【作者】 南程慧；

【导师】 汤庚国； 王贤荣；

【作者基本信息】 南京林业大学 ， 植物学， 2012， 博士

【摘要】 迎春樱（Cerasus discoidea Yü et Li）隶属蔷薇科（Rosaceae）樱属（Cerasus），为我国野生观赏樱花资源中一珍贵特有种。目前，除极少部分地区对其野生资源进行不合理的园林利用外，相关研究还未见报道。本文从居群变异、群落生态学、繁殖机理及技术等方面对迎春樱进行了系统的研究。主要结论如下：（1）迎春樱表型基本特征存在不同程度的变异，其中叶部、花部表型变异相对较大；叶部表型数量变异相对不稳定，居群间、居群内变异界限不明显；花部表型数量变异类群间差异明显，支持迎春樱种系下设立大花迎春樱Cerasus discoidea var. grandiflora C. H.Nan, X. R. Wang et G. G. Tang和垂枝迎春樱Cerasus discoidea var. pendula C. H. Nan, X. R.Wang et G. G. Tang的分类处理。（2）迎春樱总DNA提取困难，采用改进的CTAB裂解——硅珠吸附法，通过控制鲜样、干样质量的方法可克服提取过程中上清液难以获得的问题，达到有效提取的目的；通过对19对引物退火温度的探讨，建立了适合迎春樱SSR-PCR扩增的反应体系。（3）物种组成、群落结构、重要值、相似性系数、物种多样性结果表明，迎春樱群落物种组成分散；林相垂直结构差异小，成层现象不明显，灌草更新层所占比例较大；迎春樱在乔木层及灌木层的重要值普遍偏低，多依存在次生林中；不同地区间物种组成相似性水平不高；群落内物种多样性指数均为灌木层＞乔木层，灌木层植物种类相对较多。（4）迎春樱种群生态位宽度、生态位重叠较高，迎春樱具有较强的环境适应性，种间生存环境竞争激烈，迎春樱多被排挤于次生林缘或疏林下；迎春樱种群以根蘖苗无性更新为主，大量根蘖苗的存在使种群年龄结构多为稳定的增长型，有性更新存在障碍，实生苗数量稀少，对其种群发展不利。（5）迎春樱褐色种皮与种胚之间有一环带状结构，通过形态观测、质地、功能的探讨推测其为迎春樱内种皮，对种子起到保护作用。迎春樱种子具有综合休眠特性，是内果皮、种皮的机械障碍引起的物理休眠，ABA等萌发抑制类物质和IAA等促进类物质相互控制引起的生理休眠共同作用的结果；通过去除内果皮、种皮、赤霉素处理、低温沙藏等方法可打破迎春樱种子休眠，促进萌发。低温层积选播法适合迎春樱的穴盘育苗，育苗不受季节限制，种子利用率高；3～5℃恒温层积0～30d＋冬季自然低温播种的方法适合樱属的大田育苗，具有简单易行，培育成本极低的优点。（6）迎春樱组培外植体的选择以种胚及4月份获得的嫩枝茎尖为佳，其中6-BA、GA3均能有效解除迎春樱种子休眠；丛芽诱导试验中，前期高浓度6-BA刺激一段时间后，转入低浓度培养基中可促进丛芽大量产生；含GA3及低浓度琼脂的MS培养基有利于继代壮苗；3/4MS培养基附加NAA可促进迎春樱接种材料生根；材料生根后可直接移栽于同等温度、光照条件下进行炼苗移栽。更多还原

【Abstract】 Cerasus discoidea Yü et Li, belong to genus Cerasus (Rosaceae), is a precious endemicspecies of wild cherry in China. However, the utilization and development of wild plant resourcesof this species was irrational, and current related research had not been reported. In order toprotect it, the population variation, community ecology as well as reproductive technology of thisspecies had been studied in this dissertation.The major work and conclusions were as follows:(1) It was shown there was considerable variances in phenotypic characteristics of Cerasusdiscoidea, the main phenotypic variation was leaves and flowers. The quantitative variation ofleaves was not relatively unstable, and great variabilities within populations or betweenpopulations. The quantitative variation of flowers was obvious between groups, C. discoide var.grandiflora C. H. Nan, X. R. Wang et G. G. Tang and C. discoidea var. pendula C. H. Nan, X. R.Wang et G. G. Tang were supported to be new variety of C. discoidea Yü et Li.(2) It’s very difficult to extract the total genomic DNA of Cerasus discoidea by CTAB. Toobtain the enough supernatant liquid, we improved the method CTAB method (Silica beads assay)by controlling quality of fresh and dry samples. A suitable SSR-PCR amplification system wascreated through selecting one of the best annealing temperature of19primer for C. discoidea.(3) The species composition, community structure, important value, similarity coefficient,species diversity were analyzed. The results showed that the species composition of C. discoideawas dispersion. The vertical structure of forest form existed little differences, and stratificationwas not obvious, the proportion of regeneration layer of shrub and herb was larger. The importantvalue of tree layer and shrub layer was generally lower, and grew in secondary forests. Thesimilarity of species composition was not high between regions. The species diversity indicesshowed shrub layer> tree layer within communities, the plant species of shrub layer were relativelarger.(4)The populations niche breadth and niche overlap of C. discoidea were higher, and hadbetter environmental adaptability; interspecific survival environment competition was fierce, C.discoidea was freezed out in forest margin or under open forest. The population regeneration wasmainly by asexual suckers, the population age structure was stable developing, because of lots ofsuckers. The number of seedlings were scarce, because of obstacles in sexual update, it was badfor population development of C. discoidea.(5)The banded structure between seed coats and embryos of C. discoidea can protect seed. Itwas identified as endotesta by study in morphology, texture and functions. The two main reasonsof dormancy were the mechanical obstacle of seed coats and germination inhibitor of ABA inseeds. It was advantagous to break dormancy by removing seed coat, gibberellin treatment or lowtemperature stratification. Just cold stratification was suitable for plug seedling and no limits of season changes. After cold stratification(3-5℃)0-30days and then sowing in winter was suitablefor field seedling.(6)The results showed that seed embryo and tender bud were the best appropriate explant fortissue culture. The buds induction could be stimulated with low concentration medium after highconcentration6-BA and the shoots grew stongly on GA3and low concentration agar. The3/4MSculture medium with NAA was suitalbe for the root differentiation. The tissue culture seedlingcan directly transplanted with same tempeture and light condition training,the survival rate was93.8%.更多还原