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1.
华山新麦草自然居群沿海拔梯度的遗传分化 总被引:10,自引:0,他引:10
华山新麦草为我国特有种 ,仅分布于陕西华山 ,是国家一级珍稀濒危植物和急需保护的农作物野生亲缘种。应用 RAPD技术 ,选取 8条引物对华山新麦草自然分布区的 3个山峪(种群 ) 1 1个样方 (亚居群 ) 79个华山新麦草个体的总 DNA进行随机扩增 ,共得到 65个RAPD位点。统计分析表明 ,在华山的 3个山峪 (居群 )中 ,黄埔峪 (居群 )与其它 2个山峪 (居群 )发生较显著的遗传分化 ;华山峪 6个亚居群的个体平均 RAPD位点数有随海拔的升高而下降的趋势 ;6个亚居群间的相似性系数也有随海拔的升高而下降的趋势 ;华山峪的高海拔亚居群和低海拔亚居群间表现出明显差异。主成分分析结果进一步证明了黄埔峪居群与华山峪居群和仙峪居群间、以及华山峪的高海拔亚居群与低海拔亚居群间已发生一定程度的分化。研究结果暗示海拔差异是导致华山新麦草自然居群遗传分化的主要因素 ,海拔差异造成的有限的基因流可能才是影响居群和亚居群遗传分化的主要因子 ,而亚居群内遗传变异程度则与该亚居群的所处的特定生境有关 相似文献
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华山新麦草自然居群的遗传结构和种内遗传多态性研究 总被引:11,自引:0,他引:11
华山新麦草为我国特有种,公分布在陕西华山,应用5种酶系统共13个基因位点对采自华山13个亚居群的华山新麦草进行等位酶分析,研究结果发现,多态性位点的比例(P)为69%,个位点等位基因的平均数(A)为1.8,平均每个位点的预期杂合性(He)为0.344,Simpson指数为0.998,证明华山新麦草居群内有较高的遗传多态性和克隆多样性,固定指数(F)显示有意义的负值(-0.252),预期的随机交配相比较,居群内有过多的杂合体,这可能与华山新麦草的交酸系统和繁育方式有关,平均的遗传距离为0.046(变化范围:0-0.139),大约有91%的遗传变异存在于亚居群内,应用间接法测得华山新麦草自然居群间的基因流(Nm)为2.77,明显你于一般风媒传粉植物(5.24),暗示华山新麦草自然居群的基因流水平似乎正处于一种临界状太,有进一步分化的潜能,但受多种因素的影响。 相似文献
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华山新麦草自然居群沿海拔梯度的的遗传分化 总被引:4,自引:0,他引:4
华山新麦草为我国特有种,仅分布于陕西华山,是国家一级珍稀濒危植物和急面保护有农作物野生亲缘种。应用RAPD技术,选取8条引物对华山新麦草自然分布分布区的3个山峪(种群)11个样方(亚居群)79个华山新麦草个体的总DNA进行随机扩增,共得到65个RAPD位点。统计分析表明,在华山的3个山峪(居群)中,黄埔峪(居群)与其它2个山峪(居群)发生较显著的遗传分化,华山峪6个亚居群的个体平均RAPD位点数有随海拔的升高而下降的趋势,6个亚居群间的相似性系数也有随海拔的升高而下降的趋势,华山峪的高海拔亚居群和低海拔亚居群间表现出明显差异。主成分分析结果进一步证明了黄埔峪居群与华山峪居群和仙峪居群间、以及华山峪的的高海拔亚居群与低海拔亚居群间已发生一定程度的分化。研究结果暗示海拔差异是导致华山新麦草自然居群遗传分化的主要因素,海拔差异造成的有限的基因流可能才是影响因居群和亚居群遗传分化的主要因子,而亚居群内遗传变异程度则与该亚居群的所处的特定生境有关。 相似文献
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华山新麦草胚和胚乳的发育研究 总被引:2,自引:2,他引:2
采用常规石蜡切片法,观察了华山新麦草胚和胚乳的发育过程,结果表明,华山新麦草胚和胚乳的发育过程与一般禾本科植物基本相同,胚胎发生属紫宛型,顶细胞和基都参与胚体的形成,胚胎发育经过二细胞原胚,多细胞原胚,球形原胚,梨形原胚,分化胚和成熟胚阶段,成熟胚具有胚根,胚芽,盾片,胚牙鞘,胚根鞘,外胚叶等典型禾本科植物成熟胚的结构,胚乳发育类型为核型,包括游离核阶段,细胞化阶段和生长成熟阶段,待大量游离核形成之后才形成细胞壁,紧贴胚囊的一层胚乳细胞最后形成种子的糊粉层,其余的胚乳细胞最后充满淀粉粒,其特点为:(1)有双球形原胚的现象;(2)反足细胞解体较早;(3)胚乳游离核时期和细胞时期胚乳细胞核的核仁多样。 相似文献
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华山新麦草大孢子发生始于孢原细胞。大孢子母细胞减数分裂形成直线型四分体。功能大孢子位于合点端,大孢子发育为蓼型胚囊。成熟胚囊为八核七细胞,卵细胞极性明显,助细胞在极核融合前已退化一个,另一个宿存,宿存助细胞丝状器明显,并保留退化助细胞的痕迹。极核排列方向不定,反足细胞在胚囊发育早期增殖,并液泡化。此外,在华山新麦草中发现有双孢原细胞及双胚囊的现象。 相似文献
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华山新麦草(Psathyrostachys huashanica keng)为我国特有种,仅分布在陕西华山。通过对自然种群传粉物候期观测发现,华山新麦草的传粉高峰期与海拔有一定关系。海拔每升高200m,传粉物候期就推迟2-3d;海拔差异超过500m的亚种群,传粉物候期就不会出现重叠。同时应用等位酶分析技术和E-统计分析间接估测华山新麦草自然种群的基因流(Nm),其值较一般风媒传粉植物低。通过华山新麦草资源状况、生长环境的调查以及移栽试验的观察,认为该物种稀的主要原因之一 可能是其生存竞争能力弱,最终被迫生长在其它物种所不能生存的环境。 相似文献
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岛屿植物舟山新木姜子居群遗传多样性的RAPD分析 总被引:7,自引:4,他引:7
