山茱萸种质资源的ISSR遗传多样性分析与初级核心种质库的构建

采用ISSR 标记技术对不同来源地的48份山茱萸种质资源的遗传多样性进行了分析,并依据最小遗传距离逐步抽样法构建了该初级核心种质资源库.结果显示:筛选出的13个多态性引物共扩增出190个位点,多态性位点比率达93.16%,平均Shannon信息指数(I)为0.402 5,平均Nei's基因多样性指数(H)为0.259 4,平均有效等位基因数(NE)为1.425 0.聚类分析表明,种质间的遗传相似系数介于0.65～0.90之间,除个别种质外,48个种质聚类结果与地区来源有较高的一致性.随着抽取种质数目的减少,多态性比率明显降低,但种质库遗传多样性参数变化较小;抽样3构建的初级核心种质库最具代表性,抽样数是抽样前的30%左右,多态位点比率是抽样前的96.0%.     

籽用西瓜种质资源SSR分析及初级核心种质库构建

采用SSR分子标记技术对50份不同来源的籽用西瓜材料进行遗传多样性研究,并基于SSR分子标记聚类分析采用最小距离逐步抽样法构建籽瓜初级核心种质库。研究表明：（1）从106对SSR随机引物中筛选出扩增条带清晰、多态性高的31对引物,共得到138条清晰可辨条带,其中多态性条带115条,占83.33%,平均Shannon’s信息指数(I）为0.419 3,平均Nei’s多样指数(h）为0.272 4,平均有效等位基因数(N_e）为1.458 0,平均等位基因数(N_a）为1.981 4,说明50份籽瓜种质具有丰富的遗传多样性。（2）用NTsys2.10e软件对种质资源聚类分析表明,种质间的遗传相似系数介于0.57~0.91之间,其中来源地相同的个别种质间遗传相似系数却很小,而来源地不同的个别种质间的遗传相似系数却很高。（3）采用最小距离逐步抽样法,按70%、60%、50%、40%、30%、20%、10%的比例抽样后,各个核心子集遗传多样性指数总体上变化不明显,但各抽样比例相比,以抽样比例20%获得10份初选种质的 N_e、 h和 I达到最高值,说明抽样20%构建的初级核心种质对原始种质具有很好的代表性。     

福建省枳椇种质资源遗传多样性RAPD分析

建立和优化枳椇Hovenia acerba的RAPD反应体系,并对福建省12个种源地35份枳椇材料进行遗传多样性及亲缘关系研究。利用筛选出的10个RAPD引物共检测基因组DNA中193个位点,其中多态性位点161个(83.42%)。供试材料观测等位基因数(Na)1.8342、有效等位基因数(Ne)1.4155,Nei’s基因多样性(H)0.2493,Shannon多样性指数(I)0.3822。以遗传相似系数0.754为阈值,可将35份枳椇分成五大组。RAPD标记可有效揭示福建省枳椇种质资源的遗传多样性,所测枳椇种质资源遗传多样性丰富,极具开发利用价值。     

中型狼尾草种质资源遗传多样性的ISSR分析

运用ISSR标记对采自云南的25份野生种质和4份驯化新品系中型狼尾草材料进行遗传多样性分析。结果显示:(1)50条ISSR引物中共筛选出10条能扩增出清晰条带且多态性明显的引物,29份材料DNA共获得72个扩增位点,其中多态性位点62个,多态性比率为87.4%,平均每条引物扩增位点为7.2个;平均观察等位基因数(Na)、有效等位基因数(Ne)、Shannon多样性信息指数(I)和Nei’s基因多样性指数(H)分别为1.861 1、1.742 8、0.561 0和0.395 9;种质材料间的遗传相似性系数变幅为0.236~0.903,表现出丰富的遗传多样性。(2)利用UPGMA聚类分析,以遗传相似系数0.51为界,29份材料划分为4大类,但Mantel检测表明29份种质材料的遗传聚类和地理距离之间不存在显著的正相关关系(r=0.437 0,P=0.204 6)。研究结果首次从分子水平揭示了中型狼尾草的遗传多样性和变异水平,为合理地引种、驯化、保护和利用中型狼尾草野生资源提供了重要的参考依据和数据支持。     

