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61.
黄山钓桥青冈种群的交配系统与近交衰退   总被引:21,自引:2,他引:19  
陈小勇  宋永昌 《生态学报》1997,17(5):462-468
采用垂直板型不连续聚丙烯酰胺凝胶电泳检测了黄山钓桥青冈种群的遗传变异、交配系统及近交衰退程度。黄山钓桥青冈群维持有中等程度的遗传变异,多态位点百分比和期望杂合度分别为50%和0.1814。采用POD-2、EST-1和EST-2等3个多态位点,利用MLT程序估计的花粉库和母株基因频率之间存在一些差异,可能是由于成熟个体花粉产量不同和种群内个体非随机分布造成的。单位点杂交率平均为0.392,略高于多位  相似文献   
62.
华东地区青冈种群的遗传多样性及遗传分化   总被引:21,自引:0,他引:21  
采用垂直板型聚丙烯酰胺凝胶电泳测定了华东地区6个青冈(Cyclobalanopsis glauca(Thunb.)Oerst.)种群的遗传多样性和遗传分化程度以及基因流。青冈种和种群水平都维持有较高的遗传多样性,期望杂合度分别为0.2252和0.2126,观察杂合度分别为0.1661和0.1771。种群间的遗传分化程度较低,分化度仅为5.6%,种群间的遗传一致度和遗传距离的均值分别为0.9729和0.0276。种群间的分化时间为1.4~27万年。基因流分别为4.21和20.49。  相似文献   
63.
采用年轮分析法对岩溶区青冈栎样树年轮和生物量进行测定并对其群落生物量进行估算。研究结果显示,青冈栎平均树龄46a,平均胸径20.52cm,单位地上生物量为98.668t.hm-2。随着植株的生长,胸径越大则生物量越大,两者形成明显的幂函数关系。d、e、f、g和h样树地上生物量为2.884、22.567、108.183、134.314和379.799kg,生物量分配状况是主干>枝条>树叶,大部分的生物量分配在主干,生物量随着胸径的增大明显加大。  相似文献   
64.
? Premise of the study: We isolated and characterized polymorphic microsatellite loci in Cyclobalanopsis glauca (Fagaceae), an evergreen broadleaved monoecious tree, to provide tools for analyzing parentage and mating system. ? Methods and Results: Thirteen polymorphic microsatellite markers were developed and tested in three C. glauca populations. The number of alleles per locus varied from two to 22. The observed and expected heterozygosities within populations were 0.000-0.967 and 0.033-0.949, respectively. ? Conclusions: These polymorphic primers showed high levels of polymorphism within tested populations, and can be used in parentage analysis and mating system estimation of C. glauca.  相似文献   
65.
The ring‐cupped oaks (Quercus subg. Cyclobalanopsis) characterized by united and concentric ring‐cupped acorns, are mainly distributed in broad‐leaved evergreen forests in tropical and subtropical regions of East and Southeast Asia. Their geological history has been traced from the middle Eocene to Pleistocene. Most reports of the subgenus have been on the basis of leaves, whereas the acorns or cupules, more valuable evidence for the inter‐ and intrageneric classifications, have been relatively poorly documented. Here, we describe a new species, Quercus shangcunensis sp. nov., based on a ring‐cupped fossil acorn and pollen on the acorn, as well as Quercus sp. associated leaves, recovered from the early Oligocene Shangcun Formation of Maoming Basin, Guangdong Province, South China. The morphological and anatomical structures of these fossils confirm their attribution to the subg. Cyclobalanopsis. Quercus shangcunensis sp. nov. represents the world's first Oligocene fossil acorn and the earliest fossil acorn in China for the subgenus, indicating that the subg. Cyclobalanopsis arrived in the low latitude area of South China at least by the early Oligocene. Our fossil provides evidence that the subgenus was present in one of its modern distribution centers in the Oligocene, suggesting that the modern distribution patterns of the subg. Cyclobalanopsis most likely originated during or prior to the Oligocene.  相似文献   
66.
