首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
三种耧斗菜属植物柱头的特征   总被引:7,自引:0,他引:7  
为了深入了解植物捕获花粉的机制和生殖策略,我们对3种耧斗菜属Aquilegia L.植物华北耧斗菜A. yabeana Kitagawa、无距耧斗菜A. ecalcarata Maxim.和秦岭耧斗菜A. incurvata P. K. Hsiao的雌蕊进行了扫描电镜和荧光显微镜观察,发现其柱头发育的特殊式样。其柱头位于花柱的腹缝面,由花柱腹缝两侧细胞发育成柱头乳突,在花期中从顶端朝花柱基部渐次成熟。伴随花柱向外弯曲,成熟的柱头表面相继呈现,逐渐增加了花粉落置的空间。这种柱头发育的式样通过延长柱头的可授期,增加了植物在不可预测的传粉环境下的繁殖机会。  相似文献   

2.
 利用9对SSR引物对中华猕猴桃(Actinidia chinensis)和美味猕猴桃(A. deliciosa)两近缘种的5个同域分布复合体和各自1个非同域分布居群进行了遗传多样性、居群遗传结构的分析以及种间杂交渐渗的探讨。结果表明:1)两物种共有等位基因比例高达81.13%,物种特有等位基因较少(中华猕猴桃:13.27%,美味猕猴桃:5.61%),但共享等位基因表型频率在两近缘种间存在差异,而且与各同域复合体中两物种样本的交错程度或间距存在关联;2)两种猕猴桃均具有极高遗传多样性,美味猕猴桃的遗传多样性(Ho=0 .749, PIC=0.818)都略高于中华猕猴桃(Ho=0.686,PIC=0.799);3)两猕 猴桃物种均具有较低的Nei’s居群遗传分化度,但AMOVA分析结果揭示种内异域居群间(FST=0.091 5)和同域复合体种间(FST=0.111 5)均存在一定程度的遗传分化;中华猕猴桃居群遗传分化(GST=0.086; FST=0.212 1)高于美味猕猴桃(GST= 0.080;FST=0.142 0);4)同域分布复合体两物种间的遗传分化(GST=0.020)低于物种内异域居群间的遗传分化(中华猕猴桃:GST=0.086; 美味猕猴桃:GST=0.080),同域复合体物种间的基因流(Nm=7.89 -29.75)远远高于 同种异域居群间(中华猕猴桃:Nm =2.663; 美味猕猴桃:Nm=2.880); 5)居群UPGMA聚类揭示在同一地域的居群优先聚类,个体聚类结果显示多数个体聚在各自居群组内,但各地理居群并不按地理距离的远近聚类,这与Mantel相关性检测所揭示的居群间遗传距离与地理距离没有显著性相关的结果一致。进一步分析表明两种猕猴桃的遗传多样性和居群遗传结构不仅受其广域分布、远交、晚期分化等生活史特性的影响,同时还与猕猴桃的染色体基数高 (x=29)、倍性复杂和种间杂交等因素密切相关,其中两种猕猴桃的共享祖先多态性和同域分布种间杂交基因渗透对两猕猴桃的居群遗传结构产生了重要影响。  相似文献   

3.
运用ISSR分子标记技术,通过制定挖掘采样、"+"形采样及"垂直"采样3种采样方案,对贺兰山丁香(Syringa pinnatifolia var.alanshanica)不同居群的克隆多样性、克隆生长格局及其遗传多样性进行了分析.克隆多样性分析表明:挖掘采样方式采到的3个克隆系内,各自所包含的单株间具有完全相同的基因型;"垂直"采样及"+"形采样的7个居群、 239个样品表现出136个不同的基因型或克隆,显示贺兰山丁香具有较高的克隆多样性(D=0.994)及基因型分布均匀性(E=0.985).克隆生长空间格局分析表明,贺兰山丁香为密集型克隆植物.每个居群都由多克隆组成,克隆生长只发生在同一丛内,多数基株只含有1个分株,最多可达8个.物种水平上的平均克隆大小(NC)和平均基因型比例(PD)分别为1.757和0.569.对贺兰山丁香遗传多样性分析的结果显示,在居群水平和物种水平上都保持着较高的遗传多样性,其遗传变异主要存在于居群内;但居群间分化程度较低(GST=0.320),表明自然居群间基因交流有限.  相似文献   