24份铁皮石斛种质资源的ISSR分析

本文采用ISSR分子标记方法分析了24份不同地区来源铁皮石斛种质资源的遗传多样性和亲缘关系。利用筛选出的7条ISSR引物对铁皮石斛基因组DNA进行PCR扩增,共获得92条DNA条带,其中多态性条带84条,多态性比率(PPB)为91. 3%。利用POPGENE 32软件计算得出平均观察等位基因(Na)为1. 913 0,平均有效等位基因数(Ne)为1. 528 3,平均Nei’s基因多样性指数(H)为0. 310 0,平均Shannon’s信息指数(I)为0. 465 0。利用NTSYS-pc软件得出24份试验材料的遗传相似系数(GS)范围为0. 478 3～0. 913 0,聚类分析结果表明24份人工栽培居群的铁皮石斛分为3类,暗示铁皮石斛种质具有较为丰富的遗传多样性。该研究为全面掌握铁皮石斛种质资源遗传背景,选育、引种和推广优良铁皮石斛品种奠定了可靠的理论基础。     

皂荚种质资源SCoT遗传多样性分析及指纹图谱的构建

采用SCoT标记分析了18个皂荚种质的遗传多样性,并采用UPGMA法对18个皂荚种质进行了聚类分析。在此基础上,通过筛选出的多态性条带构建了18个皂荚种质的SCoT指纹图谱。扩增结果表明:从51个SCoT引物中筛选了15个引物进行PCR扩增,共扩增出226条带,其中多态性条带216条,多态性比率为96.61%。各引物多态性信息含量(PIC)、观测等位基因数(Na)、有效等位基因数(Ne)、Nei’s基因多样性指数(H)和Shannon’s信息指数(I)的平均值分别为0.875 9、1.964 9、1.440 1、0.272 6、0.426 1。18个皂荚种质的遗传相似系数在0.491 4~0.938 1之间,表明供试材料之间具有较丰富的遗传多样性。聚类分析结果表明:在遗传相似系数为0.60处可将18个皂荚种质分为3组,其中野皂荚单独为一组,山皂荚和皂荚-T聚为一组,其它皂荚材料聚为一组。利用3个引物扩增的8个多态性位点构建了18份皂荚种质资源的DNA指纹图谱,可以将其区分并精准鉴定。该研究结果为皂荚种质的鉴定和新品种选育提供了一定的理论依据。     

新疆枸杞种质资源遗传多样性分析及DNA指纹图谱构建

利用SCoT分子标记对新疆枸杞种质资源进行遗传多样性分析和DNA指纹图谱构建,为杂交育种和种质鉴定提供理论依据。结果显示:9条SCoT引物扩增出条带256条,其中219条为多态性条带,多态性比率达85.62%,多态性信息含量(PIC)值变化范围在0.77~0.91之间,平均值为0.85,观测等位基因数(Na)、有效等位基因数(Ne)、Nei's基因多样性指数(H)和Shannon信息指数(I)的平均值分别为1.8562、1.4350、0.2611、0.3989,聚类分析表明,遗传相似系数变化范围在0.5938~0.8398之间,在遗传相似系数为0.66和0.71处,可将30份材料分别分为2大类和4个亚类,主坐标分析结果和聚类结果基本一致,同时利用5条多态性SCoT引物构建了30份材料的DNA指纹图谱。新疆枸杞种质资源遗传多样性水平较高,且SCoT分子标记适于新疆枸杞种质资源遗传多样性分析和DNA指纹图谱构建,该研究结果为新疆枸杞种质资源评价、鉴定和新品种选育奠定了基础。     

