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1.
为探析茶条槭(Acer ginnala)种子和果实表型差异程度及变异规律,该研究采用巢式方差分析、主成分分析、聚类分析等方法,对茶条槭主要分布区内7个种群种子和果实的12个表型性状进行比较研究,分析茶条槭种群间和种群内的表型多样性以及与地理生态因子的关系。结果表明:除种子长/宽(SLW)外,其它11个表型性状在茶条槭种群间和种群内均具有显著差异;各性状平均变异系数(CV)为13.90%,变异幅度为8.14%~32.08%;种群间翅果性状的平均变异系数(15.63%)高于种子性状的平均变异系数(8.71%),表明种子性状的稳定性高于果实性状。主成份分析中,果实形态特征对茶条槭种群表型的贡献率大于种子贡献率。种群间表型分化系数为35.47%,说明种群内变异(64.53%)大于种群间变异(35.47%),暗示变异主要来源于种群内变异。茶条槭种子和果实表型性状受地理生态因子影响较小,主要受自身遗传因素的影响。基于种群间欧式距离的聚类分析将茶条槭7个种群分为2大支,没有严格按照地理距离而聚类,表明茶条槭种群表型性状变异的不连续性。茶条槭不同种群种子和果实具有较高的表型多样性,与其分布范围和生物学特性有关。  相似文献   

2.
五角枫种群表型多样性   总被引:8,自引:2,他引:6  
为揭示五角枫种群的表型分化程度、变异模式及地理变异规律,以山西19个种群为研究对象,采用巢式方差分析、相关分析、聚类分析等方法从形态学角度对五角枫种群的叶片、果实、种子等23个表型性状进行了系统分析。结果表明:(1)五角枫23个表型性状中除果柄长、着生痕、种子长/宽以外,其余20个表型性状在种群间和种群内均存在显著和极显著差异。(2)19个种群的平均变异系数为18.07。叶片、果实、种子的平均表型变异系数依次为:果实19.78%叶片18.77%种子10.25%。(3)五角枫种群间表型分化系数(VST)均值为48.82%,种群内变异(51.18%)与种群间变异(48.82%)基本相当。叶片、果实、种子表型分化系数的平均值为:叶片58.08%果实41.24%种子25.87%。(4)五角枫叶片、果实和种子的信息多样性指数(H)为:叶片6.1079果实5.9118种子5.2855;多样性指数平均值(D)分别为:果实0.9967叶片0.9961种子0.9948。(5)主成分分析结果显示:五角枫种群表型多样性基本来源为:叶片贡献率果实贡献率种子贡献率。(6)五角枫表型变异呈现出以经度和纬度变异并存的趋势,少数表型性状与经度和纬度呈现显著或极显著相关。(7)利用欧氏距离对五角枫种群进行UPGMA聚类分析,将五角枫19个种群划分为两大类群。五角枫种群具有较高的表型多样性,种群间和种群内均存在丰富的表型变异,与其遗传特点和分布生境等密切相关,研究结果为今后五角枫种质资源的保护和利用奠定了基础。  相似文献   

3.
红松种子园种群表型多样性研究   总被引:2,自引:0,他引:2  
童跃伟  唐杨  陈红  张涛  左江  吴健  周莉  周旺明  于大炮  代力民 《生态学报》2019,39(17):6341-6348
为揭示红松(Pinus koraiensis Sieb.et Zucc.)不同种群的表型分化程度和变异规律,以吉林省露水河红松种子园6个种群红松为研究对象,采用巢式方差分析、多重比较、变异系数和聚类分析等方法对红松的叶片、球果和种子共15个表型性状进行了系统分析。结果表明:(1)红松15个表型性状在种群间和种群内均存在着极显著的差异,红松种群遗变异比较丰富,在松属植物中属于中等水平,其中纬度最低的露水河种群在其中10个表型性状均值上表现出最高值;(2)红松种群间的表型分化系数(Vst)均值为12.39%,种群内的变异(87.61%)大于种群间的变异(12.39%),种群内的变异是主要变异来源;(3)各表型性状平均变异系数为13.28%,变幅为6.16%-31.48%,叶片、球果、种子的平均变异系数依次为:球果17.86% > 针叶11.19% > 种子9.87%,种子性状最小,成为最稳定的表型性状,带岭和丰林种群表型性状遗传多样性要高于其他种群;(4)利用欧氏平均距离对红松种群进行UPGMA聚类分析,红松种群的表型性状按照地理距离而聚类,可将红松种子园6个种群分为4类,其表型性状跟地形(东北山脉)有一定的契合。红松种群具有中等水平的表型遗传多样性,种群间和种群内均存在丰富的表型变异,研究结果为顺利开展红松种质资源收集、保存,以及良种选育等工作提供依据。  相似文献   

