Molecular phylogeny of Rosaceae based on S-allele genotype and organelle DNA polymorphism

(1)利用细胞器DNA的matK序列数据对32种蔷薇进行了系统发育分析。分子分类与传统分类基本一致，但存在多聚性等异常。由于形成现代玫瑰的6个原始物种只属于一个分支，因此现代玫瑰的遗传背景似乎很狭窄。(2)利用核DNA ITS序列数据对23个蔷薇属植物进行了系统发育分析。分子分类与matK序列分析结果吻合较好。Platyrhodon亚属和Hulthemia亚属在四个亚属中形成了一个分支。(3)采用s等位基因特异性PCR方法对46个海棠品种和海棠种的s等位基因型进行了鉴定。这一分析有助于确定苹果属内的亲缘关系。(4)‘Tsugaru’、‘Akagi’和‘Youkou’似乎分别是由含有S_7-、S_7-或s_9等位基因的花粉亲本产生的。结果表明，至少存在3个未克隆的s等位基因。“Kinsei”和“Kizashi”的s基因型与其亲本的s基因型不一致，表明它们是具有S_9-或s_3等位基因的花粉亲本的衍生物。一个新的s等位基因S_g被提议存在于‘American Summer Pearmain’、‘Indo’、‘Kitanosachi’、‘Shizuka’、‘Mutsu’和‘Meku 10’中。(5)一个新的S-RNase S_g在推导出的氨基酸水平上与SS_f具有很高的相似性（94%）。SS_g和SS_f的s等位基因特异性在HV区之间仅存在两个氨基酸差异。

(1) Phylogenetic analysis among 32 Rosa species was carried out using the matK sequence data of organelle DNA.The molecular classification conformed closely to the traditional classification with some anomalies such as polyphyly of section Pimpinellifoliae. As six original species that contributed to modern roses were found to belong to only one clade, the genetic background of modem roses seems to be a narrow one.(2) Phylogenetic analysis among 23 Rosa species was carried out using the ITS sequence data of nuclear DNA.The molecular classification was well in agreement with that of matK sequence analysis. Subgenus Platyrhodon and Hulthemia formed a clade within four subgenera.(3) S-allele genotypes of 46 Malus x domestica cultivars and Malus species were identified by S-allele specific PCR analysis. This analysis was useful in determining the genetic relationship within the genus Malus.(4) 'Tsugaru', 'Akagi', and 'Youkou' seem to have been produced by using pollen parents possessing the S_7-, S_7- or S_9-allele, respectively. It was suggested that there were at least three uncloned S-alleles. The S-genotypes of 'Kinsei' and 'Kizashi' were inconsistent with expected S-genotypes of their parents, indicating that they are derivatives from pollen parents having the S_9- or S_3-allele. A new S-allele, S_g, was proposed to be present in 'American Summer Pearmain', 'Indo', 'Kitanosachi', 'Shizuka', Mutsu' and 'Meku 10'.(5) A new S-RNase, S_g, shows a high similarity to SS_f (94%) at the deduced amino acid level. There are only two amino-acid differences between HV regions, which are responsible for the S-allele specificity of SS_g and SS_f.