基于随机扩增多态 DNA(RAPD)方法分析了舟山群岛濒危植物舟山新木姜子 (N eolitsea sericea) 6个居群的遗传多样性及分化程度。 10条随机引物扩增出 84个可分析位点 ,多态位点百分比 (PPL)为 3 8.10 %。经 POPOGENE分析发现 ,舟山新木姜子居群平均水平的多态位点百分比 (PPL )为 2 3 .18% ,Nei' s基因多样度 (HE)为 0 .0 793 ,Shannon信息指数 (H )为 0 .12 0 1,与其它岛屿植物比较具有中等偏低水平的遗传多样性 ;岛屿各居群间遗传分化程度较高 (Gst=0 .3 646) ;地理距离与遗传距离之间具有显著相关性 (r=0 .7697,P=96.62 % ) ,岛屿隔离效应是导致居群间遗传分化的重要因素。结合居群遗传多样性及UPGMA聚类分析 ,推测普陀山岛舟山新木姜子部分个体可能为大猫岛迁入的后裔 ,而朱家尖岛舟山新木姜子则由人为移植自普陀山岛。基于舟山新木姜子的物种保护及资源利用 ,建议加强现有自然居群的就地保护 ,促进居群自然更新 ;建立种质资源库 ,收集不同岛屿的种源进行混合繁殖 ,促进基因交流 ;选育优良品系用于海岛植被恢复及园林观赏 相似文献
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Psathyrostachys huashanica Keng is a perennial grass and belongs to genus Psathyrostachys under Triticeae.sathyrostachys is found in the center of Middle Asia and the Caucasus Mountain,while P.huashanica,a species endemic to China,is only located in Mt.Hua in the Shaanxi province,China.At present,the population of this species is decreasing,and reaching the edge of extinction.Due to the limitation in distribution and the importance as breeding material for germplasm storage,it has been considered as first class among the national protected rare plants.For this reason,the present study is significant in probing plant flora,origin and evolution of Triticeae,and crop breeding.Randomly amplified polymorphic DNA (RAPD)markers were used to analyze the genetic structure and differentiation of P.huashanica populations sampled in three valleys (Huangpu,Xian,and Huashan Valleys)in Mr.Hua.One hundred and twenty-two RAPDfragments were obtained in all 266 individuals with 20 primers with a mean of 6.1 (2-10)fragments per primer.The percentage of polymorphic loci (PPB)was 60.66%in Huangpu Valley,90.98%in Xian Valley,95.08%in Huashan Valley,and the total PPB was 95.08%,which indicated a highly genetic variability of P.huashanica.The Shannon's Information index and GST were 0.3306 and 0.3263,respectively,indicating that there were more genetic variations within the subpopulations than those among the subpopulations.The gene flow among the subpopulations of P.huashanica (Nm=1.0322)was much less than that of the common anemophytes (Nm=5.24).Mean genetic distance is 0.1571(range:0.0022-0.2901).The highest value of genetic distance was found between the subpopulation (hp1)of Huangpu Valley and the highest altitude subpopulation (h8)of Huashan Valley.Correlation analysis detected significant correlation between genetic distance and vertical distance of altitude.Clustering analysis and principal coordinate analysis revealed the genetic differentiation among the populations of P.huashanica.Differentiation mainly occurred between the higher altitude subpopulations and the lower altitude subpopulations,suggesting that altitude might be the major factor that restricted the gene flow between different altitude subpopulations and resulted in differentiation of subpopulations. 相似文献