4.
Zhao QF  Wang G  Li QX  Ma SR  Cui Y  Grillo M 《Hereditas》2006,143(2006):33-40
Plants of the genus Kobresia are alpine grass species of high ecological and economic importance. Vegetative growth is the dominant means of reproduction for the Kobresia. Studies suggest that substantial vegetative growth can reduce genetic diversity and renders populations less able to buffer changing and extreme conditions. Kobresia are dominant species in the Qinghai-Tibet plateau in China where they face harsh conditions and frequent disturbance. The genetic diversity of five Kobresia species (K. humilis, K. royleana, K. kansuensis , K. tibetica and K. setchwanensis) from the Qinghai-Tibet plateau was assessed. The results reveal high genetic diversity at the population level for all of the species and there does not appear to be a relationship between altitude and genetic diversity. AMOVA analysis shows that most genetic variability resides among individuals within populations, whereas only a minor portion is found among populations. Of the five species, K. royleana and K. kansuensis have the highest levels of gene flow and the lowest genetic differentiation. While K. setchwanensis has the lowest gene flow and the greatest genetic differentiation. The level of gene flow between populations and the mating system play a critical role in the genetic structure of these Kobresia populations. Despite the predominance of vegetative growth enough sexual reproduction occurs to maintain the relatively high genetic diversity in Kobresia populations.  相似文献   

5.
景东报春(Primula interjacens Chen)是一分布在中国云南中南部的稀有的、分布区狭窄的特有种.该种含2个变种:原变种景东报春(P.interjacens Chen var.interjacens),现存一个居群;和光叶景东报春(P.interjacens Chen var.epilosa C.M.Hu),有2个居群.本文用ISSR分子标记对景东报春现存的3个居群进行了遗传多样性分析.和我们最初的预计相反,尽管居群小、分布区狭窄,景东报春的遗传多样性却很高(在居群水平的多态位点率P=59.75%,基因多样性HE=0.236 8,Hpop=0.345 9;在种的水平的多态位点率P=75.47%,遗传多样性HT=0.320 5,总的遗传多样性Hsp=0.4618).推测异型花和杂交可能是维持高的遗传多样性的原因.Nei的遗传多样性水平(26.13%)和Shannon多样性指数(25.09%)显示居群间存在中度分化.尽管景东报春原变种和变种在形态上有区别,但用非加权配对算数平均法(UPGMA)聚类分析的结果表明,两者并没有明显的遗传分化,可处理为一个单一的分类单元.基于观察到的居群遗传信息,建议采取就地保护和迁地保护的保护措施.  相似文献   

6.
The endemic Hawaiian genus Brighamia (Campanulaceae) comprises two federally endangered, morphologically similar species, B. insignis from Kaua`i and Ni`ihau and B. rockii from Moloka`i. To assist the design of conservation management programs for these taxa, isozyme analyses were performed to assess the levels of genetic diversity at the population and species levels, including comparisons within and among seven natural populations and one ex situ collection each of B. insignis and B. rockii. Our sampling (N = 80) represents ~41% of all known individuals in the wild. Isozyme analyses revealed levels of genetic variation comparable to those reported for other Hawaiian flowering plant taxa but low levels of genetic variation at the population and species levels when compared to flowering plants in general. Ex situ individuals (N = 61) were genetically representative of natural populations and hence may appropriately serve as stock for population augmentations. The two morphologically similar Brighamia species were highly distinct genetically. The combination of morphological and ecological similarity with allozymic dissimilarity observed in Brighamia is unique among the Hawaiian taxa studied to date.  相似文献   

7.
利用ISSR分子标记方法对分布在浙江省境内的7个短柄枹种群的遗传多样性和遗传分化进行了分析。从100个引物中筛选出12个用于正式扩增的ISSR引物,在7个种群140个个体中共检测到132个位点,其中多态位点118个,多态位点百分率(P)为89.39%,各种群P平均为58.87%。短柄枹总的Shannon信息指数(I)为0.493 3、Nei指数(h)为0.334 7,各种群I平均为0.336 2、h平均为0.229 1。PIh均显示云峰种群最高,天台山种群最低。AMOVA分子差异分析表明,67.97%的变异存在于种群内,32.03%的变异存在于种群间,种群间的基因分化系数(GST)为0.315 4。短柄枹种群间的基因流为(Nm)为1.085 3。7个种群的平均遗传距离为0.173 9。利用UPGMA法对7个种群进行聚类,结果显示天台山和雪窦山种群聚成一类,其它5个种群聚成另一类。  相似文献   