青冈常绿阔叶林主要树种叶形基本上都为椭圆形,叶面积在15~40cm2/叶之间,属于中型叶和小型叶;在同一植株上,青冈叶片的大小很好地符合正态分布规律,石栎则近似于负二项分布,甜槠和木荷接近正态分布;主要树种叶的大小是优势种青冈>次优势种石栎>其它伴生种,这在群落结构分化中具有适应意义,即其“生长策略”不同;同一树种叶片大小为中层木叶片>上层木叶片;春夏换叶之前,叶大小和叶重达到第一高峰,秋冬季出现第二峰,叶比重为秋、冬季>春、夏季,这是常绿植物对季节性不利气候(冬季寒冷,夏季高温伏旱)的一种生态适应。  相似文献   
67.
《植物生态学报》1958,44(8):828
研究植物功能性状变异以及不同性状之间的关系, 有助于了解植物对环境的适应策略, 对揭示群落构建和生物多样性维持机制具有重要意义。本研究以桂林岩溶石山青冈群落18种主要木本植物为研究对象, 采用单因素方差分析、混合线性模型以及Pearson相关分析和主成分分析等方法探讨了不同生长型和生活型物种的9个枝、叶功能性状(叶绿素含量、叶片厚度、叶面积、叶干质量、比叶面积、叶干物质含量、叶组织密度、小枝干物质含量和小枝组织密度)的变异与关联。结果表明: (1) 9个功能性状的变异程度不同, 叶面积和叶干质量的种内和种间变异系数最大, 小枝干物质含量和小枝组织密度的种内和种间变异系数最小。(2)在生长型水平上, 乔木、灌木和木质藤本的绝大部分功能性状差异显著。(3)对于不同生活型植物, 除叶面积和比叶面积为落叶植物显著大于常绿植物外, 其余7个功能性状皆为常绿植物显著大于落叶植物。(4)不同生长型和生活型植物功能性状的种内和种间变异大小存在差异, 除部分植物功能性状在一些功能型上表现为种内变异高于种间变异, 其余功能性状的种间变异皆高于种内变异。(5)各功能性状之间关系在个体水平和物种水平大致相同, 但是个体水平上的显著相关比例高于物种水平。研究发现, 植物功能性状的种间变异基本高于种内变异, 但种内变异不容忽略。此外, 不同生长型和生活型物种采取不同的生态策略来适应喀斯特生境。今后的研究应基于个体水平采样并结合环境因子从生长型和生活型等不同功能型角度上深入探究植物功能性状在种内和种间等不同尺度上的变异与关联。  相似文献   
68.
The characters of leaf epidermis (mainly epidermal cells, stomata, trichomes) have been examined in 48 species of Quercus subgen. Cyclobalanopsis of the Fagaceae. The adaxial leaf epidermis was investigated under light microscope. The epidermal cells of this surface are of two types in terms of the outline of their anticlinal wall. One type is characterized by having straight wall, and this type has been observed in most of the species studied, while the other is characterized by having sinuate or sinuolate wall, and this type has been found only in eight species, such as Q. blakei and Q. hui. There exist two types of trichome-bases on this surface: in one type the bases are singlecelled, and this type has been found in most of the species studied, such as Q. oxyodon and Q. augustinii; while in the other the bases consist of a group of cells, and this type has been found only in nine species, such as Q. thorelii and Q. chungii. The abaxial leaf epidermis was investigated under light microscope and scanning electron microscope. The epidermal cells and the trichome-bases on this surface under LM are in morphology essentially similar to those on the adaxial surface. The stomata under LM include three types: cyclocytic, subcyclocytic and anomocytic. The stomatal density is of some diagnostic value to distinguish between closely related species, e.g. the stomatal density in Q. glauca is higher than that in Q. schottkyana. Under SEM the stomata are elliptical or roundish. The most noteworthy feature of the adaxial leaf epidermis is the trichomes. Eight types of trichomes have been observed under SEM: simple-uniseriate, solitary, papillae, stellate, fused-stellate, stipitate-fasciculate, multiradiate and jellyfish-like. The first type, i.e. the simple-uniseriate trichome, is glandular, other six types, i.e. the