共查询到20条相似文献,搜索用时 78 毫秒
1.
2.
用物种多样性指数方法分析兰科植物在福建不同植被地理分区中的分布规律,结果表明:ⅠA1区和ⅡC6区中βWS,Cβ值分别为0.575 0,46.00,均为最大值 CJ,CS值分别为0.269 8,0.425 0,均为最小值 表明ⅠA1区和ⅡC6区兰科植物相异最大。ⅠA2区和ⅠA3区中,βWS,βC值分别为0.322 0,17.50,均为最小值 CJ,CS值分别为0.512 8,0.678 0,均为最大值 表明ⅠA2区和ⅠA3区兰科植物相异最小。不同植被地理分区中兰科植物属数、种数分布规律是:地理位置相隔越远,其共有属数、种数相差越多。 相似文献
3.
4.
5.
通过对小五台山国家级自然保护区的实地调查研究,共记录野生兰科植物16属18种,对其生态环境和应用进行分析,并对其生存状态和保护进行了讨论,应建立野生兰科植物种质资源库,对野生兰科植物进行有效保护。同时要开展野生观赏兰科植物的人工扩繁研究与试验,以便尽快在园林观赏中开发利用这些宝贵的兰科植物资源。 相似文献
6.
以兰科植物为研究对象,从外植体、培养基、植物生长调节剂、有机添加物和其它影响因素等方面简要阐述了其组培研究进展,旨在为其组培研究提供理论依据。 相似文献
7.
兰科植物是我国丰富而珍贵的植物资源,但在园林应用中极为少见。本文介绍了兰科植物的概况,对兰科植物的栽培应用形式提出了新的观点和建议,认为“源于自然,回归自然”是兰科植物发展的正确方向,并对兰科植物在园林中的应用前景和应用中可能出现的问题及解决办法作了详细阐述。 相似文献
8.
龙舌兰科植物资源调查报告 总被引:3,自引:1,他引:3
龙舌兰科植物共有21个属约670个种[1]。分布美洲、非洲、亚洲、太平洋以及大西洋、印度洋的一些岛屿等热带、亚热带地区,其中以墨西哥和美国西南部,尤以两国交界处的索诺拉(sonora)荒漠种类最多。龙舌兰麻类是龙舌兰科所属植物的统称。龙兰麻种类繁多,用途多种多样,有抽取纤维的、提糖酿酒的、药用的、绚丽观赏的……。生境千差万别,从海平线至海拔2100~2400米的高山顶上都有分布[1]。形状各异,千姿百态,差别很大。棱叶龙舌兰麻(Agavepotatorum),植株非常矮小,叶片少而小,最长的叶片也不到30厘米;而暗绿龙舌兰麻(Agaveatr… 相似文献
9.
贵州省兰科植物地理新分布 总被引:1,自引:0,他引:1
[目的]研究兰科植物在贵州省的最新地理分布。[方法]通过调查贵州省的兰科植物种质资源并查阅相关资料,发现有一种未曾记入文献的兰科植物分布在贵州省。[结果]该独花兰的主要形态特征如下:假鳞茎为椭圆形、淡黄色 叶1枚,宽卵状椭圆形,背面紫红色 叶柄长4.2~4.8 cm 花1朵,紫色,葶长10.5 cm,鞘2枚,膜质 花梗和子房长8.6 cm 花瓣呈倒卵状披针形 侧裂片直立,卵状三角形。它主要生长于海拔400~1100(~1800 m)树林下腐殖质丰富的土壤上和山谷中荫蔽的地方,主要分布在江苏西南部、安徽、浙江西部、湖北、湖南、四川南部及陕西南部。[结论]新发现的这一兰科植物为独花兰,是我国特有的单种属植物。 相似文献
10.
11.
Barton N 《Science (New York, N.Y.)》2000,290(5491):462-463
Darwin's theory of evolution by natural selection has long been accepted, but it has not been clear how selection results in reproductive isolation of two populations. In an elegant Perspective, Barton discusses two reports (Higgie et al. and Hendry et al.) showing that selection can cause reproductive isolation between two populations within a dozen or so generations. 相似文献
12.