中国灌木辣椒种质遗传多样性的SRAP和SSR分析

应用SRAP和SSR分子标记对8份辣椒种质进行了遗传多样性分析,结果表明,15对SRAP引物组合共扩增出321条带,平均每对引物扩增出21.40条,多态性位点比率为72.90%;18对SSR引物共扩增出109条带,平均每对引物扩增出6.06条,多态性位点比率为98.17%。与SRAP比较,SSR检测到的Shannon多样性指数(I)、观测等位基因数(Na)和有效等位基因数(Ne)等遗传多样性参数都较大,说明SSR有更高的多态性检测效率。基于SRAP的聚类与基于SSR的聚类之间存在极显著正相关,且都能将中国灌木辣椒种质与美洲灌木辣椒种质及一年生辣椒种质有效区分。     

新疆石榴种质资源遗传多样性的SRAP分析

采用SRAP分子标记技术,对21份新疆石榴品种的遗传多样性与亲缘关系进行分析。从36对引物组合中筛选出16对扩增条带清晰、多态性高的引物组合分析供试材料,共检测出271个位点,其中194个为多态性位点,多态性比率达71.59%,平均每对引物组合产生16.94个位点和12.13个多态性位点。21份石榴样品间的相似性系数为0.63~0.89,平均为0.77。UPGMA聚类结果显示,在相似性系数为0.776时,21份材料可被分为5个类群。新疆石榴品种间平均观察等位基因数(Na)、有效等位基因数(Ne)、Neis基因多样性指数(H)及Shannons信息指数(I)分别为1.712 2、1.352 8、0.199 9及0.310 5。研究表明,新疆喀什地区石榴品种的遗传多样性最为丰富;SRAP聚类结果与石榴的表型特征存在一致性,且SRAP分子标记技术是研究石榴遗传多样性简单而有效的手段。     

基于SRAP标记的甜瓜耐盐种质资源遗传多样性分析

研究不同耐盐程度甜瓜种质资源的亲缘关系和遗传多样性,为甜瓜种质资源有效利用提供理论依据。该试验以不同耐盐程度的27个甜瓜品种为材料,利用SRAP标记分析甜瓜种质资源的遗传多样性,从364对引物组合中筛选出24对扩增清楚且多态性丰富的引物,共扩增出415个清晰的位点,其中多态性位点241个,多态比率达58%。平均观测等位基因数(Na)为1.588 0,平均有效等位基因数(Ne)为1.347 0,平均Nei's基因多样性指数(H)为0.201 3,平均Shannon's信息指数(I)为0.301 0,表明供试甜瓜具有丰富的遗传多样性。UPGMA聚类结果显示:遗传相似系数在0.36～1.00之间,遗传相似性系数在0.72时,可将27个甜瓜品种划分为4个类群,耐盐型甜瓜在其中3个类群有分布,中等耐盐型甜瓜在4大类群中均有分布,盐敏感型均集中在第Ⅰ类群,表明耐盐型和中等耐盐型甜瓜种质的遗传多样性比盐敏感型种质丰富。遗传相似系数与UPGMA聚类结果的Cophentic矩阵相关系数为0.749,说明聚类分析结果较准确。研究认为,耐盐型甜瓜的遗传多样性较丰富,要得到耐盐的杂种优势品种,需要融入更多遗传关系较远的新种质。     

Foreign exploration for Scirtothrips perseae Nakahara (Thysanoptera: Thripidae) and associated natural enemies on avocado (Persea americana Miller)

