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951.
Habitat fragmentation has resulted in many species becoming geographically restricted, as dispersal among subsequent isolates becomes compromised. This study investigated the effects of historical fragmentation on the genetic diversity and differentiation of Australia's Bunya Pine (Araucaria bidwillii) using random amplified DNA (RAPD) markers. High diversity characterises all Bunya populations sampled, regardless of population size or degree of isolation, which may be either due to similar effective population size among populations, or the lagging effects of the detection of contemporary genetic signal in long-lived conifer species. Large genetic differentiation characterises the northern and southern populations, although all sampled populations are significantly differentiated from each other. The northern population, at Mt Lewis, is responsible for the majority of variation detected among populations, and as such represents a significant genetic reservoir. The conservation of the genotypes of the Mt Lewis population may be imperative for the future of the species, given predicted models of accelerated climate change over the coming decades.  相似文献   
952.
长白山主要食药用木腐真菌多样性及其保育   总被引:8,自引:0,他引:8  
木腐真菌是真菌多样性的一个重要组成部分 ,它在人类生活和自然生态系统中发挥着特殊的作用 ,在开发利用此类真菌的同时应对它们的保育引起足够重视。真菌多样性的保育有 2种方式 ,即以保护栖息环境为主的就地保育和以菌种保藏、人工驯化为主的异地保育。长白山地区木腐菌的异地保育研究虽然取得了一定的成绩 ,但在就地保育措施方面仍缺乏经验。  相似文献   
953.
Pollen flow of cultivated rice measured under experimental conditions   总被引:15,自引:0,他引:15  
The pollen flow pattern of a cultivated rice variety, Minghui-63, was studied at horizontal and vertical levels under experimental conditions. Data obtained from pollen traps for six designed populations (as pollen sources) at different intervals showed that the dispersal of rice pollen decreased with the increase of distance from pollen sources and that the rice pollen flow was significantly influenced by weather conditions, particularly by wind direction and speed. For a mean wind speed of 2.52 m/s in a downwind direction, the observed distance of rice pollen dispersal was 38.4 m, indicating that rice pollen grains normally disperse at a relatively small range. However, the maximum distance of rice pollen flow could be up to 110 m, using regression analysis of pollen flow and wind speed, when the wind speed reached 10 m/s in this study. The frequency of pollen flow was positively correlated with pollen source size within a given range, suggesting that pollen flow will occur effectively at a considerable rate in rice fields with sufficiently large pollen sources. In addition, many more pollen grains were detected at the height of 1.0–1.5 m than at 2.0 m, indicating that rice pollen mainly disperses at relatively low heights. Results from this study are useful both for minimizing transgene escape from transgenic rice and in situ conservation of wild relatives of rice, as well as for hybrid seed production, where an effective isolation buffer zone needs to be established.  相似文献   
954.
Yancheng Nature Reserve in east China is of great importance to the protection of biodiversity. It is a principal refuge for Red-crowned Cranes (Grus japonensis) and many other rare species, an important station for migrant waterfowls in the Asian Pacific, and a captive breeding base for Milu (Elaphurus davidianus). However, since the late 1980s, serious losses of biodiversity have been emerging in the protected area. In this study, to value objectively and improve management of the Yancheng Nature Reserve, a new approach for conservation management is proposed by virtue of the theories of self-organizing systems, functional group classification and target species selection. According to this approach, biological components in Yancheng Nature Reserve are classified into 10 supporting functional groups, eight target functional groups and 11 subordinate functional groups. Eight target species were selected from those target functional groups, i.e., G. japonensis, E. davidianus, Hydropotes inermis, Larus saundersi, Centropus toulou, Felis bengalensis, Paradoxornis heudei, and Platalea minor. Past observations in Yancheng Nature Reserve illustrate that the new approach is feasible, and this new approach will also benefit the management of the nature reserve.  相似文献   
955.
