拟环纹豹蛛不同地理种群遗传多样性的AFLP标记研究

为查明拟环纹豹蛛Pardosa pseudoannulata不同地理种群的遗传多样性机制,应用AFLP技术对6个拟环纹豹蛛地理种群的遗传多样性进行了研究分析。8对引物组合扩增出1 038个AFLP条带,其中多态性条带占86.622%,全部个体显示了各自独特的AFLP图谱。AFLP标记的遗传多样性分析结果表明： 拟环纹豹蛛无论在物种水平(P=86.62%,H=0.2622,I=0.3101),还是在种群水平（P=73.0%,H=0.2155,I=0.2554）都表现出较高的遗传多样性。其中湖南长沙雷锋镇种群内遗传变异最大,云南高黎贡山福贡种群内遗传变异最小,华南北部（湖南、湖北、江西）地区拟环纹豹蛛遗传多样性明显高于华南南部（云南、海南）种群。据种群变异来源分析,有35.77%的遗传变异来自种群间,64.23%的变异来源于种群内（N_m=0.898）,不同地理种群显示出一定的遗传分化。分析认为海拔是影响拟环纹豹蛛遗传分化的重要因素,这为进一步明确我国稻田狼蛛优势种群在农药胁迫下的遗传适应性机制提供了实验依据。     

应用单克隆抗体评价拟环纹豹蛛对褐飞虱的控制作用

应用褐飞虱的单克隆抗体 4 B8研究了 1999年浙江大学华家池校区农场汕优 6 3单季晚稻田中拟环纹豹蛛对褐飞虱的捕食作用。采用盘拍法的调查结果表明 ,褐飞虱、拟环纹豹蛛种群数量高峰期均在水稻生长后期 (9月中旬 ) ,最大种群密度分别为12 6头 /丛和 1.83头 /丛。对每次捕获的每头拟环纹豹蛛样品的抗体夹心 EL ISA检测结果表明 ,拟环纹豹蛛对褐飞虱单克隆抗体的阳性反应率与田间褐飞虱的生物量及拟环纹豹蛛对褐飞虱的占有量显著相关。定量评估结果表明 ,在此密度条件下 ,拟环纹豹蛛对褐飞虱的最大捕食率仅为 2 .2 8%。拟环纹豹蛛对褐飞虱的平均捕食量、总捕食量和捕食率与田间褐飞虱的生物量显著相关。总捕食量、捕食率与拟环纹豹蛛种群密度极显著相关     

拟环纹豹蛛的视觉距离和颜色选择

为了探明拟环纹豹蛛（Pardosa pseudoannulata）的视觉距离与环境颜色选择情况,通过采用死果蝇(Drosophila melanogaster)和拟环纹豹蛛为试验材料,自制试验设备,分别测定了拟环纹豹蛛的视觉距离（3 cm、4 cm、5 cm、6 cm、7 cm）和其对红、橙、黄、绿颜色的选择。第一组试验中,在拟环纹豹蛛饥饿的情况下,观察记录其对不同距离下果蝇的选择停留时间,以此来确定它们的视觉距离。第二组试验中,观察记录拟环纹豹蛛对不同颜色的选择停留时间,以此来确定它们的环境颜色选择情况。第一组试验结果表明,拟环纹豹蛛在视觉上可以感知距离,它们的视觉对于3cm,4cm,5cm,6cm这4个距离的果蝇都具有敏感性。拟环纹豹蛛对距离3 cm和距离4 cm的果蝇的视觉敏感性相近且最好,对距离5 cm和距离6 cm的果蝇仍具有视觉敏感性,且敏感性相近,但对距离5cm比距离4cm的果蝇的偏爱选择指数明显下降（P<0.05）,说明敏感性显著下降,对距离7 cm以上果蝇的视觉感知几乎不存在。通过拟环纹豹蛛选择停留在有果蝇处的标准曲线y=-9.6770x 118.74,R2=0.8378和选择停留在无果蝇处的标准曲线y=9.6750x-18.729,R2=0.8377,可知随着果蝇距离的增加,拟环纹豹蛛视觉的感知性逐渐减弱,甚至消失,说明果蝇的距离与拟环纹豹蛛视觉的敏感性呈负相关的关系。第二组拟环纹豹蛛对颜色选择的试验中,通过计算出拟环纹豹蛛对4种颜色的偏爱选择指数,即红色为35.40%±1.60%,绿色36.03%±1.60%,黄色18.01%±1.60%,橙色10.56%±1.60%,得出拟环纹豹蛛对黄色和橙色的敏感性显著低于对红色和绿色的敏感性（P<0.05）,它们对红色和绿色最敏感,说明拟环纹豹蛛对不同波长的光色敏感性存在差异。     