8.
Aquilegia buergeriana var. oxysepala is a vulnerable herb, for which 20 microsatellite markers were developed. The applicability of these markers was confirmed by genotyping of 66 individuals collected from four natural populations in Japan. Of the 20 loci, 15 showed polymorphism. For the 15 polymorphic markers, the number of alleles per locus ranged from 2 to 12, and the expected and observed heterozygosities ranged from 0.13 to 0.77 and 0.02 to 0.65, respectively. The markers described here are sufficiently polymorphic and informative to investigate the genetic diversity and population genetic structure of A. buergeriana var. oxysepala.  相似文献   

9.
The acquisition of floral nectar spurs is correlated with increased species diversity across multiple clades. We tested whether variation in nectar spurs influences reproductive isolation and, thus, can potentially promote species diversity using two species of Aquilegia, Aquilegia formosa and Aquilegia pubescens, which form narrow hybrid zones. Floral visitors strongly discriminated between the two species both in natural populations and at mixed-species arrays of individual flowers. Bees and hummingbirds visited flowers of A. formosa at a much greater rate than flowers of A. pubescens. Hawkmoths, however, nearly exclusively visited flowers of A. pubescens. We found that altering the orientation of A. pubescens flowers from upright to pendent, like the flowers of A. formosa, reduced hawkmoth visitation by an order of magnitude. In contrast, shortening the length of the nectar spurs of A. pubescens flowers to a length similar to A. formosa flowers did not affect hawkmoth visitation. However, pollen removal was significantly reduced in flowers with shortened nectar spurs. These data indicate that floral traits promote floral isolation between these species and that specific floral traits affect floral isolation via ethological isolation while others affect floral isolation via mechanical isolation.  相似文献   

10.
云南松及其近缘种的遗传变异与亲缘关系   总被引:4,自引:0,他引:4  
The authors investigated the genetic diversity of 29 natural populations representing Pinus yunnanensis Franch. and its two close relatives, P. densata Mast. and P. kesiya Royle ex Gordn. var. langbianensis (A Chey.) Gaussen. Horizontal starch gel electrophoresis was performed for macrogametophytes collected from populations in Yunnan, Sichuan and Guangxi. Allozyme data for 33 loci of 14 enzymes demonstrated high levels of genetic variation at both population and species levels in comparison with other conifers, with the mean values for populations being P=0.694, A=2.0 and He=0.145 for P. yunnanensis; P=0.714, A=2.0 and He=0.174 for P. densata; and P=0.758, A=2.1 and He=0.184 for P. kesiya var. langbianensis. Based on Wright's F-statistics, the fixation index of P. yunnanensis, P. densata and P. kesiya var.langbianensis were 0.101, 0.054 and 0.143, respectively, indicating that the populations were largely under random mating. Based on Nei's genetic distance, the genetic differentiation was not obvious among the three species (i.e. the genetic distance was less than 0.075). Because of the wider distribution of P. yunnanensis with greater variety of habitats, it was shown that the genetic differentiation among the P. yunnanensis populations was larger than that of the populations of the other two species. According to morphological, geographic and allozymic evidences, the authors suggested that the three species be better treated as varieties under a single species. In addition, the extensive gene flow among the three pine species resulted in great genetic diversity and evolutionary potential. Also, high level of genetic variation of P. yunnanensis provides important basis for its genetic improvement and breeding in future.  相似文献   