我国特有植物缙云卫矛濒危机理分析   总被引:3,自引:0,他引:3  
缙云卫矛为我国二级保护植物,仅分布于重庆北碚缙云山和统景镇东温泉公园,皆为旅游胜地。缙云卫矛常以伴生种存在于慈竹林。伴随着旅游业的发展,适宜于缙云卫矛生存的空间环境越来越小,致使该物种处于濒危状态。导致缙云卫矛濒危的原因主要有:(1)物种的生态幅较小,适宜生长在水热条件良好的环境中,(2)形态可塑性较差,对生境的适应能力差;(3)生长发育缓慢,竞争能力较弱;(4)种子萌发率低;(5)人为干扰严重。此外,还讨论了缙云卫矛保护对策。  相似文献   
956.
Primatology in China   总被引:2,自引:2,他引:0  
China is one of the countries with the greatest diversity of nonhuman primate species: 22 species with 30 subspecies, in 6 genera and 3 families. Primatology in China started in 1862, but fruitful study began only in the 1950s. More than 2,000 academic papers have been published, covering systematics, evolution, ecology, etho-ecology, conservation, reproduction and neuroscience. We review primatology in China over the past century, concentrating mostly on systematics, etho-ecology, conservation and reproduction. We aim to share this information with international colleagues and to seek possibilities for collaboration in the future.  相似文献   
957.
Asian Primate Classification   总被引:1,自引:1,他引:0  
In the foreseeable future there is little likelihood of achieving consensus on the number of Asian primate genera and species, and their subspecific composition. There is a more realistic hope of reaching agreement on the number of recognizable subspecies. The latter objective is more urgent because in order to reliably assess generic and specific numbers, it is essential that effective conservation measures are implemented for as many subspecies as possible. This cannot be comprehensively accomplished until their validity is assessed and they are satisfactorily established and defined. The Asian primate classification that we present is the outcome of electronic communication among the co-authors after a workshop, which was especially convened to attempt to determine the number of recognizable primate subspecies and to identify potentially recognizable subspecies. The generic and specific arrangement is a compromise that does not necessarily reflect the individual views of the co-authors: 183 subspecies in 77 species in 16 genera. The 31 subspecies allotted a low credibility rating are almost balanced by the 22 scientifically unnamed populations that may warrant subspecific status.  相似文献   
958.
Cypripedium macranthos var. rebunense is the most famous terrestrial orchid in Japan, since the variety has large beautiful yellowish-white flowers and is threatened with extinction. Establishment of an efficient method for micropropagation is urgently needed. When imbibed mature seeds of the orchid, that had been pre-chilled at 4°C for 3 months, were sown onto Hyponex-peptone medium that contained both α-naphthaleneacetic acid (NAA) and cytokinin, protocorm-like bodies (PLBs) were formed from germinated seeds. Although the growth of PLBs was very slow, plantlets were easily regenerated from the PLBs on hormone-free medium. The PLBs were subcultured eight times along 2 years without loss of ability to regenerate plantlets, and one aggregate of PLBs (ca. 5 mm in diameter) produced ca. 10 plants within a year. A reduction of commercial value through a large-scale micropropagation by this method will be able to prevent illegal collection from the wild populations.  相似文献   
959.
Instructions for Authors   总被引:1,自引:0,他引:1  
Efficient shoot regeneration of Vanda coerulea was achieved using thin shoot tip sections and thidiazuron. Protocorm-like bodies or proliferating shoot buds was observed when thin shoot tip sections were cultured on Vacin and Went's (VW) (1949) basal medium supplemented with 11.35 µM thidiazuron. The highest percentage of protocorm-like bodies (95%) survived and ultimately produced healthy shoots with 2 – 3 leaves when subjected to a 4 week thidiazuron treatment. A culture period longer than 8 weeks with thidiazuron resulted in the formation of fasciated or distorted shoots. Shoots produced roots when cultured on half strength VW basal medium supplemented with 11.42 µM IAA. The well rooted shoots were transferred to pots containing charcoal chips, coconut husk and broken tiles (2:2:1) and a 98% survival rate was achieved.  相似文献   
960.
Conservation strategies for the critically endangered Bermuda skink will require knowledge of genetic variation and population structure. We describe the isolation of six polymorphic microsatellites for this species suitable for use in population genetics studies or for monitoring success of potential breeding programmes. Tissue sampling for DNA extraction involved no blood loss or tail autonomy. Three of these loci cross‐amplify and are polymorphic in a related North American skink (Eumeces fasciatus) and should also be informative for this species.  相似文献   
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