【作者】 王明明；

【导师】 王建华；

【作者基本信息】 山东农业大学 ， 作物栽培学与耕作学， 2009， 硕士

【摘要】 木瓜属(Chaenomeles Lindley)隶属蔷薇科(Rosaceae)苹果亚科(Maloideae),约有4个原生种。除日本木瓜(C. japonica (Thunb.) Lindley ex Spach.)特产日本外,皱皮木瓜(C. speciosa (Sweet) Nakai)、毛叶木瓜(C. cathayensis (Hemsl.) Schneider)和西藏木瓜(C. thibetica Yü)主要分布于我国西南部和中东部。本属植物早春花繁色艳,秋天果实芳香,是重要的观赏花木、药材和果品,世界各地广泛栽培。木瓜属植物表型具有很强的可塑性,种间杂交容易,虽然对园艺利用有很高的价值,但对种质资源的鉴别和分类带来很大麻烦。随着新品种的培育和变异类型的调查发现,出现同物异名、同名异物,品种种源和品种间的亲缘关系模糊不清,缺乏完善的品种分类系统等一系列问题,亟待对木瓜属植物品种进行进一步的分类研究。在木瓜属品种资源调查的基础上,选用41个形态学性状对29个栽培品种和2个野生种进行了数量分类学的聚类分析。聚类结果显示,木瓜属品种资源可按品种的来源划分为毛叶木瓜种系、西藏木瓜、皱皮木瓜种系和日本木瓜种系4个表征群。日本木瓜种系较为独立,与毛叶木瓜种系的亲缘关系最远;西藏木瓜与毛叶木瓜的亲缘关系密切;皱皮木瓜种系位于日本木瓜种系和毛叶木瓜种系之间,与C.×superba和C.×vilmoriniana聚在一起。主成分分析表明,41个性状可综合为6个主成分,其累积贡献率达72.396%。综合聚类分析和主成分分析的结果结合实际应用,作者认为木瓜属栽培品种的分类体系首先应以种系(品种来源)为第一级标准,花的大小可作为品种分类的二级标准,花色作第三级分类标准。采用简化的SDS方法从木瓜属植物干燥的幼叶中提取总DNA,并对影响SRAP扩增反应的Mg2+浓度和DNA浓度等反应参数进行优化。优化得到结果稳定、重复性好的SRAP反应体系(25μL):1×PCR Buffer,2.0mmol·L-1 Mg2+,0.2 mmol·L-1 dNTPs,1.0 U Taq酶,10 pmol(各)引物,50 ng模板DNA。本研究建立的反应体系适合木瓜属植物的SRAP研究,为从分子水平鉴定种质资源和构建遗传图谱奠定基础。利用22个SRAP(sequence-related amplified polymorphism)引物组合对27份栽培品种和5份野生种进行聚类分析、主坐标分析及遗传多样性的评价。总共检测到152个多态性位点,平均每个引物组合6.91个的多态性位点,多态性位点百分数为73.08%。聚类分析显示,32份材料可划分为毛叶木瓜种系、西藏木瓜、皱皮木瓜种系、日本木瓜种系4个类群。西藏木瓜与毛叶木瓜种系聚为一支,亲缘关系密切;日本木瓜种系和皱皮木瓜种系聚为另一支,日本木瓜种系与毛叶木瓜种系亲缘关系最远,皱皮木瓜种系位于日本木瓜种系与毛叶木瓜种系之间。遗传多样性分析显示,日本木瓜种系和皱皮木瓜的遗传多样性指数高于毛叶木瓜种系,可能与交配、繁殖方式有关。属的水平上,种系间的遗传分化系数GST=0.4969。SRAP分子标记是研究木瓜属栽培品种遗传关系的有效工具。结合形态特征和SRAP分析结果,花柱基部被毛的状态是鉴定木瓜属栽培品种种源的准确指标之一。C.×superba是非独立的分类群,可作为皱皮木瓜种下的品种群。更多还原