Scirtothrips perseae Nakahara was discovered attacking avocados in California, USA, in 1996. Host plant surveys in California indicated that S. perseae has a highly restricted host range with larvae being found only on avocados, while adults were collected from 11 different plant species. As part of a management program for this pest, a “classical” biological control program was initiated and foreign exploration was conducted to delineate the home range of S. perseae, to survey for associated natural enemies and inventory other species of phytophagous thrips on avocados grown in Mexico, Guatemala, Costa Rica, the Dominican Republic, Trinidad, and Brazil. Foreign exploration efforts indicate that S. perseae occurs on avocados grown at high altitudes (>1500 m) from Uruapan in Mexico south to areas around Guatemala City in Guatemala. In Costa Rica, S. perseae is replaced by an undescribed congener as the dominant phytophagous thrips on avocados grown at high altitudes (>1300 m). No species of Scirtothrips were found on avocados in the Dominican Republic, Trinidad, or Brazil. In total, 2136 phytophagous thrips were collected and identified, representing over 47 identified species from at least 19 genera. The significance of these species records is discussed. Of collected material 4% were potential thrips biological control agents. Natural enemies were dominated by six genera of predatory thrips (Aeolothrips, Aleurodothrips, Franklinothrips, Leptothrips, Scolothrips, and Karnyothrips). One genus each of parasitoid (Ceranisus) and predatory mite (Balaustium) were found. Based on the results of our sampling techniques, prospects for the importation of thrips natural enemies for use in a “classical” biological control program in California against S. perseae are not promising.     

Phylogeny of cardinalfishes (Teleostei: Gobiiformes: Apogonidae) and the evolution of visceral bioluminescence

The cardinalfishes (Apogonidae) are a diverse clade of small, mostly reef-dwelling fishes, for which a variety of morphological data have not yielded a consistent phylogeny. We use DNA sequence to hypothesize phylogenetic relationships within Apogonidae and among apogonids and other acanthomorph families, to examine patterns of evolution including the distribution of a visceral bioluminescence system. In conformance with previous studies, Apogonidae is placed in a clade with Pempheridae, Kurtidae, Leiognathidae, and Gobioidei. The apogonid genus Pseudamia is recovered outside the remainder of the family, not as sister to the superficially similar genus Gymnapogon. Species sampled from the Caribbean and Western Atlantic (Phaeoptyx, Astrapogon, and some Apogon species) form a clade, as do the larger-bodied Glossamia and Cheilodipterus. Incidence of visceral bioluminescence is found scattered throughout the phylogeny, independently for each group in which it is present. Examination of the fine structure of the visceral bioluminescence system through histology shows that light organs exhibit a range of morphologies, with some composed of complex masses of tubules (Siphamia, Pempheris, Parapriacanthus) and others lacking tubules but containing chambers formed by folds of the visceral epithelium (Acropoma, Archamia, Jaydia, and Rhabdamia). Light organs in Siphamia, Acropoma, Pempheris and Parapriacanthus are distinct from but connected to the gut; those in Archamia, Jaydia, and Rhabdamia are simply portions of the intestinal tract, and are little differentiated from the surrounding tissues. The presence or absence of symbiotic luminescent bacteria does not correlate with light organ structure; the tubular light organs of Siphamia and chambered tubes of Acropoma house bacteria, those in Pempheridae and the other Apogonidae do not.     

Biological control of three floating water weeds,<Emphasis Type="Italic">Eichhornia crassipes,Pistia stratiotes</Emphasis>, and <Emphasis Type="Italic">Salviniamolesta</Emphasis> in the Republic of Congo

Since 1999, four specific weevils (Coleoptera, Curculionidae) were released in the Republic of Congo against three exotic floating water weeds: Neochetina eichhorniae Warner and N. bruchi Hustache against water hyacinth, Neohydronomus affinis Hustache against water lettuce, and Cyrtobagous salviniae Calder and Sands against water fern. Recoveries of exotic weevils were made from all 24 release sites except one, and all four species have established and spread (up to 800 km for water hyacinth weevils). Within a few years of releases, control of water fern and water lettuce was such that fishing and navigation could be resumed, while reductions of water hyacinth populations were only beginning.     