11.
水杉栽培居群的遗传多样性研究   总被引:1,自引:0,他引:1  
利用RAPD技术,对9个水杉(Metasequoiaglyptostroboides)栽培居群的遗传多样性进行了初步研究。用10bp的随机引物16条,共扩增出103个位点,其中37个为多态位点,占35.92%。各居群的多态位点百分率在16.50%~33.01%之间。POPGENEversion1.31软件处理结果如下:居群的Shannon’s信息指数为0.1930。遗传距离在0.0130~0.0650之间,遗传一致度在0.9370~0.9871之间。AMOVA分析结果显示遗传变异主要存在于居群内,占89.05%,居群之间有一定的分化。上述结果表明水杉栽培居群的遗传多样性略低于自然居群,涵盖了自然居群近80%的遗传多样性。由此可以确认栽培水杉的种源是经过混合的,它们在相当程度上代表了自然居群的遗传多样性水平。采自潜江的9株丛枝水杉(Metasequoiaglyptostroboidesvar.caespitosa)没有扩增出特有位点,将其视为一个居群根据遗传一致度作UPGMA聚类分析时,该居群和湖北的3个居群及南京(NJ)、成都(CD)居群聚在一起;单株聚类时丛枝水杉也没有聚成独立的一支,而是比较分散,因此不支持将丛枝水杉作为水杉的一个变种的分类处理。从亲缘关系上看,丛枝水杉应当归属于湖北潜江蚌湖种子园(BH)和湖北潜江广华(GH)居群,这与其分布现状也是吻合的。  相似文献   

12.
多叶重楼遗传多样性的ISSR分析   总被引:1,自引:0,他引:1  
采用ISSR分子标记对多叶重楼种下3个变种的8个居群共208份样品的遗传多样性进行了分析。l4条引物共检测到251个清晰的扩增位点,其中多态位点235个。在物种水平上,多态位点百分率(PPB)达93.63%,Nei′s基因多样性指数(HE)为0.2204、Shannon′s信息指数(HO)为0.3532。在居群水平上,多态位点百分率(PPB)为50.45%,Nei′s基因多样性指数(HE)为0.1405,Shannon′s信息指数(HO)为0.2194,这些均表明多叶重楼的遗传多样性水平较高。此外,还用NTSYS软件对样品进行了UPGMA聚类分析,结果显示滇重楼的6个居群聚为一支,滇重楼与狭叶重楼有较近的亲缘关系,而与长药隔重楼之间的遗传分化较大。本研究提出了合理保护重楼植物资源的若干措施,为进一步开展滇重楼优质种质引种驯化,实现种质资源多样性的合理保护和可持续利用提供参考。  相似文献   

13.
Ten different oligonucleotide primers of arbitrary sequence were used in Capillary and Air Thermocycler to amplify genomic total DNA of Paeonia suffruticosa subsp. spontanea and P. rockii isolated from several local populations in Shanxi, Shaanxi and Gansu provinces. Under the strictly standardized amplification condition for all the primers, these primers yielded clear and reproducible bands corresponding to amplified products and separable by agarose gel electrophoresis. Among a total of 71 bands amplified, 16(22. 5%) were polymorphic in a single individual of P. suffruticosa subsp. spontanea, while among a total of 76 bands 21(27.6%)were polymophic in a single individual of P. rockii. On an average,the pairwise marker difference between band profiles of conspecific individuals (different populations) was 7.9 for P. suffruticosa subsp. spontanea and 8.7 for P. rockii respectively. The average marker difference between P. suffruticosa subsp. spontanea and P. rockii was 10.3. Obviously, greater number of plants and primers will be required to detect satisfactorily level of genetic diversity. These preliminary results showed that intraspecific genetic diversity was low for the two endangered species. RAPD as a molecular marker was useful and feasible for detecting the genetic variation within species of wild moutans. And it was also potential for studying evolution and relationships between species.  相似文献   

14.
Geographic differences in floral traits may reflect geographic differences in effective pollinator assemblages. Independent local adaptation to pollinator assemblages in multiple regions would be expected to cause parallel floral trait evolution, although sufficient evidence for this is still lacking. Knowing the intraspecific evolutionary history of floral traits will reveal events that occur in the early stages of trait diversification. In this study, we investigated the relationship between flower spur length and pollinator size in 16 populations of Aquilegia buergeriana var. buergeriana distributed in four mountain regions in the Japanese Alps. We also examined the genetic relationship between yellow‐ and red‐flowered individuals, to see if color differences caused genetic differentiation by pollinator isolation. Genetic relationships among 16 populations were analyzed based on genome‐wide single‐nucleotide polymorphisms. Even among populations within the same mountain region, pollinator size varied widely, and the average spur length of A. buergeriana var. buergeriana in each population was strongly related to the average visitor size of that population. Genetic relatedness between populations was not related to the similarity of spur length between populations; rather, it was related to the geographic proximity of populations in each mountain region. Our results indicate that spur length in each population evolved independently of the population genetic structure but in parallel in response to local flower visitor size in different mountain regions. Further, yellow‐ and red‐flowered individuals of A. buergeriana var. buergeriana were not genetically differentiated. Unlike other Aquilegia species in Europe and America visited by hummingbirds and hawkmoths, the Japanese Aquilegia species is consistently visited by bumblebees. As a result, genetic isolation by flower color may not have occurred.  相似文献   

