【作者】 陈雪鹃；

【导师】 张启翔；

【作者基本信息】 北京林业大学 ， 园林植物与观赏园艺， 2014， 博士

【摘要】 地被菊作为近年来培育的新型开花地被植物,因其植株紧凑、低矮、花量大、抗性强等优势在园林应用中具有巨大潜力和前景。但现有地被菊品种巾早花品种较少；且部分品种的抗旱性较差。因此,为了培育早花和抗早性优良的地被菊新品种,本研究对菊花野生种质资源进行野外调查、收集和整理,建立菊花野生种质资源圃和地被菊品种资源圃。在对种质资源进行遗传多样性研究的基础上,以早花和优良抗旱性为主要育种目标,兼顾株型低矮、叶色奇特以及香花,开展了地被菊杂交育种研究,对杂交后代主要观赏性状遗传特点进行了分析。同时,利用野生种质资源和地被菊品种进行远缘杂交研究,对远缘杂交亲和性进行分析,通过胚拯救,获取远缘杂交后代,并对其杂种真实性进行了鉴定。构建花期分离广泛的F1杂交群体,选取极端个体,借助混合分群分析法,筛选了地被菊品种花期相关的AFLP分子标记。主要研究结论如下：1.在内蒙古、云南、四川和贵州四省的8个区域内进行菊花野生种质资源调查,以早花和优良抗旱性为目标性状,采集了7个菊属及其近缘属的野生种,结合对已有野生种质资源和地被菊品种资源的整理,建立野生种质资源圃,内有野生种22个,包括不同地理来源的材料共28份；建立地被菊品种资源圃,内有地被菊品种(或育种材料)62个。筛选出6个早花地被菊品种和17个抗旱性优良的野生种。2.建立并优化了AFLP反应体系,筛选出19个多态性丰富的引物对,对12份菊属及其近缘属野生种质资源以及62份地被菊品种资源进行AFLP遗传多样性分析。74份种质材料的遗传相似性系数变异范围为0.564～0.891,共得到452个多态性位点,平均每对引物得到23.8个多态性位点,表明在菊花种质资源中存在丰富的遗传多样性。聚类分析结果表明：野生种在遗传相似性系数0.66处可分为两大类,其聚类结果和供试材料的传统分类学地位以及地理来源高度相关。对所有供试材料进行聚类时,分组结果比较复杂,表现出和材料之间亲缘关系的高度相关性,以及和供试材料瓣型的一定相关性。3.以早花、优良抗旱性为育种目标,进行地被菊品种遗传改良研究。对子代的主要观赏性状遗传特点进行分析,结果表明：花色遗传上,黄色遗传力高于白色；亲本有跳色性状的后代花色变异广泛,但绝大多数表现为跳色性状。花径遗传杂种优势比较明显,尤其品种间杂交,能有效增大花径。株高和冠幅主要介于双亲之间,也有低亲和超亲现象出现。花期遗传特点表现为：秋菊和秋菊杂交,80%左右的后代花期和亲本相近,20%左右的后代表现为晚花。而两个地被菊早花品种杂交,F1花期出现明显分离,其中10.1%的后代表现为比亲本花期提前；8.8%的后代花期比亲本延迟；而大部分后代(81.1%)的花期和亲本接近。优选出了一批株型低矮、花期早、叶片和花序观赏性状突出的优良株系。4.远缘杂交亲和性研究结果表明：地被菊品种之间的杂交亲和性普遍较好；野生种和地被菊品种间杂交：矶菊和毛华菊与地被菊品种亲和性较好,长裂太行菊和甘菊与地被菊品种亲和性较差。野生种与野生种杂交：亲本染色体倍性相同或相近的种杂交亲和性相对较高,当亲本倍性差异较大时,母本倍性低,父本倍性高时结实率较高；母本倍性低而父本倍性高时多表现为不结实或结实少。5.初步建立了菊属植物远缘杂交胚拯救体系,筛选出培养基MS+BA1.5mg·L-1+NAA2.0mg·L-1对三个杂交组合进行幼胚拯救。结果表明：出愈率和成苗率大小主要受杂交亲本的亲缘关系影响,最佳子房培养时期各有不同,从授粉后16d-24d不等。对获得的胚拯救幼苗进行了形态学和AFLP分子鉴定,确定了杂种的真实性。6.以地被菊品种‘米白早’和‘七月桃花’杂交,对获得的F1群体的花期性状进行统计分析,结果表明后代花期分离广泛,呈连续性分布,并出现低亲和超亲现象。在后代中选取极端早花个体和极端晚花个体作为供试群体,采用混合分群分析法,分别取早晚花个体建立子代早花基因池(ZZ)和子代晚花基因池(ZW),利用筛选出的32对AFLP引物对亲本材料和两个基因池进行扩增,初步筛选出与地被菊花期差异相关联的标记E39/M61-156,并用三个地被菊晚花品种进行验证,计算其与控制早花性状的基因的遗传距离为13.43cM,表明该标记应与早花相关,可用于地被菊早花育种的早期辅助选择。更多还原