4.
为探索元宝枫(Acer truncatum)种群间和种群内的表型变异程度和变异规律,以元宝枫主要分布区内15个天然种群150个单株的13个种实性状为研究材料,采用巢氏方差分析、多重比较等分析方法,分析元宝枫种群间和种群内的表型多样性及其与地理生态因子间的相关性。结果表明:元宝枫果实、种子性状在种群内、种群间存在丰富的变异,各种实性状在种群内、种群间均具有极显著差异;元宝枫种群间表型分化系数为19.87%,种群内变异(80.13%)大于种群间变异(19.87%),种群内变异是变异的主要来源;元宝枫各性状平均变异系数为13.34%,变异幅度为8.98%~21.45%,种群间种子性状的平均变异系数(11.46%)低于种群间翅果性状的平均变异系数(14.52%),表明种子性状的稳定性高于果实性状。主成分分析结果显示,果实形态对元宝枫种群表型的贡献率大于种子贡献率。性状间相关性分析结果显示,翅果越大则种子越大,果翅角度性状与果实、种子大小皆无显著关系,推测其为独立因子。果实形态变异主要表现为经向变异,而种子性状无显著变异。利用种群间聚类分析将元宝枫15个种群分为三大类群。种群间与种群内多层次的变异模式为元宝枫种质资源保护与利用提供依据。  相似文献   

5.
为了明确我国枫香树(Liquidambarformosana)种子与果实表型变异程度和变异规律,采用方差分析、相关分析和回归分析等方法对36个天然种群枫香树的10个种子与果实的表型性状在种群间和种群内表型变异和地理变异模式进行探讨。研究结果表明,枫香树平均表型分化系数为57.55%,种群间的变异是其表型变异的主要来源;种子和果实表型性状的变异丰富,变异幅度为10.05%–24.31%,平均变异系数为15.83%;不同种群间变异差别明显,安福种群平均变异系数最大(16.73%),建阳种群平均变异系数最小(11.48%)。枫香树多数种子与果实表型性状在地理变化上是随机的,地理相近种群在表型上没有显著相关性。地理气候因子中1月平均气温、海拔和纬度对种子与果实性状起主要的影响。种子与果实性状与海拔相关分析表明,枫香树种子长宽比随海拔的升高而减小,种子长宽比可以推测种群所在的海拔高度。探讨枫香树种群表型多样性,可为野生优异种质的收集、多目标品种选育等工作提供依据。  相似文献   

6.
《植物生态学报》2018,42(7):752
为了明确我国枫香树(Liquidambar formosana)种子与果实表型变异程度和变异规律, 采用方差分析、相关分析和回归分析等方法对36个天然种群枫香树的10个种子与果实的表型性状在种群间和种群内表型变异和地理变异模式进行探讨。研究结果表明, 枫香树平均表型分化系数为57.55%, 种群间的变异是其表型变异的主要来源; 种子和果实表型性状的变异丰富, 变异幅度为10.05%-24.31%, 平均变异系数为15.83%; 不同种群间变异差别明显, 安福种群平均变异系数最大(16.73%), 建阳种群平均变异系数最小(11.48%)。枫香树多数种子与果实表型性状在地理变化上是随机的, 地理相近种群在表型上没有显著相关性。地理气候因子中1月平均气温、海拔和纬度对种子与果实性状起主要的影响。种子与果实性状与海拔相关分析表明, 枫香树种子长宽比随海拔的升高而减小, 种子长宽比可以推测种群所在的海拔高度。探讨枫香树种群表型多样性, 可为野生优异种质的收集、多目标品种选育等工作提供依据。  相似文献   