15.
同域分布的近缘物种常常发生杂交而导致种间基因渐渗, 从而对相关物种的自然居群遗传结构产生重要影响, 近缘种间的杂交渐渗已成为进化生物学和保护生物学关注的热点。本研究采用8对cpSSR引物对我国西部高原台地向中东部丘陵平原过渡地带同域重叠分布的猕猴桃属(Actinidia)7个物种的自然居群遗传多样性、居群遗传结构和同域分布种间遗传分化进行了检测。结果表明: (1)在6个多态性位点检测到18个等位基因形成的42个单倍型, 尽管各单倍型间显示了复杂的网状进化关系, 但还是具有明显的物种特异性; (2)各物种有丰富的cpSSR遗传多样性, 但种间存在较大差异, 绵毛猕猴桃(Actinidia fulvicoma var. lanata)的遗传多样性水平最高(P = 62.50%, hT = 0.173, HT = 0.897), 美味猕猴桃(A. deliciosa)的最低(P = 37.5%, hT = 0.041, HT = 0.516); (3)尽管不同物种的居群分化程度存在较大差异, 但种内居群间存在明显分化(GST为0.319–0.780, FST为0.401–0.695), 居群间的基因流不足(Nm为0.219–0.747<1); 其中以美味猕猴桃的居群遗传分化度最高(GST = 0.780, FST = 0.695); (4)遗传分化系数GST(unordered alleles)与NST(ordered alleles)无显著差异, 揭示本研究的大多数猕猴桃属物种不存在系统地理结构, 与用Mantel检验得出的居群遗传距离和地理距离不存在显著性相关的结果一致; (5)除了中华/美味猕猴桃复合体(A. chinensis / A. deliciosa complex)的湖北五峰(HW)和广西资源(GZ)两个同域复合居群外, 同域分布的物种间遗传分化强烈(FST为0.476–0.990), 与UPGMA聚类时多数居群按各自物种聚类的结果一致。进一步分析表明, 中华/美味猕猴桃复合体近缘种间存在明显的共祖多态性和杂交渐渗现象, 近缘种植株分布的交错程度以及是否存在亚居群结构对杂交渐渗存在着重要影响。亲缘关系较远的物种间杂交渐渗事件稀少, 但存在个别同塑事件。本研究结果有助于进一步了解猕猴桃属植物自然居群cpDNA的遗传特性和渐渗杂交进化模式, 为我国猕猴桃野生种质资源保育及可持续开发利用提供基础数据和科学依据。  相似文献   

16.
矮牡丹与紫斑牡丹RAPD分析初报   总被引:55,自引:0,他引:55  
用10个任意序列的寡核苷酸片段作为引物,将采自陕西、山西、甘肃等地矮牡丹与紫斑牡丹基因组DNA,在毛细管气浴式PCR热循环仪上随机扩增。在对所有引物扩增条件严格标准化的条件下,这些引物可产生清楚的、可重复的与扩增产物相应的琼脂糖凝胶电泳区带。这10个有效扩增的引物在矮牡丹平均每一个体中扩增出71条带,其中多态的带16条(22.5%),在紫斑牡丹平均每一个体中扩增出76条带,其中多态的带2l条(27.6%)。对每两个个体,每条多态带进行成对比较,累加后求分子标记差异的平均值。在矮牡丹3个居群间的平均差异是7.9,在紫斑牡丹4个居群间的平均差异是8.7,在矮牡丹与紫斑牡丹2个种间的平均差异是10.3。显然,若用来扩增的植物个体数目和引物数目增加,将会得到更满意的结果。初步结果表明濒危植物矮牡丹与紫斑牡丹种内低水平的DNA多态性。RAPD技术用于检测野生牡丹居群内与居群间的遗传变异是有用的与可行的;用于研究种间的进化和亲缘关系也有潜力。  相似文献   