12.
Psathyrostachys huashanica Keng is a perennial grass and belongs to genus Psathyrostachys under Triticeae. sathyrostachys is found in the center of Middle Asia and the Caucasus Mountain, while P. huashanica, a species endemic to China, is only located in Mt. Hua in the Shaanxi province, China. At present, the population of this
species is decreasing, and reaching the edge of extinction. Due to the limitation in distribution and the importance as breeding
material for germplasm storage, it has been considered as first class among the national protected rare plants. For this reason,
the present study is significant in probing plant flora, origin and evolution of Triticeae, and crop breeding. Randomly amplified
polymorphic DNA (RAPD) markers were used to analyze the genetic structure and differentiation of P. huashanica populations sampled in three valleys (Huangpu, Xian, and Huashan Valleys) in Mt. Hua. One hundred and twenty-two RAPD fragments
were obtained in all 266 individuals with 20 primers with a mean of 6.1 (2–10) fragments per primer. The percentage of polymorphic
loci (PPB) was 60.66% in Huangpu Valley, 90.98% in Xian Valley, 95.08% in Huashan Valley, and the total PPB was 95.08%, which indicated a highly genetic variability of P. huashanica. The Shannon’s Information index and G
ST were 0.3306 and 0.3263, respectively, indicating that there were more genetic variations within the subpopulations than those
among the subpopulations. The gene flow among the subpopulations of P. huashanica (Nm = 1.0322) was much less than that of the common anemophytes (Nm = 5.24). Mean genetic distance is 0.1 571 (range: 0.0022–0.2901). The highest value of genetic distance was found between
the subpopulation (hp1) of Huangpu Valley and the highest altitude subpopulation (h8) of Huashan Valley. Correlation analysis
detected significant correlation between genetic distance and vertical distance of altitude. Clustering analysis and principal
coordinate analysis revealed the genetic differentiation among the populations of P. huashanica. Differentiation mainly occurred between the higher altitude subpopulations and the lower altitude subpopulations, suggesting
that altitude might be the major factor that restricted the gene flow between different altitude subpopulations and resulted
in differentiation of subpopulations.
