黔南60份茶树种质资源遗传多样性的SSR分析

为探索黔南野生茶树种质资源的遗传多样性,利用SSR分子标记技术,对黔南60份茶树资源进行了DNA遗传多样性分析。结果表明:15对引物均显示多态性,基因多态性百分率为98.64%。15对SSR引物共扩增出147个观测等位基因和73.778 6个有效等位基因,平均每个引物扩增9.8个观测等位基因,4.918 6个有效等位基因。15个通用位点共产生280种基因型,平均每个位点18.7种基因型。遗传多态信息量变异范围为0.123 9~0.926 8,平均0.572 5,平均观测杂合度、平均期望杂合度和平均Shannons信息指数分别为0.470 0、0.602 3、1.464 4。经聚类分析后,60份材料间遗传相似系数在0.205 1~0.863 6之间,以平均遗传相似系数0.477 5为阈值,可将60份种质资源聚为8个类群,其在分子遗传水平上的分类结果与其材料来源分类的结果并不完全一致,而且材料来源地间遗传距离与地理距离不存在显著的相关性,有少部分同一来源的材料分散在各个类群中。研究认为,黔南茶树资源间的遗传差异较大,遗传基础较宽,具有丰富的遗传多样性。     

野生杏和栽培杏的遗传多样性和遗传结构分析

利用SSR分子标记结合荧光毛细管电泳检测技术,研究了野生杏和栽培杏的遗传多样性和遗传结构,结果显示:27个SSR位点,平均每个位点检测到17.82个等位基因(Na)和7.44个有效等位基因(Ne),平均Shannon's信息指数(I)为2.23,平均期望杂合度(He)和观察杂合度(Ho)分别为0.70和0.52。基于SSR位点,群体水平上平均等位基因数、有效等位基因数、期望杂合度、观察杂合度和Shannon's信息指数分别为6.59、4.15、0.70、0.53和1.50,说明我国杏种质资源遗传多样性丰富,其中野生杏资源遗传多样性明显高于栽培杏资源,野生杏中西伯利亚杏种质遗传多样性最高且具有较多的特异等位基因,而栽培杏中仁用杏遗传多样性最低,特有等位基因较少。聚类分析将供试159份种质分为4组。群体遗传结构分析将159份种质划分为5个类群,分类情况与传统形态指标划分基本一致。通过本研究可知,我国杏资源遗传多样性丰富,遗传结构较为复杂;西伯利亚杏与栽培杏亲缘关系较远;野生普通杏与栽培杏具有类似的遗传结构,推测野生普通杏为栽培杏原始种;仁用杏遗传多样性较低,遗传背景狭窄。本研究结果可为杏资源新品种选育及持续利用提供重要的理论依据。     

利用SSR标记研究茄子种质资源遗传多样性

本研究利用105个SSR分子标记分析了50份茄子种质资源遗传多样性。105对SSR引物中筛选出的20对多态性含量较高的引物,在50份茄子品种组成的群体中共检测出91个等位基因,平均每个基因位点检测到4.55个等位基因。PIC的变幅为0.202 1~0.735 6,平均为0.401 2。根据遗传距离并结合UPGMA聚类分析可将50份种质分为10个类群。SSR分子标记与品种资源性状聚类分析基本一致。     

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。     

加工番茄种质资源的SSR分析

为探明加工番茄种质资源间的亲缘关系,利用SSR标记对20份加工番茄品种及育种材料进行了多样性分析。结果表明:从49对SSR引物中筛选出12对扩增稳定、条带清晰且多态性丰富的引物进行分析,共获得43个位点,多态性位点为37个,多态位点比率86%;供试材料间的遗传相似系数介于0.419~1.000之间,说明加工番茄种质资源间存在一定的遗传差异;通过UPGMA法聚类分析,将20份材料分为3大类群,其中亲缘关系较远的不同类群间及亚类间的种质资源可作为杂交育种的亲本。     