【Abstract】 Chrysanthemum(Chrysanthemum spp.; Asteraceae, Anthemideae) is not only a traditional Chinese flower but also one of the most important cut flower in the world, which is popular for its exceptionally diverse in flower shape and color. Groud-cover chrysanthemum becomes a new type of flowering ground cover plants in recent years, which has great potential and prospects in urban landscape construction because of its compact and low type, dense flower and strong resistance. However, there are very few early-flowering cultivars existing, and a lot of cultivars’drought-resistance is poor. According to the investigating, collecting and collating of chrysanthemum resources, wild chrysanthemum germplasm nursery and ground-cover chrysanthemum germplasm nursery were established. On the basis of researching of genetic diversity of germplasm resources, hybridization and genetic improvement were processed to breed some new cultivars with early florescence and strong drought-resistance. The genetic rules of major ornamental characteristics of hybrids were analyzed. Distant crossing between wild germplasm resource and ground-cover chrysanthemum cultivars were processed to detect the cross compability. Embryo rescue was adopted to get distant hybridization, which authenticity was identified too. A F1population with wide range of florescence separation was constructed. Based on the selection of extreme individuals, bulked segregation analysis and AFLP molecular markers were employed to screen florescence-related molecular markers. The main conclusions are described as follows:1. Wild chrysanthemum germplasm resources of eight areas in Inner Mongolia, Yunnan, Sichuan and Guizhou provinces were investigated and seven wild specieces were collected for the aim of early-flowering and strong resistance. Combining the collection and collation of species and cultivars, wild chrysanthemum germplasm nursery and ground-cover chrysanthemum germplasm nursery were established, including22wild species and62cultivars. We selected6ground-cover chrysanthemum cultivars with early-florescnce and17species with strong resistance.2. AFLP markers were used to detect the relationships among12wild accessions and62ground-cover chrysanthemum cultivars. Nineteen EcoR/Msel primer combinations revealed452informative polymorphic bands, with a mean of23.8bands per primer-pair. Jaccard’s coefficient of similarity varied from0.64to0.89, indicating much genetic variation in chrysanthemums. The74accessions were classified into two major groups by UPGMA. The dendrogram showed that AFLP variability was closely correlated with both geographic distribution and traditional classification of the wild accessions. Among all accessions, genetic relationship was the most relevant factor in AFLP-marker clustering, while petal type was also informative.3. Hybridization and genetic improvement were processed to breed some new cultivars with early florescence and strong resistance. The genetic rules of major ornamental characteristics of hybrids were analyzed. The results indicated that:yellow flower had much more heredity than white flower. Most hybrids of jump-colored parents were jump-colored too, but had a wide range of variation in flower color. The genetic heterosis of flower diameter was obvious, especially in intervarietal hybridization, which could effectively increase flower diameter. Height and crown of hybrids were mainly between their parents, but also had transgressive segregation. When the parents’florescences were later than September,80%of the offspring’s florescences were similar to their parents and the left20%of the offspring showed late flowering. The hybrids of two early-flowering cultivars showed wide separation in florescence, in which10.1%of which performanced earlier flowering than parents and8.8%of the offspring’s florescence were later than parents, while81.1%of the offspring’s florescences were between parents. A group of hybrids with early-florescence and prominent ornamental traits were seleceted.4. The results of distant hybridization showed that:compatibility between cultivars was generally good. Ajania pacifica and Chrysanthemum vestitum showed much better compatibility than other wild specieces when hybrided with ground-cover cultivars. On the contrary, Opisthopappus longilobus and Chrysanthemum lavandulifolium showed poor compatibility. Compatibility of interspecific hybridization was related to the ploidy. Parents with similar ploidy showed higher affinity than those with different ploidy. When the parents’ploidies were obviously different, female parent with lower ploidy than male parent showed higher ripening rate than the opposite.5. Embryo rescue system was initially established to get distant hybridization. MS medium supplemented with BA1.5mg·L-1and NAA2.0mg·L-1was the optimal medium for germination and growth. The results showed that:callus rate and plant survival rate were mainly affected by the genetic relationship of hybrid parents. The best time for embryo rescue was16-24days after pollination. AFLP and morphological analysis proved the reliability of the hybrids.6. According to the statistical analysis of florescence heredity of F1individuals, which were hybrids of two early-flowering groud-cover cultivars:’Mibaizao’ and ’Qiyuetaohua’, the results showed that the florescence heredity of F1hybrids was continual and widely separated. Transgressive segregation phenomenon was existed. Based on the selection of extreme individuals, early-florescence (ZZ) and late-florescence (ZW) gene pool were established. Thirty-two AFLP primer combinations were used to amplify hybrid parents, ZZ and ZW gene pool. The result of screening and verification indicated that the molecular marker E39/M61-156should be related to early flowering, and the distance between the marker and the gene was13.43cM. The result indicated that this marker could be used for molecular marker-assisted selection of chrysanthemum.更多还原