea.However,little is known about its population genetic structure.In this study,twelve U.pertusa populations from 3 coastal areas of China:Qingdao,Yantai and Dalian,were applied to ISSR analysis.The selected 4 ISSR primers amplified 120 polymorphic bands totally.Nei's gene diversity (H) ranged from 0.0729 to 0.1496,and Shannon's information index (I) ranged from 0.1072 to 0.2196.Genetic diversity was greater within Qingdao populations (H=0.2069,I=0.3232).Analysis of molecular variance (AMOVA) showed the greatest variance within populations (68.57%),much less variance among populations (22.63%) and among areas (8.79%).Unweighted pair-group mean analysis (UPGMA) indicated that clustering of U.pertusa individuals mainly relates to their populations and geographic distances separating those populations.Genetic differentiation and limited gene flow among U.pertusa populations were indicated by ISSR analysis.
文摘采集戴云山脉自然群体的41份野生杨梅样品为材料,采用ISSR分子标记结合相关软件进行遗传结构分析。研究结果表明:筛选的13条引物共扩增获得175条DNA条带,其中多态性条带为140条,占扩增总片段的80%,表明戴云山野生杨梅具有较高的遗传多样性水平;STRUCTURE聚类分析(基于模型)将41份野生杨梅划分为6个类群,结合Q值(Inferred ancestry of individuals)分析表明,戴云山脉野生杨梅存在丰富的遗传信息交流。