Translated from Acta Ecologica Sinica, 2005, 25(4): 719–726 [译自: 生态学报] 相似文献
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中华结缕草遗传分化的RAPD分析 总被引:4,自引:0,他引:4
中华结缕草 (ZoysiasinicaHance.)在我国是分布于东部沿海地区的一个受威胁禾草 ,形态上还有一个分布在海边的变种 ,长花中华结缕草 (Z .sinicavar.nipponicaOhwri)。采用 1 0条随机引物对采自我国不同地区 7个居群的 1 0 5个个体进行了RAPD扩增 ,对结果的AMOVA分析表明 ,中华结缕草组间遗传分化不显著 ,遗传变异只占总变异的 4.84% ,居群间遗传变异占总遗传变异的 2 4.71 % ,出现了显著的遗传分化 ,大部分变异存在于居群内部 ,占总变异的 70 .44%。不同数据处理方法得到了类似的结果 ,都支持哈迪 -温伯格平衡的假设。其中宁国汪溪居群和射阳海边居群变异最大 ,歙县新安江居群遗传变异最小。考虑到中华结缕草遗传结构和变异的这些特性 ,在取样策略、保护和育种方法上 ,都应该以群居为主 ,同时兼顾主要的异地居群 相似文献
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对华山新麦草(Psathyrostachys huashanica Keng ex P.C.Kuo)营养叶的净光合速率(Pn)和蒸腾速率(Tr)的日变化曲线进行了分析,并在对叶温(Tl)、气孔阻力(Rs)、光合有效辐射强度(PAR)和气温(Ta)的日变化曲线进行测定的基础上分析了它们对华山新麦草Pn的影响规律。结果表明:华山新麦草Pn的日变化曲线呈"三峰"型,峰值分别为6.5、6.2和9.0μmol.m-2.s-1,依次出现在9:30、11:30和16:30,而且具有明显的"午降"现象;Tr的日变化曲线呈"单峰"型,最大值为1.7 mmol.m-2.s-1,出现在13:30;Tl、Rs、PAR和Ta的日变化曲线均呈"单峰"型,峰值分别出现在12:30、11:30、12:30和13:30。华山新麦草的Pn对Tl、PAR和Ta的响应曲线均呈"抛物线"型,Pn在一定范围内与Tl、PAR和Ta呈正相关,随着Tl、PAR和Ta的升高逐渐增加至最大值后逐渐降低;而Pn与Rs则呈负相关,Pn在一定范围内随Rs的增大逐渐降低。根据拟合方程,华山新麦草营养叶的光补偿点和光饱和点分别为1.1和531.5μmol.m-2.s-1,说明该种类具有很强的喜光性,且对光照强度的适应范围较广。研究结果表明:较大的气孔阻力是造成华山新麦草叶片净光合速率偏低的主要原因。 相似文献
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Intergeneric crosses were made betweem Psathyrostachys huashanica
(2n=14, NN)and two Roegneria species, namely, R. ciliaris (2n=28, SSYY),
and R. tsukushiensis (2n=42, SSHHYY). Two combinations of P. huashanica
crossed with R. ciliaris and R. tsukushiensis produced adult hybrid plants. Although completely sterile, the hybrid plants developed rather vigorously, and were
morphologically intermediate between the two parents.Two spikelets per node in
part were observed in hybrids, which evidently came from P. huashanica. The
chromosome configurations of R. ciliaris × P. huashanica and R. tsukushiensis × P.
huashanica were 20.73 I+0.318 II, 24.80 I+1.578 II+0. 012 III, respectively.
Polypolar division was found at anaphase I in meiosis of two hybrids. Abnormal
meiosis in two hybrids was observed. The chromosome pairing indicates that there
is only a little chromosome homoeology between “N” genome of P. huashanicaand “S”, “Y” or “H” genomes of R. ciliaris and R. tsukushiensis. 相似文献
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目的:利用RAPD技术对9个家猪群体的遗传多样性进行分析,方法:采用RAPD技术对13/17罗伯逊易位纯合子猪易位杂合子猪及正常核型猪的三个群体,丹系长白猪群体,加系双肌臀杜洛克猪群体,加系双肌臀大约克猪群体,加系双肌臀长白猪群体及欧洲猪与易位杂合子猪产生的两个杂交后备猪群体的遗传多样性进行分析,并分别计算其共有带率F及遗传距离指数D,采用最小距离法绘制其树状聚类图。结果:19条引物的扩增结果产生多态性,共得到316条清晰稳定的多态型片段,片段长度在200-4000bp之间,由Nei的公式计算获得的遗传距离介于0.016-0.092之间,参照系统进化树可将9个品系划分为3个组群。结论:9个品系之间存在着明显的遗传差异,可作为进一步育种方案设计的依据。 相似文献