【作者】 尹载皓；

【导师】 李绍华； 张爱民；

【作者基本信息】 中国农业大学 ， 果树学， 2005， 博士

【摘要】 桃[Prunus persica(L.)Batsch]是起源于中国的重要核果类果树。通过长期的栽培和品种演化,形成极其丰富的种质资源和品种类型。研究桃品种间亲缘关系,分析桃品种的分子演化,对于桃品种改良具有重要意义。本研究利用简单重复序列(Simple sequence sepeat,SSR)技术和内转录间隔(Internal transcribed spacer,ITS)区比较技术对桃的不同品种进行了遗传关系的分析。 本研究所用材料包括来源于中国、日本、美国、韩国的95个桃品种和新疆桃(P.ferganensis Kost.et Riab.),山桃(P.davidiana Franch)和梅(P.mume Sieb.et Zucc.)等3个近缘种。SSR引物是根据已公开发表的108个SSR标记合成,ITS引物据White等人(1990)合成。 通过对108个SSR引物的分析,33个SSR引物具有多态性。用其对96个桃品种进行多态性分析,共获得283个等位基因,每个位点的平均为8.6等位基因。PIC值位于0.40(BPPCT041)至0.98(BPPCT009)之间,平均值为0.80。 基于Nei的遗传距离通过聚类分析将96个桃品种分成6个组。除了少数中国品种之外,绝大多数都和地理起源相吻合。组Ⅰ主要包含了中国的华北和西北的地方品种,并可进一步划分为中国黄肉和中国白肉两个亚组;组Ⅱ为中国南方地方品种及日美品种组,包含的品种占供试品种总数的67%,并进一步划分成四个亚组,日本白桃亚组、中国蟠桃亚组、美国黄桃亚组,还有中国地方观赏桃亚组;组Ⅲ由人面桃和新疆桃组成,组Ⅳ为寿星桃品种和日本育成品种,组Ⅴ为中国的古老地方品种粉寿星;组Ⅵ仅有一个成员即:“白山碧桃”。 进一步分析表明,中国北方的蟠桃和北方地方品种桃的亲缘关系较近,而中国南方蟠桃和日本白桃具有较近的亲源关系。白山碧桃为与其它桃品种遗传距离均很远的观赏桃品种。中国桃的地方品种的遗传背景较日本桃、美国桃和韩国桃品种具有更广泛的遗传变异,进一步表明桃起源于中国。 分析了来源于中国、美国、日本和韩国的52个桃品种的ITS区域的核苷酸序列,并将这52个桃品种与新疆桃、山桃和梅3个近缘种进行了比较,它们的ITS序列长度为624～629 bp,彼此之间并没有多大差别。ITS 1区域碱基序列为229～232 bp,5.8s rDNA基因序列为85bp,ITS 2区域碱基序列为278～281 bp。含2个差异位点的5.8s rDNA基因序列在各品种间不具有多样性,ITS 1和ITS 2区域分别包含21和20个差异位点。 根据系统分类分析结果将这52个桃品种和3个近缘种分为四个分支。分支Ⅰ为“白山碧桃和争、 中国农业大学博士学位论文摘要甲甲熙哪...叫娜.....亘.美国黄桃”分支,由除了一个中国黄桃品种以外的全部黄桃品种,两个中国观赏桃品种和6个中国白桃品种组成;分支n包括日本黄桃的突变种‘JanghowenhwanghO’;分支川主要包括日本白桃,与其它分支具有较大的遗传距离;分支IV为“山桃和中国地方桃品种”分支,可以分为两个亚分支.第一亚分支包括两个中国西北地方品种,第二亚分支包括主要的蟠桃品种和中国北方地方品种,山桃与该分支亲缘关系比较接近.通过对近缘种的比较表明,梅的遗传背景和桃有很大的不同。分析还表明山桃与该52个桃品种的亲缘关系比梅更近,并且与五月鲜和白芒蟠桃等几个中国地方品种处于进化系统树的同一个分支上,山桃很可能是栽培桃的古老祖先之一。另外和处于进化系统树的同一个分支上的中国地方品种可能是比其他地方品种更古老的类型,其中五月鲜和白芒蟠桃可能是本研究中最古老的品种。 SSR和rrs结果还证实了白山碧桃是山桃和桃的杂交种的推论。结合聚类分析结果讨论了新疆桃的分类地位问题,新疆桃可能是桃的一个变种。关键词桃(Pr uno persica L.Batsch),简单重复序列(s SR),内转录间隔区(I Ts),遗传 关系分析常心更多还原