13.
Sound production by male wolf spiders during courtship is critical for behavioral reproductive isolation of two sibling species. Females only respond to and copulate with conspecific males, and acoustic signals through a substrate are necessary to induce receptivity. No reproductive barriers that could arise during mating (such as genital or mechanical incompatibility) or after mating (infertility) are in effect between the species, since forced interspecific matings produce viable offspring. 相似文献
14.
Saether SA Saetre GP Borge T Wiley C Svedin N Andersson G Veen T Haavie J Servedio MR Bures S Král M Hjernquist MB Gustafsson L Träff J Qvarnström A 《Science (New York, N.Y.)》2007,318(5847):95-97
Interbreeding between species (hybridization) typically produces unfit offspring. Reduced hybridization should therefore be favored by natural selection. However, this is difficult to accomplish because hybridization also sets the stage for genetic recombination to dissociate species-specific traits from the preferences for them. Here we show that this association is maintained by physical linkage (on the same chromosome) in two hybridizing Ficedula flycatchers. By analyzing the mating patterns of female hybrids and cross-fostered offspring, we demonstrate that species recognition is inherited on the Z chromosome, which is also the known location of species-specific male plumage traits and genes causing low hybrid fitness. Limited recombination on the Z chromosome maintains associations of Z-linked genes despite hybridization, suggesting that the sex chromosomes may be a hotspot for adaptive speciation. 相似文献
15.
Reproductive isolation is induced by microorganisms in diverse geographic strains of the flour beetle Tribolium confusum (Coleoptera:Tenebrionidae). The incompatibility between populations is due to nongenetic cytoplasmically inherited factors. Males of infected strains produce no progeny when crossed with females of noninfected strains; however, they produce "normal" numbers of progeny when crossed with infected females. Males from noninfected strains show no reproductive isolation. Infected strains of T. confusum can be cured when tetracycline or other antibiotics are added to the flour medium. "Cured" strains become partially reproductively isolated from all noncured strains including the source strain 相似文献
16.
Woodruff DS 《Science (New York, N.Y.)》1979,203(4380):561-563
Hybrid zones involving Pseudophryne (Anura: Leptodactylidae) provide direct evidence for the operation of postmating reproductive isolating mechanisms in animals in a natural situation. Significant introgression is prevented by hybrid inviability but there is no evidence for the reinforcement of premating isolating mechanisms. These parapatric hybrid zones are of unknown etiology, but are interpreted as being relatively old and persistent. 相似文献
17.
Colonization of new environments should promote rapid speciation as a by-product of adaptation to divergent selective regimes. Although this process of ecological speciation is known to have occurred over millennia or centuries, nothing is known about how quickly reproductive isolation actually evolves when new environments are first colonized. Using DNA microsatellites, population-specific natural tags, and phenotypic variation, we tested for reproductive isolation between two adjacent salmon populations of a common ancestry that colonized divergent reproductive environments (a river and a lake beach). We found evidence for the evolution of reproductive isolation after fewer than 13 generations. 相似文献
18.
19.
20.
广东兰花两种主要病毒的检测 总被引:2,自引:0,他引:2
采用双抗夹心酶联免疫吸附法(DAS-ELISA)对44个兰花病样分别检测建兰花叶病毒(Cymbidium mosaic virus,CyMV )和齿兰环斑病毒(Odontoglossum ringspot virus,ORSV),结果显示,有59.1%的兰花检出CyMV,36.4%的兰花检出ORSV,22.7%的兰花复合感染了CyMV和ORSV.采用一步逆转录聚合酶链式反应(RT-PCR)对24个兰花病样进行检测,结果有83.3%的兰花检出 CyMV,75%的兰花检出ORSV,66.7%的兰花复合感染了CyMV和ORSV,可见RT-PCR检测灵敏度高于ELISA. 相似文献