7.
滇北球花报春天然群体表型变异研究   总被引:7,自引:0,他引:7  
滇北球花报春(Primula denticulata ssp. sinodenticulata)的早春蓝紫色球状花序具有独特的观赏价值, 但由于多种因素的影响, 其天然群体正在逐渐减少。为评价其遗传多样性水平, 我们对滇北球花报春10个天然群体进行了表型性状变异研究。结果表明: 滇北球花报春8个表型性状在群体间和群体内均存在极显著差异, 变异系数(CV)在4.73–9.90%之间, 表型分化系数(Vst)在0.1541–0.4069之间, 平均值为0.2854, 群体内的变异是表型变异的主要来源。根据8个表型性状的UPGMA聚类分析将10个天然群体划分为3类。依本研究结果, 在对滇北球花报春种质资源保护时进行就地保护是十分必要的, 并且应该优先保护表型变异较为丰富的天然群体。  相似文献   

8.
山苍子天然种群叶片和种实性状的表型多样性   总被引:4,自引:0,他引:4  
为揭示山苍子(Litsea cubeba)天然种群叶片和种实性状的表型变异程度及其变异规律,调查了长江以南7个省份共10个天然种群的叶片和种实性状,并对其多样性进行分析。结果表明:1)山苍子的叶片和种实性状在种群间和种群内存在极其丰富的多样性,各性状表型分化系数(Vst)均值为60.19%,种群表型性状分化以种群间变异为主;2)果实形态、叶片形态、果实重和种子重4类性状的Vst均值分别为51.27%、66.66%、54.57%和72.29%;平均变异系数(CV)分别为6.60%、16.91%、19.71%和13.40%;果实形态的表型分化系数和变异系数最小,表明其性状最为稳定;3)10个表型性状间多数呈显著或极显著相关,性状与地理气候因子的相关性较差;4)系统聚类将10个种群共分为4类,种群间的分类并没有依地理距离而聚类,表型性状的Mahalanobis距离与地理距离的相关不显著(r=0.042,P=0.821),进一步表明山苍子叶片和种实性状的变异在空间上是不连续性的。研究结果为今后山苍子种质资源的保存和育种策略的制定奠定基础。  相似文献   

9.
为揭示长柄扁桃(Amygdalus pedunculata)天然种群的表型多样性特点,通过方差分析、相关分析、聚类分析和t检验等方法对7个天然种群14个表型性状种群间和种群内的表型变异特征和地理变异模式进行了探讨。结果表明:长柄扁桃种群内变异为40.91%,种群间变异为35.29%,种群内大于种群间,种群内变异是主要变异来源;其平均表型分化系数为45.90%,各表型性状平均变异系数为15.59%,変幅9.39%–31.98%,表型变异在种群内和种群间均非常丰富。年平均气温、纬度、无霜期、经度和海拔5个主要地理生态因子对长柄扁桃表型性状影响显著或极显著,平均气温和无霜期是不同立地长柄扁桃表型差异的主要影响因子。主成分分析和聚类分析将7个种群区划为两大类,其中山地的长柄扁桃叶多为近圆形至长圆形,果多为近球形,果柄较短,果肉较厚,核多为宽卵形至圆球形;沙地的长柄扁桃叶多为长椭圆形或卵状披针形,果为卵球形,果柄较长,果肉较薄,核近宽卵形。探讨长柄扁桃天然种群表型多样性,可为顺利开展野生资源收集、良种选育等工作提供依据。  相似文献   

10.
白皮松天然群体种实性状表型多样性研究   总被引:77,自引:4,他引:73  
在白皮松天然林分布区共抽取了13个群体,分别测量了5个种实性状。方差分析表明:白皮松种实性状在群体间和群体内存在广泛的变异,5个性状在群体间的F值为2.44~14.68,群体内的F值为7.48~44.53,差异均达显著或极显著水平。群体内的方差分量接近80%,是白皮松表型遗传变异的主要部分。群体间的表型分化系数VST=22.8%,与其他松类树种相比,分化水平处于中等偏上。各群体内变异系数和相对极差存在显著或极显著差异,根据二者的多重比较,可将13个群体按群体内表型变异程度分为4组。种子性状地理梯度变异明显, 呈东北—西南走向。种子3个性状(亲代)的表型变异系数与子代的2年生苗高和地径、1年生苗的全干重之间达到或接近显著相关。  相似文献   

11.
Systematic significance of mature embryo of bamboos   总被引:1,自引:0,他引:1  
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.  相似文献   