【Abstract】 The genus Chaenomeles Lindley is assigned to the subfamily of the ecologicaily and economically important Rosaceae. Four species, C. cathayensis (Hemsl.) Schneider, C. thibetica Yü, C. speciosa (Sweet) Nakai, and C. japonica (Thunb.) Lindley ex Spach. are now recognized in Chaenomeles. C. japonica is native only in Japan, C. cathayensis, C. thibetica, and C. speciosa are mainly distributed in south-western, middle and eastern of China. The showy flowers of Chaenomeles occur in clusters, and open in the early spring. Fruits become fragrant during ripening in autumn. Chaenomeles species are the important ornamental flowers, herbs and fruits, which are cultivated widely throughout the world. Individual species exhibit a strong plasticity of form and easy interspecific hybridization which is value in commercial horticulture but of difficulty to botanists. With the new cultivars bred and types of variation investigated, there occur synonyms and homonym phenomena. The botanical source and relationship of Chaenomeles cultivars are unclear and the lack of proper cultivar classification needs further taxonomic research.Based on the survey of Chaenomeles cultivars resources, the numerical taxonomic method was used for the cluster analysis of 29 cultivars and 2 wild species with 41 morphological characters. The result revealed that 31 OTUs (Operational Taxonomic Units) could be divided into 4 phenetic groups according to their botanical sources, namely C. cathayensis system, C. thibetica, C. speciosa system and C. japonica system. C. japonica system and C. cathayensis system are the most distantly related systems; C. thibetica appeared to be rather closely related to C. cathayensis; C. speciosa system together with the hybrid taxon C.×superba and C.×vilmoriniana takes an intermediate position between C. japonica system and C. cathayensis system. Principal component analysis showed that the 41 characters can be consolidated for the 6 principal components and their accumulative contribution ratio amounted to 72.396%. Integrated cluster analysis and principal component analysis with practical applications , the author suggested that the classification of Chaenomeles cultivars should be firstly based on the systematics of wild species (cultivar sources). Then, the flower size could be as the second criterion for the classification of Chaenomeles cultivars, and the flower color as the third criterion.The purpose of this paper is intended to establish SRAP reaction system in Chaenomeles species. Simplified SDS method was used to extract the genomic DNA from the silica gel dried young leaves. The factors which affect the SRAP amplification, such as Mg2+ concentration and template DNAs concentration, were optimized. Efficient SRAP reaction systems were developed as follows: the reactions were performed in a volume of 25μL containing 1×PCR Buffer, 2.0 mmol·L-1 Mg2+, 0.2 mmol·L-1 dNTPs, 1.0 U Taq DNA polymerase, 10 pmol primers, and 50 ng template DNAs. Using the optimum system, 22 pairs of SRAP primers, with high stability and polymorphism had been obtained. The reaction system in this study is suitable for SRAP research of Chaenomeles species, and it has set up a foundation for species germplasm identification and genetic map construction.The botanical source, genetic relationship, and genetic diversity of Chaenomeles cultivars were probed. The arm is to provide a scientific basis for Chaenomeles cultivars classification. The cluster analysis, principal coordinate analysis and genetic diversity of 27 cultivars of Chaenomeles and 5 wild species were analyzed using 22 SRAP primer combinations. A total of 152 polymorphic loci were detected among these materials with average 6.91 polymorphic loci per SRAP primer combinations, and the percentage of polymorphic loci was 73.08%. The cluster analysis result revealed 32 materials could be divided into 4 groups, namely C. cathayensis system, C. thibetica, C. speciosa system and C. japonica system. C. thibetica appeared to be rather closely related to C. cathayensis system. C. japonica system and C. speciosa system clustered into together. C. japonica system and C. cathayensis system were the most distantly related systems. C. speciosa system took an intermediate position between C. japonica system and C. cathayensis system. Genetic diversity analysis showed that C. japonica system and C. speciosa system were more diverse than C. cathayensis system. Differences in mating and breeding systems among the species can be suggested as a possible explanation of the results. In the genus level, the coefficient of genetic differentiation among species (GST) was 0.4969. SRAP molecular markers were an effective research tool for genetic relationship of Chaenomeles cultivars. Integrated morphological characters and SRAP analysis, the state of style hairiness basally was one of accurate indicators which identified the botanical source of Chaenomeles cultivars. C.×superba was a non-independent taxon, and could be used as a cultivar group in C. speciosa.更多还原