听觉对拟环纹豹蛛(Pardosa pseudoannulata)定位猎物的影响

为探明蜘蛛的听觉感受器在寻觅定位猎物中的作用,在实验室内比较拟环纹豹蛛(Pardosa pseudoannulata)对有果蝇振翅声源端和无声源端的反应。结果表明:近距离内,拟环纹豹蛛对有声源端选择指数显著高于无声源端,但距离增大至15 cm后,拟环纹豹蛛选择指数无显著差异;拟环纹豹蛛停留时间也呈类似变化,距离12 cm内,拟环纹豹蛛在有声源端停留时间较长,多于总观察时间的1/2,且拟环纹豹蛛在有声源端停留时间显著高于无声源端,距离增加后,拟环纹豹蛛对声音敏感程度下降,停留时间无显著差异;总之,离声源距离越近,拟环纹豹蛛对声音的敏感性越高,随着距离增加,敏感性逐渐降低,声源间距与拟环纹豹蛛成功定位猎物有明显负相关性,拟环纹豹蛛在一定距离下可以依靠听觉定位猎物;另外,拟环纹豹蛛性别对听觉感受器的敏感度有一定影响,雌性拟环纹豹蛛对果蝇振翅声音更为敏感,选择指数更高。     

不同干扰生境下河口莲座蕨遗传多样性分析

该研究利用 ISSR 分子标记,对不同生境下的6个河口莲座蕨种群进行遗传多样性分析。结果表明：从44条ISSR引物中筛选出8条能够扩增出清晰、稳定条带的引物,对6个河口莲座蕨种群进行基因组 DNA扩增,共扩增出144条带,其中多态性条带119个,多态性条带比率为93.7％,Nei’s遗传多样性指数(H)为0.296,Shannon多样性指数(I)为0.457,遗传分化指数(Gst)为0.1520,种群遗传一致度和遗传距离分别为0.9138~0.9548和0.0584~0.0901;UPGMA聚类分析表明,种群间遗传距离与空间距离和生境类型有关。河口莲座蕨在不同干扰程度的生境中,种群具有高水平的遗传多样性,一定强度或频率的干扰生境中,种群遗传多样性较高,与海拔、坡度和坡向无相关性。     

内蒙古典型草原羊草种群遗传分化的RAPD分析

运用 RAPD技术对内蒙古典型草原不同生境 8个羊草种群进行分析。采用 2 4个随机引物 (10 nt)在 8个种群中共检测到2 2 4个扩增片断 ,其中多态性片断 173个 ,总的多态位点百分率达 77.2 % ,特异性片断 2 2个 ,占 9.82 % ,平均每个引物扩增的DNA带数为 9.3 3条。利用 Nei指数和 Shannon指数估算了 8个种群的遗传多样性 ,并计算种群相似系数和遗传距离 ,运用UPGMA法进行聚类分析。结果表明 :羊草大部分的遗传变异存在于种群内 ,只有少部分的遗传变异存在于种群间 ,Nei指数和Shannon指数计算结果分别为 85.4%和 66.8% ;羊草不同种群的遗传多样性存在差异 ;8个羊草种群平均遗传距离为 0 .2 3 16,变异范围为 0 .1587～ 0 .2 70 0 ,说明 8个羊草种群间的遗传变异不大 ,即 :在较小地理范围内羊草的遗传分化程度较小 ;8个种群可聚为 3个类群 ,聚类结果显示生境相似的种群能够聚在一起 ,而地理距离最近的种群不一定归为一类 ,说明小范围内羊草种群间的遗传分化与地理距离不存在相关性 ,而与其生境间的相似度相关。影响遗传相似性的不是单一因子而是各种因子的综合作用 ,较小地理范围内羊草种群间的遗传分化主要是由环境的异质性所引起的     