12.
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.  相似文献   

13.
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.  相似文献   

14.
The Drosophila Pax6 homolog twin of eyeless (toy) is so far the first zygotically expressed gene involved in eye morphogenesis in Drosophila. The study of its expression during embryogenesis is therefore informative of the initial events of eye development in Drosophila. We have analyzed how the initial expression domain of toy at cellular blastoderm is regulated. We show that the three maternal patterning systems active in the cephalic region (the anterior, terminal and dorsal-ventral systems) cooperate with zygotically activated gap genes to shape the initial expression domain of toy. Whereas Bicoid, Dorsal and Torso signaling synergistically act as activators, Hunchback, Knirps and Decapentaplegic act as repressors.  相似文献   

15.
16.
Twenty three species in 11 genera were examined in the field to determine hosts. OnlyStriga asiatica andSeymeria cassioides have a narrow host range being restricted to grasses and pines, respectively. These are the only species which cause pronounced and sometimes serious host damage. The other species attach to a great diversity of hosts.  相似文献   

17.
Lactobacilli play a distinctive role in the microbial balance of the chicken gut. In experiments simulating the chicken crop, the antagonism of lactobacilli against Enterobacteriaceae and Salmonella typhimurium was demonstrated and was attributed to lactic acid production. Moreover, adhesion to the crop epithelium was a common characteristic of intestinal lactobacilli. As opposed to salmonellas, lactobacilli were sensitive to deconjugated bile salts at 2.5mm. This sensitivity could lower their chance of proliferation in the small bowel of the chicken tract.The authors are at the Laboratory of Microbial Ecology, Faculty of Agricultural Sciences, State University of Gent, Coupure L., 653, B-9000 Gent, Belgium.  相似文献   

18.
Intracellular cysteine aspartate-specific proteases (caspases) play both signaling and effector roles in realizing the program of cell death. Caspases function as proteolytic cascades unique for each cell type and signal triggering apoptosis. All parts of the proteolytic cascades are duplicated and controlled by feedback signals. Amplification cycles between pairs of caspases (the third and the sixth, the ninth and the third, the twelfth and the sixth, and others) help multiply the initial apoptotic signal. The presence of physiological inhibitors of apoptosis that directly interact with caspases creates a multilevel regulatory network of apoptosis in cell. The caspase proteolytic cascades are also regulated by sphingolipid secondary messengers, among them ceramide, sphingosine, and their phosphates. Moreover, an association of the caspase signaling with ubiquitin-dependent proteolysis is shown in cells. In particular, the use of extracellular activators and inhibitors of caspases allows irreversible activation of apoptosis in tumor cells or the prevention of apoptosis in cortical neurons under neurodegenerative diseases.  相似文献   

19.
李腾  唐启明  韦玉梅  赵建成  李敏 《广西植物》2021,41(8):1372-1390
通过对采自广西24个县(市)的1 147份青藓科植物标本的逐一鉴定及相关文献的查阅,确认有广西青藓科植物11属、44种,其中包括广西青藓科植物新记录属1属,即拟异叶藓属(Pseudokindbergia),新记录种7种,分别为匐枝青藓(Brachythecium procumbens)、阔叶尖喙藓(Oxyrrhynchium latifolium)、泛生尖喙藓(O. vagans)、拟异叶藓(Pseudokindbergia dumosa)、华东细喙藓(Rhynchostegiella sinensis)、长肋拟青藓(Sciurohypnum populeum)和弯叶拟青藓(S. reflexum)。该文提供了修订后的广西青藓科植物名录,并对其中的新记录属、种的主要形态学识别特征、生境和地理分布等进行了详细描述。  相似文献   

20.
The role of the C-terminal domain of rhodopsin in the activation of transducin was studied. The treatment of photoreceptor membranes with trypsin, thermolysin, and Asp-N-endoprotease led to the respective rhodopsin species devoid of 9, 12-, or 19-aa C-terminal fragments. It was shown that the removal of 9-aa fragment by trypsin does not affect the catalytic activity of the receptor, whereas the thermolysin-induced truncation of the rhodopsin C-terminus by 12 aa about 1.5-fold enhances its activity. The Asp-N-endoprotease-assisted removal of 19 aa (i.e., the shortening by seven more C-terminal aa) virtually unchanges catalytic activity of the resulting truncated rhodopsin compared to the preparation truncated with thermolysin. These results suggest that the part of the rhodopsin C-terminal fragment between the sites of its cleavage by trypsin and thermolysin (Val337–Ser338–Lys339) inhibits the signal transduction from rhodopsin to the next component of visual cascade.  相似文献   

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