solitary, papillae, stellate, fused-stellate, stipitate-fasciculate and multiradiate trichomes, are non-glandular, and the last one, i.e. the jellyfish-like trichome, may represent an intermediate type in structure between the glandular and the non-glandular trichomes. Papillae are very common in subgen. Cyclobalanopsis although in the Fagaceae they were previously reported only in a few species of Lithocarpus. The jellyfish-like trichome, observed only in Q. sichouensis, is reported in the Fagaceae for the first time. The evolutionary trends of trichomes are discussed. The trichomes seem to evolve toward the direction of increasing complexity in structure. Papillae are considered as the pedomorphism of trichomes. From papillae the solitary trichomes and then the stellate ones have evolved. The complicated trichome types with more arms may be produced from relatively simple ones with fewer arms by means of varions fusion: several stellate trichomes are fused to form the fused-stellate ones by basal fusion, and by the same way the fused-stellate ones to form the stipitate-fasciculate ones; the multiradiate trichomes are formed by the stellate ones, in which the arms emerge in a variety of seemingly random directions from a typically rounded common base. Based on the above results, it is considered that the trichome features are of important significance for a better understanding of the infrageneric division of Quercus and the phylogenetic relationships between this genus and the other genera in the Fagaceae. The very common presence of papillae in Quercus subgen. Cyclobalanopsis and in a few species of Lithocarpus may indicate that subgen. Cyclobalanopsis is a quite natural group on the one hand, and may have close relationship with Lithocarpus on the other hand. The thin-walled, jellyfish-like trichomes found in Q. sichouensis are in structure similar to the “glandular” peltate trichomes in Trigonobalanus, a genus generally regarded as the most primitive in subfam. Quercoideae, indicating that the affinity between subgen. Cyclobalanopsis and Trigonobalanus may becloser than that between subgen. Quercus and Trigonobalanus.  相似文献   
69.
对栎属青冈亚属17个种及炭栎花粉形态进行扫描电镜观察。结果表明:青冈亚属和炭栎花粉均为三拟孔沟,球形至长球形,(15~28.0)μm×(15.0~25.6)μm。花粉外壁纹饰可划分为3种:(1)蠕虫状(包括皱波状)、(2)聚合颗粒状、(3)棒状或小刺状。各纹饰在组间镶嵌分布。棒状及小刺状纹饰为栎属花粉较为原始式样,并为青冈亚属与高山栎组及部分巴东组(sect.Cerris)共有,推测其间具有较其它栎类更为接近的亲缘关系,可能为广义栎属中较为基础的类群,而与栎亚属sect.Quercuss.s.,Lobatae和Protobalanus关系较远。花粉形态对广义栎属系统分类价值仅适用于较高分类阶元。  相似文献   
70.
浙江北部保护区青冈常绿阔叶林物种多样性   总被引:8,自引:0,他引:8  
胡小兵  于明坚 《广西植物》2003,23(5):399-403
在野外调查的基础上 ,对浙江北部地区保护区 (风景区、森林公园 )的青冈常绿阔叶林物种多样性进行了研究 ,并对不同地点的多样性进行比较分析。结果表明 :群落中不同层次的植物物种多样性大小不一样 ,排列顺序为 :下木层 >林木层 >草本层 ,且不同地点样地的多样性在不同层次上也是不同。样地的坡度与林木层的均匀度指数 J、坡向与林木层多样性指数 H有明显相关 ,建议对北坡及坡度较大的区域给予更大的关注。  相似文献   
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