65份野生油茶种质遗传多样性的ISSR和RAPD标记分析

利用ISSR和RAPD标记,对名邛台地野生油茶种质进行遗传多样性分析。从60条简单重复序列引物中筛选出16条引物,在65份样品中共扩增出213条带,其中多态位点为203个,多态位点百分率为95.31%;从30条寡居核苷酸引物中筛选出8条引物,共扩增出105条带,其中多态性位点94个,多态位点百分率为89.52%。结果表明:名邛台地野生油茶种质具有较丰富的遗传多样性,ISSR和RAPD标记可以应用于油茶种质遗传多样性分析。     

利用微卫星标记分析东平湖黄颡鱼的遗传多样性

采用27对鲤微卫星引物对山东东平湖黄颡鱼进行全基因组扫描,结果有19对引物能获得稳定的扩增条带,其中有6个微卫星位点具有多态性。对这6个位点的扩增产物进行分析,结果显示:6个位点共检测到22个等位基因,每个位点的等位基因数从2个到6个不等;平均基因纯合率为41.67%,平均多态信息含量(PIC)为0.488,平均杂合度为0.5833。这表明东平湖黄颡鱼种群结构合理,群体遗传多样性较丰富,种质资源处于安全状态。     

四川核桃良种SSR指纹图谱构建及遗传多样性分析

为构建四川核桃良种指纹图谱,分析遗传多样性,增强品种间的区分能力,该研究利用SSR标记技术,对四川29个核桃良种进行遗传多样性和聚类分析。结果表明:(1)11对SSR引物共检测到121个基因型和80个等位基因,平均每个位点7.273个等位基因和11个基因型。(2)11个位点的平均有效等位基因数为3.644,平均观察杂合度为0.645,平均期望杂合度为0.718,平均香农信息指数为1.518,平均多态信息含量为0.680。(3)采用引物组合法利用引物wga001、wga032和zmz02构建了29个核桃品种的指纹图谱。(4)聚类分析结果表明,29个核桃品种按照品种类型优先聚类,四川本地核桃品种聚类关系与地理来源没有明显的相关性。研究认为,选用的11个SSR标记能够较好地运用于四川核桃品种的遗传多样性研究(PIC0.5);29个四川核桃品种间亲缘关系较近,遗传基础相对较窄。     

基于SSR标记的彩色马铃薯亲缘关系分析及指纹图谱构建

为了探究彩色马铃薯种质资源的遗传背景,该试验共选用22对SSR标记引物,对33份彩色马铃薯品种(系)进行遗传多样性分析以及指纹图谱构建。结果表明:(1)22对引物可扩增得到95个等位位点,其中82个为多态性位点,多态性比率达到86.31%;多态信息量(PIC)从0.168 7(STM1053)到0.991 9(STI033),平均为0.8411。(2)UPGMA聚类分析表明,在相似系数0.71处,33份供试材料分为4个主要聚类群,不同聚类群之间具有较大的遗传差异。(3)利用STM0031、STM0030、STI014、STM1029、STI001共5对SSR标记引物构建了33份彩色马铃薯材料的分子标记指纹图谱。该研究结果为彩色马铃薯育种亲本组配奠定了理论基础,有助于彩色马铃薯种质资源的快速鉴定。     

用SSR标记分析广西香稻与南亚香稻的遗传多样性

利用16对分布于水稻12条染色体上的SSR引物分析78份来自南亚的香稻资源和18份广西种植的香稻的遗传多样性。结果表明:在南亚的香稻资源中,每对引物检测到的等位基因数为3~13个,平均每个位点的等位基因数为5.31个,广西的香稻资源中,每对引物检测到等位基因数2~9个,平均每个位点的等位基因数为3.44个;南亚香稻资源平均多态信息含量(PIC)为0.55,广西香稻资源平均PIC为0.41;南亚香稻资源平均基因多样性(Hs)为0.60,广西香稻资源平均Hs为0.47;说明了南亚香稻资源比广西香稻资源具有更为丰富的遗传多样性。聚类结果表明,大部分的南亚香稻资源或大部分的广西香稻资源各自聚为一类,说明大部分南亚和广西的香稻种质资源存在遗传差异性和地理远缘性。     

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.