四种杀虫剂对拟环纹豹蛛(Pardosa pseudoannulata)肠黏膜通透性的影响

采用异硫氰酸荧光素-葡聚糖(FITC-D)作为示踪物质,通过检测拟环纹豹蛛(Pardosa pseudoannulata)血液内的荧光素浓度,研究了两种生物源杀虫剂和两种化学源杀虫剂对拟环纹豹蛛肠黏膜通透性的影响.结果表明:4种杀虫剂处理后拟环纹豹蛛血液中的荧光素浓度远高于对照组,各个处理组拟环纹豹蛛血液样本中的荧光素浓度均与对照组存在极显著差异,可见4种杀虫剂均将对拟环纹豹蛛肠黏膜的屏障功能造成损伤,导致大分子物质易于通过;其中1.5%除虫菊素水乳剂三保奇花和Bt制剂强杀处理后拟环纹豹蛛中肠黏膜的通透性高于仿烟碱类化学杀虫剂吡虫啉处理组,差异达到显著水平,但与有机磷杀虫剂敌百虫处理组差异不显著.拟环纹豹蛛的肠黏膜组织亦具有一定的抗逆能力,接受单次杀虫剂处理后,存活的拟环纹豹蛛其肠黏膜的屏障功能约在6～10d内可以恢复.     

农田蜘蛛群落结构及其多样性研究

本文对南宁地区农田自然蜘蛛群落和旱地狼蛛亚群落结构及其多样性进行了研究。 1.农田区蜘蛛群落有14科、41属、80种。主要成分是食虫瘤胸蛛、拟环纹狼蛛、拟水狼蛛、奇异獾蛛和豹蛛属种类,个体数以食虫瘤胸蛛最多。旱地狼蛛亚群落主要成分是奇异獾蛛和豹蛛属种类。 2.稻田区蜘蛛群落多样性指数以田埂杂草群落最高,早稻田群落最低。多样性、均匀度和种类丰富度时间格局是早、晚稻皆随时间序列增加。平均多样性、均匀度和个体数,晚稻均高于早稻。狼蛛更群落多样性和均匀度以草地最高。 3.应用群落比例相似性和聚类分析表明,拟环纹狼蛛与拟水狼蛛和奇异獾蛛与豹蛛属种类是组成当地农田区的水田和旱地生境具有代表性的两个狼蛛亚群落主要成分。 本文试图揭示农田生态系统中的稻田蜘蛛,在不受化学农药干扰下群落结构及其多样性变化,并以狼蛛亚群落为代表,比较农田区内不同生境的群落结构及多样性与生境生态特征的关系,为害虫防治和动物资源的利用提供参考。     

星豹蛛不同地理种群COⅠ基因序列差异初步分析

星豹蛛广泛分布于我国南北各省的农田、果园、菜田及森林等生态系统中,是农林害虫的重要天敌。本文测定了采自山西临汾、运城、晋中和忻州4个地区的星豹蛛地理种群细胞色素氧化酶亚基Ⅰ(COⅠ)基因部分序列(932bp),并对此序列及从NCBI网站GenBank上下载的采自国内10个省市星豹蛛相应序列一并进行遗传多样性研究,分析了碱基组成和变异情况以及核苷酸序列差异,采用距离矩阵邻接法和最大简约法构建了不同的分子系统树,得到了相似的拓扑结构,从分子水平初步探讨了星豹蛛不同地理种群的遗传结构。结果表明,星豹蛛地理种群间的COⅠ序列同源性达98%～100%,显示出较大的遗传差异。序列比对后从供试14个COⅠ序列中共检测出41个变异位点和6个单倍型,系统发育分析结果表明种群间存在一定的遗传分化。综合分析,星豹蛛不同地理种群之间的遗传差异较大,遗传多样性水平较高,进一步从分子遗传学角度证明了星豹蛛成为我国广布种的原因。     

