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

(1)利用细胞器DNA的matK序列数据对蔷薇属32种植物进行了系统发育分析，结果表明，蔷薇属植物的分子分类与传统分类基本一致，但仍存在一些异常现象，如Pimpinellifoliae组的多系性等。由于对现代玫瑰有贡献的6个原始种仅属于一个分支，现代玫瑰的遗传背景似乎是狭窄的。(2)利用核DNA的ITS序列对蔷薇属23种植物进行了系统发育分析，其分子分类结果与matK序列分析结果一致。Platyrhodon亚属和Hulthemia亚属在四个亚属内形成一个分支。(3)利用S等位基因特异PCR技术对46个苹果品种和苹果属植物的S等位基因进行了基因型鉴定。这一分析结果对确定苹果属内的亲缘关系有一定的参考价值。(4)‘津轻’、‘赤木’和‘优口’似乎分别是利用具有S_7-、S_7-和S_9-等位基因的花粉亲本产生的。结果表明，至少有三个未克隆的S等位基因。'Kinsei'和'Kizashi'的S基因型与其亲本的预期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。在‘美国夏梨’、‘Indo’、‘北之町’、‘静香’、‘陆津’和‘Meku 10’中发现了一个新的S等位基因S_g。(5)在推导的氨基酸水平上，Sg与SS f的同源性高达94%。HV区之间只有两个氨基酸的差异，这是SS_g和SS_f的S等位基因特异性的原因。

(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.