【Abstract】 Peach [Prunus persica (L.) Batsch] was originated in China, along with the several thousands years of cultivation and genetic improvement, there are plentiful of genetic resources and ecological types as well as divergent cultivars in China. The research on genetic relationships of cultivars and molecular evolution of peach will be much helpful to genetic improvement of peach. The phylogenetic relationship of peach and nectarine cultivars was analyzed in this study through the use of SSR markers and ITS sequence.The genetic relationships of 95 peach and nectarine cultivars and three kindred species, P. ferganensis Kost. et Riab, P. davidiana Franch and P. mume Sieb. et Zucc, which originated from China, Japan, the USA and South Korea, were evaluated using 33 simple sequence sepeat markers (SSRs) screened among 108 SSR markers obtained from published SSR markers developed in peach or sweet cherry. 33 SSRs detected polymorphisms among 96 peach and nectarine cultivars and revealed total 283 alleles with an average of 8.6 alleles per locus. The polymorphism information content (PIC) value ranged from 0.40 (BPPCT041) to 0.98 (BPPCT009), with an average of 0.80.Most peaches and nectarines were classified according to their geographical origins except some Chinese cultivars. The 96 peach and nectarine cultivars were classified into 6 groups, "Chinese Northern and Northwestern local cultivars", "Chinese southern local and Japanese & American cultivars", "P. ferganensis and Renmiantao", "Chinese dwarf cultivars", ’Fenshouxing’ and ’Baishanbitao’, respectively, by the cluster analysis based on Nei’s genetic distances:Group I, "Chinese Northern and northwestern local cultivars" was consisted of Chinese northern and northwestern local cultivars, and was divided into two subgroups: Chinese local white peach and yellow peaches;Group II, "Chinese southern local and Japanese & American cultivars" was consisted of around 67 % of all cultivars investigated and was divided into four subgroups: Japanese white peach cultivars, Chinese flat peach cultivars, the American yellow cultivars and some of Chinese local ornamental peach cultivars.Group III, IV and V were "P. ferganensis and Renmiantao", "Chinese dwarf cultivars" and ’Fenshouxing’ were comprised of Chinese local ancient cultivars.Group VI had only ’Baishanbitao’.Based on the clustering results, northern china local flat peaches were closer to northern white cultivars in genetics, while Chinese southern flat peach and Japanese white peach cultivar had a close genetic relationship. ’Baishanbitao’ had been proven an ornamental cultivar as its long distance fromother cultivars in terms of genetic distance. On the whole, the genetic background among Chinese local peach cultivars accounted for much more distribution than those genetic background ranges of the cultivars of Japan, the USA and South Korea, which further proves the P. persica is native to China.Nucleotide sequences of the ITS (internal transcribed spacer) regions were determined for 52 peach cultivars (P. persica L. Batsch) from China, Japan, America and Korea, compared with three related species, P. ferganensis, P. davidiana and P. mume. The ITS regions of 52 peach cultivars, from 624 bp to 629 bp, did not show much of differences. ITS 1 region was 229-232 bp, 5.8s rDNA gene was 85 bp, and ITS 2 is 278-281 bp. 5.8s rDNA genes did not have diversity among cultivars (2 sites), ITS 1 and ITS 2 regions had 21 sites and 20 sites, respectively.Based on the phylogenetic analysis, 52 peach cultivars and two related species (P. ferganensis, P. davidiana) tested in this study were divided into 4 branchs:Branch Ⅰ, "Baishanbitao and American yellow peaches", contained all yellow peaches except 1 Chinese local yellow one, 2 Chinese ornamental cultivars and 6 Chinese white peaches.Branch Ⅱ, Japanese yellow peach mutation, Janghowenhwangdo obtained in Korea.Branch Ⅲ, "Japanese white peaches", had mainly all Japanese white peach cultivars with a bigger difference of genetic distance than that of the other 3 branchs.Branch Ⅳ, "P. david更多还原