拟环纹豹蛛对白背飞虱的嗅觉反应

采用视觉屏蔽法和Y型嗅觉仪法研究了拟环纹豹蛛Pardosa pseudoannulata.雌性成虫对水稻害虫白背飞虱Sogatella furcifera嗅觉反应.在视觉屏蔽的条件下,拟环纹豹蛛对被刺死猎物的捕食成功率为78.95%,高于没有视觉屏蔽蜘蛛的捕食成功率(68.18%),但2者间差异不显著;而在Y型嗅觉仪中,34.38%拟环纹豹蛛雌性成虫能正确选择猎物的方向,显著高于错误的选择(6.25%).因此,拟环纹豹蛛能依靠嗅觉正确判断猎物的方向而进行捕食活动.     

濒危灌木长叶红砂遗传多样性的RAPD分析

应用RAPD分子标记对濒危灌木长叶红砂(Reaumuria trigyna)种群遗传多样性进行了分析.应用18条随机引物对长叶红砂5个种群的95个个体进行扩增,检测到118个位点,其中多态位点105个.结果表明:长叶红砂种群的多态位点比率(P)为88.98%,显示出长叶红砂种群存在较高的遗传多样性.Shannon多样性指数(0.4966)、Nei基因多样性指数(0.3303)和基因分化系数(Gst=0.1425)的分析结果显示,长叶红砂种群遗传变异大多存在于种群内,种群间的遗传分化占14.25%.聚类分析表明,长叶红砂种群遗传距离与地理距离之间无直接相关关系.遗传多样性水平与物种特性和所处不同群落有关,濒危植物并不一定表现为遗传变异水平的降低.     

RAPD analysis of genetic diversity and population genetic structure of Stipa krylovii Reshov. in Inner Mongolia steppe

Random amplified polymorphic DNA (RAPD) analysis was used to characterize the genetic diversity and population genetic structure of Stipa krylovii populations in Inner Mongolia steppe of North China. Thirteen 10 bp oligonucleotide primers, which generated 237 RAPD bands, were used to analyze 90 plants of five populations from three regions, meadow steppe, typical steppe and desert steppe, from the east to the west. The genetic diversity of Stipa krylovii that was revealed by observed number of alleles (na), expected number of alleles (ne), Nei's diversity index (h), Shannon's diversity index (H), amplificated loci, polymorphic loci and the percentage of polymorphic loci (PPB) increased from the east to the west. The Pearson's correlation analysis between genetic diversity parameters and ecological parameters indicated that the genetic diversity of Stipa krylovii was associated with precipitation and cumulative temperature variations along the longitude (humidity were calculated by precipitation and cumulative temperature). Dendrogram based on Jaccard's genetic distance showed that the individuals from the same population formed a single sub-group. Although most variation (56.85%) was within populations, there was high genetic differentiation among populations of Stipa krylovii, high differentiation within and between regions by AMOVA analysis. Either Nei's unbiased genetic distance (G(ST)) or gene flow (Nm) among pairwise populations was not correlated with geographical distance by Mantel's test (P > 0.05), suggesting that there was no consistency with the isolation by distance model in these populations. Natural selection may have played a role in affecting the genetic diversity and population structure, but habitat destruction and degradation in northern grassland in China may be the main factor responsible for high genetic differentiation among populations, within and among regions.     