17.
利用5个DNA片段及12个微卫星标记(SSR)对姜状三七(Panax zingiberensis C.Y.Wu et K.W.Feng)的遗传多样性和遗传分化进行分析。结果显示,与其他人参属(Panax)植物相比:姜状三七具有相对较高物种水平的核苷酸多态性和等位基因数;在居群水平上,景谷居群具有最高的核苷酸多态性和等位基因数,而江城居群最低。AMOVA分析结果表明,姜状三七在物种水平上具有一定程度的遗传分化,但不显著;在居群水平,江城居群与其他居群间的分化程度最高,其他居群间遗传分化不明显。Structure分析结果也显示江城居群与其他居群被聚类到不同分组,且形态特征相近的样本并未聚到一起,同一分布点的样本遗传成分更相似。  相似文献   

18.
紫斑牡丹遗传多样性的ISSR分析   总被引:1,自引:0,他引:1  
利用ISSR标记对一个居群内的16个紫斑牡丹品种材料进行基因组多态性分析,从100条引物中筛选出15条用于紫斑牡丹的ISSR扩增。共扩增出134条带,其中多态性条带96条,多态性百分率为71.6%。根据ISSR扩增结果,利用NTSYSpc 2.10e软件进行Jaccard相似性系数分析,16个紫斑牡丹品种的遗传相似系数为0.45~0.93。UPGMA聚类分析结果显示,在遗传相似系数0.534处,16个紫斑牡丹品种材料可分为4类。第Ⅰ类中的6个紫斑牡丹品种材料中有5个为皇冠型品种,1个单瓣型,其他类中也有皇冠花型品种但未聚在Ⅰ类中;第Ⅱ类仅有1个‘粉盘托桂’,它是所选材料中唯一的托桂型品种,单独聚为一类;第Ⅲ类由不同花色、花型品种聚为一类,可见亲缘关系较近的紫斑牡丹品种性状变异性也很大;第Ⅳ类中A组品种材料均为白色,花型有单瓣型、荷花型和绣球型;B组仅有一个‘银线女’,它是所选材料中唯一的红色绣球型材料。研究表明,不同相似系数的遗传聚类划分与花色、花型之间并非完全具有相关性。  相似文献   

19.
根据 2 2个等位酶位点遗传变异 ,探讨了韩国境内委陵菜 (PotentillafragarioidesL .var.sprengeliana)的遗传多样性和种群结构。酶位点的多态位点百分比为 5 9 1%。种和种群水平上的遗传多样性比较高 ,分别为Hes=0 .2 10 ,Hep=0 .199;而种群的分化水平则相对较低 (GST=0 .0 74)。 19个种群中随机交配的偏差为FIS=0 .331。每代迁移数的间接估计 (Nm=3.15 )表明该种在韩国的种群间基因流较高。另外 ,固定指数分析显示在一些种群和位点有轻微的杂合子缺乏。种群间平均遗传一致度为 0 985。这些韩国委陵菜种群存在于较为均一的生境 ,这很有可能是造成其种群遗传一致性较高的原因。  相似文献   

20.
Knowledge of population size is an important step for identifying populations of immediate conservation concern. However, this task is difficult in plant species that exhibit clonal growth, since a simple “head count” may not be appropriate. Here, I determine the genetic population size and the extent of clonality in the four known populations of a rare sunflower, Helianthus verticillatus. Previous work in this species revealed high genetic diversity in all populations but significant fitness differences among them. In this study, populations exhibited high clonal diversity but consisted of far fewer genetic individuals than previously reported. Moreover, the clonal structure of populations was clumped, such that genotypes were highly clustered, which may promote selfing among genets. The results of this study are related to previously examined levels of genetic diversity and fitness, and findings are discussed in the context of the ecological and biological dynamics in clonal plant populations. Finally, the results of this study led to an upgrade in the priority status of this species for the Endangered Species List.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号