A molecular phylogeny of Hebeloma species from Europe

In order to widen the scope of existing phylogenies of the ectomycorrhizal agaric genus Hebeloma a total of 53 new rDNA ITS sequences from that genus was generated, augmented by sequences retrieved from GenBank, and analysed using Bayesian, strict consensus and neighbour joining methods. The lignicolous Hebelomina neerlandica, Gymnopilus penetrans, and two species of Galerina served as outgroup taxa. Anamika indica, as well as representatives of the genera Hymenogaster and Naucoria, were included to test the monophyly of Hebeloma, which is confirmed by the results. Hebeloma, Naucoria, Hymenogaster and Anamika indica cluster in a strongly supported monophyletic hebelomatoid clade. All trees largely reflect the current infrageneric classification within Hebeloma, and divide the genus into mostly well-supported monophyletic groups surrounding H. crustuliniforme, H. velutipes, H. sacchariolens, H. sinapizans, and H. radicosum, with H. sarcophyllum being shown at an independent position; however this is not well supported. The section Indusiata divides with strong support into three groups, the position of the pleurocystidiate Hebeloma cistophilum suggests the possible existence of a third subsection within sect. Indusiata. Subsection Sacchariolentia is raised to the rank of section.     

Taxonomic status of the species of the green algal genusNeochloris

Komárek has recently reviewed the various species assigned to the green algal genusNeochloris Starr (Chlorococcales, Chlorococcaceae) and removed those with uninucleate vegetative cells to a new genus,Ettlia. Watanabe & Floyd, unaware ofKomárek's work, also reviewed the species ofNeochloris and distributed them among three genera—Neochloris, Chlorococcopsis gen. nov., andParietochloris gen. nov.—on the basis of details of the covering of the zoospore and the arrangement of the basal bodies of the flagellar apparatus. This paper reconciles these two treatments and makes additional recommendations at the ranks of genus, family, order, and class.     

Demographic characteristics of an intertidal bay goby (Lepidogobius lepidus)

Synopsis In a fourteen month study (May 1976 – June 1977) I examined the following characteristics of an intertidal bay goby (Lepidogobius lepidus) in Morro Bay, California, U.S.A.: annual and seasonal patterns of abundance, age composition and growth rates, survivorship and mortality patterns, and the reproductive cycle for female gobies. Fishes were collected with the aid of quinaldine and otoliths and ovaries removed. Age and growth rates were estimated from otolith annuli using a back calculation formula and a Brody-Bertalanffy growth curve. Mortality rates were derived using the methods of Heincke (1913), Robson & Chapman (1960), mean age, and a catch curve (Ricker 1975). A gonad index was used to describe the annual reproductive cycle. Results indicated that abundance fluctuated seasonally and that these fluctuations appeared to be caused by reproductive emigrations. Bay gobies reached an age of 7+ and a standard length of 87 mm. Growth was relatively constant (6 mm yr⁻¹) until age 5, at which point it began to decline. The mean rates of survivorship, mortality, and instantaneous mortality were 0.75, 0.25, and 0.29 respectively. Mortality rates for individual age classes ranged from 0.13 to 0.51 and increased with age. This stock appears to reproduce mainly during the winter.     

Die GattungKarschia — Bindeglied zwischen bitunicaten Ascomyceten und lecanoralen Flechtenpilzen?

The genusKarschia, in the earlier sense, including saprophytes and parasites on lichens, has been thought to be a non-lichenized parallel genus of the lichen genusBuellia. Modern workers included it on the one hand inBuellia, on the other hand combined it with bitunicate ascomycetes. It is now proved thatKarschia is heterogeneous and contains but superficially similar members both of the genusBuellia of theLecanorales and of typical or masked bitunicateAscomycetes. Therefore, it can not be regarded as a link betweenLecanorales andDothideales. The type species ofKarschia belongs to theDothideales.

     

Systematic significance of mature embryo of bamboos

The mature embryo of seven species belonging to five genera of Indian bamboos is described. In all these the basic pattern of embryo organisation is same: the scutellar and coleoptilar bundles are not separated by an internode, the epiblast is absent, the lower portion of the scutellum and the coleorhiza are separated by a cleft and the margins of embryonic leaves overlap. The features unique to fleshy fruited bamboos are: presence of a massive scutellum, the juxtaposition of plumule and radicle and the occurrence of a bud in the axil of the coleoptile. The fleshy fruit bearing bamboos should be classified into one group, the tribeMelocanneae. Evidence is provided to recognise additional groups in the subfamilyBambusoideae.