Loss of Genetic Diversity of Domesticated Panax notoginseng F H Chen as Evidenced by ITS Sequence and AFLP Polymorphism: A Comparative Study with P. stipuleanatus H T Tsai et K M Feng

In the present study, we evaluated the genetic diversity of Panax notoginseng F H Chen, a domesticated species, and P. stipuleanatus H T Tsai et K M Feng, an endangered wild species in southeastern Yunnan and adjacent areas in Vietnam, using sequences of the internal transcribed spacer (ITS) regions of nuclear ribosomal DNA and amplified fragment length polymorphism (AFLP) markers. Twenty-four accessions from three plantations of P. notoginseng and 51 samples from eight populations of P. stipuleanatus were assayed. A total of 694 bp of partial sequences of 18S, ITS 1, 5.8S, ITS2, and partial sequences of 26S were obtained. No sequence variation was detected within P. notoginseng and nine sites (1.30%) were variable in P. stipuleanatus. Two-thirds of the variable sites were found between Langqiao and other populations. In P. notoginseng, four pairs of AFLP primer combinations generated 312 bands, of which 240 (76.9%) were polymorphic and 60.15% of the polymorphisms were harbored within plantations. Approximately 41.0% and 66.9% of bands were polymorphic in population D7 and 5589, respectively. In P.stipuleanatus, the same four primer combinations produced 346 bands, of which 334 (96.5%) were polymorphic and approximately 62.14% of polymorphisms were maintained within populations. Considerable variations were observed. The percentage of polymorphic bands ranged from 50.2% to 84.9% and the average over populations was 70.9%. Cluster analysis did not show correlation of genetic differentiation with the distinctive leaf morphology of P. stipuleanatus (i.e. one form with bipinnatifid leaflets and the other with undivided leaflets). Because over 40% of genetic variations were maintained among populations and because of the very restricted distribution of P. stipuleanatus, all natural populations of this species should be conserved in situ. Considering that there are variations in P. notoginseng within and among plantations, we suggest establishing a genetic resource conservation garden or reintroducing P. notoginseng into its native habitats in southwestern China. Such reintroduction should be carefully executed after large-scale screening of genetic variation within the species.     

云南灯盏花遗传变异的RAPD分析

运用RAPD (randomamplifiedpolymorphicDNA)技术对云南灯盏花 (Erigeronbrevis capus) 6个居群进行分析 ,研究其遗传变异及遗传结构 ,用外类群紫菀对比分析其亲缘关系。随机挑选 16个引物在 6个居群中共产生 2 33条DNA片段 ,其中 192条带具有遗传多态性 ,约占 82 4 0 %。多态位点百分比PPB、等位基因数A、有效等位基因数Ae、Nei’s基因多样性指数H和Shannon多样性指数I在物种水平分别为 82 4 0 %、 1 82 4 0、 1 30 0 5、0 1896、 0 30 2 1;居群的平均值分别为 5 4 2 3%、 1 5 40 1、 1 2 6 91、 0 16 0 7、 0 2 4 6 0。灯盏花的遗传多样性较丰富 ,基因分化系数Gst值为 0 346 0 ,有 6 5 4 0 %的变异来自居群内 ,6个居群的遗传一致度较高 ,在 0 90 37～ 0 972 3之间 ,平均为 0 94 10。利用UPGMA对 6居群聚类分析 ,结果表明 :丘北居群 (YB)和文山居群 (YX)亲缘关系最近 ,小哨居群 (Y )和新平居群 (YA)次之 ,丘北居群 (YB)和腾冲居群 (ZA)亲缘关系最远。遗传关系与各居群地理分布区间的距离大致成正相关     

Analysis of the Genetic Structure of Sclerotinia sclerotiorum (Lib.) de Bary Populations from Different Regions and Host Plants by Random Amplified Polymorphic DNA Markers

The genetic diversity and genetic structure of a population of isolates of Sclerotinia sclerotiorum (Lib.) de Bary from different regions and host plants were investigated using the random amplified polymorphic DNA (RAPD) method with 20 random decamer primer pairs in order to provide some information on the phylogenetic taxa and breeding for resistance to sclerotinia stem rot. A minimum of three and a maximum of 15 unambiguously amplified bands were generated, furnishing a total of 170 bands ranging in size from 100to 3 200 bp, corresponding to an average of 8.5 bands per primer pair. One hundred and four of these 170bands (61.2%) were polymorphic, the percentage of polymorphic bands for each primer pair ranging from 0.0% to 86.7%. The genetic relationships among the isolates, based on the results of RAPD analysis, were examined. The genetic similarity of all selected isolates was quite high. At the species level, the genetic diversity estimated by Nei's gene diversity (h) was 0.197 and S hannon's index of diversity (I) was 0.300. The unweighted pair-group mean analysis (UPGMA) cluster analysis showed that most isolates from the same regions were grouped in the same cluster or a close cluster. The population of isolates from Hefei (Anhui Province, China) was more uniform and relatively distant to other populations. The Canadian population collected from carrot (Daucus carota var. sativa DC.) was relatively close to the Polish population collected from oilseed rape (Brassica napus L.) plants. There was no relationship between isolates from the same host plants. An analysis of molecular variance (AMOVA) revealed that the percentage of variance attributable to variation among and within populations was 50.62% and 49.38%, respectively. When accessions from China, Europe, and Canada were treated as three separate groups, the variance components among groups,among populations within groups, and within populations were -0.96%, 51.48%, and 49.47%, respectively.The genetic differentiations among and within populations were highly significant (P ＜ 0.001). Similarly, the coefficient of gene differentiation (Gst) in total populations calculated by population genetic analysis was 0.229 4, which indicated that the genetic variation among populations was 22.94%. The gene flow (Nm)was 1.68, which indicated that the gene permutation and interaction among populations was relatively high.     

Genetic differentiation among Hemarthria compressa populations in south China and its genetic relationship with H. japonica

Within and among populations genetic variance of twelve Hemarthria compressa populations and one Hemarthria japonica population from China were analyzed using inter simple sequence repeat (ISSR). Twelve primers amplified a total of 165 genomic DNA fragments across a total of 148 individuals of which 156 were polymorphic (94.55%). 75.76% of the bands were unique to each species, while the average genetic distance (GD) between one population of H. japonica and twelve populations of H. compressa was 0.44, which suggest that there was distinct differentiation between these two species. In H. compressa, twelve primers produced 145 bands across 145 individuals. High genetic diversity was observed at species level. The percentage of polymorphic loci (P) was 86.21% and Shannon's information index of diversity (I) was 0.357. In contrast, there were relatively low levels of genetic diversity within population (P=32.93%, I=0.174). Analysis of molecular variance (AMOVA) showed that a considerable proportion of genetic variation (48.02%) resided among populations. The coefficient of gene differentiation (G(ST)=48.6%) also suggested that there was strong genetic differentiation among H. compressa populations in southern China. An indirect estimate of the number of migrants per generation (N(m)=0.264) indicated that gene flow was low among populations of this species. Relative high clonal diversity was found, and all local genotypes were found.     

利用AFLP分子标记探讨蜡梅种质资源的遗传多样性

利用AFLP分子标记技术,对中国蜡梅种质资源7个野生种群的遗传多样性进行了研究。利用筛选出的3对引物,共扩增出253条谱带,其中218条多态带,多态位点占86.17% ;种群间的基因分化系数为0.2906,说明蜡梅基因多样性主要存在于种群内;种群总的Nei s基因多样性指数为0.2933,Shannon信息多态性指数为0.4487,蜡梅总的遗传多样性水平较高。蜡梅不同种群遗传多样性水平差异较大,种群多态位点百分率在65.44% ～87.16%之间,Nei s基因多样性指数为0.1653 ～0.4012,Shannon信息多态性指数为0.3132 ～0.5603。神农架种群(SN)和保康种群(BK)的遗传多样性水平较高。用NTSYS2.01版软件对样品进行UPGMA聚类分析,结果7个种群并没有按地理距离进行聚类。最后提出要对各蜡梅野生群体采取相应的迁地和就地保护措施。