中华猕猴桃和美昧猕猴桃的倍性变异及地理分布研究

根据已有的猕猴桃自然地理分布资料,通过对中华猕猴桃（Actinidia chinensis）和美味猕猴桃（A．deliciosa）野外分布居群的详细调查,利用流式细胞技术对我国西部高原台地向中东部丘陵平原过渡地带6个纯中华猕猴桃、1个纯美味猕猴桃和5个中华／美味猕猴桃同域分布居群共276个个体的倍性进行了检测。结果表明：（1）中华猕猴桃存在二倍体和四倍体,美味猕猴桃存在四倍体、五倍体和六倍体;（2）中华猕猴桃和美昧猕猴桃在经度和纬度的分布上存在显著差异（P〈0．05）,中华猕猴桃在经度上偏东分布而美味猕猴桃偏西,纬度分布上中华猕猴桃偏南而美味猕猴桃偏北;而且不同倍性小种在经、纬度分布上呈现显著差异（P〈0．05）,二倍体、四倍体、六倍体的分布在经度上依次从东到西、纬度上从南到北;（3）中华猕猴桃和美味猕猴桃不同倍性小种的海拔分布存在显著性差异（P〈0．05）,二倍体小种分布海拔最低,四倍体小种次之,六倍体小种海拔分布最高,但通过LSD分析四倍体个体和六倍体个体在海拔分布上不存在显著差异（P〉0．05）。通过对中华／美味猕猴桃这两种具有重要经济价值的果树的倍性变异及地理分布的探讨,提出了猕猴桃倍性小种分布的上述规律并给猕猴桃种质资源收集、评价、创新和可持续利用方面提供了初步的研究基础,尤其是为我国猕猴桃新品种选育提供了基础数据和科学依据。     

中华猕猴桃和美味猕猴桃的倍性变异及地理分布研究

根据已有的猕猴桃自然地理分布资料,通过对中华猕猴桃（Actinidia chinensis）和美味猕猴桃（A．deliciosa）野外分布居群的详细调查,利用流式细胞技术对我国西部高原台地向中东部丘陵平原过渡地带6个纯中华猕猴桃、1个纯美味猕猴桃和5个中华／美味猕猴桃同域分布居群共276个个体的倍性进行了检测。结果表明：（1）中华猕猴桃存在二倍体和四倍体,美味猕猴桃存在四倍体、五倍体和六倍体;（2）中华猕猴桃和美昧猕猴桃在经度和纬度的分布上存在显著差异（P〈0．05）,中华猕猴桃在经度上偏东分布而美味猕猴桃偏西,纬度分布上中华猕猴桃偏南而美味猕猴桃偏北;而且不同倍性小种在经、纬度分布上呈现显著差异（P〈0．05）,二倍体、四倍体、六倍体的分布在经度上依次从东到西、纬度上从南到北;（3）中华猕猴桃和美味猕猴桃不同倍性小种的海拔分布存在显著性差异（P〈0．05）,二倍体小种分布海拔最低,四倍体小种次之,六倍体小种海拔分布最高,但通过LSD分析四倍体个体和六倍体个体在海拔分布上不存在显著差异（P〉0．05）。通过对中华／美味猕猴桃这两种具有重要经济价值的果树的倍性变异及地理分布的探讨,提出了猕猴桃倍性小种分布的上述规律并给猕猴桃种质资源收集、评价、创新和可持续利用方面提供了初步的研究基础,尤其是为我国猕猴桃新品种选育提供了基础数据和科学依据。     

猕猴桃野生居群的SSR分析初报

采用SSR分子标记技术对我国猕猴桃的2个商业栽培物种——中华猕猴桃和美味猕猴桃的9个天然居群(共221个样)的遗传多样性进行了初步分析。通过对14对猕猴桃引物的筛选,8对重现性好的引物扩增结果表现出良好的多态性。在8个多态性位点上共获得222个等位基因。居群等位基因平均数A=17．3,多态位点百分率P-100,多态信息指数PIC为0．87～0．96,显示出我国的猕猴桃野生居群具有极高的遗传多样性。中华猕猴桃和美味猕猴桃野生居群拥有高比例的共同等位基因,反映出二者的亲缘关系极近。     

6种1变种猕猴桃植物染色体数目的研究

报道了猕猴桃属６种１变种细胞染色体数目,表明湖北猕猴桃、激光猕猴桃、黄毛猕猴桃为二倍体,２ｎ＝２ｘ＝５８;大花猕猴桃为四倍体,２ｎ＝４ｘ－１１６,绿果猕猴桃（美味猕猴桃的１个变种）为种倍体,染色体数目２ｎ＝４ｘ－１１６,以上均为首次报道。并再次证实ｘ＝２９应是本属染色体数目的基础,狗枣猕猴桃和阔叶猕猴桃二倍体类型２＝５８。     

中华猕猴桃和美味猕猴桃自然居群遗传结构及其种间杂交渐渗

 利用9对SSR引物对中华猕猴桃（Actinidia chinensis）和美味猕猴桃（A. deliciosa）两近缘种的5个同域分布复合体和各自1个非同域分布居群进行了遗传多样性、居群遗传结构的分析以及种间杂交渐渗的探讨。结果表明：1）两物种共有等位基因比例高达81.13%,物种特有等位基因较少（中华猕猴桃：13.27%,美味猕猴桃：5.61%）,但共享等位基因表型频率在两近缘种间存在差异,而且与各同域复合体中两物种样本的交错程度或间距存在关联;2）两种猕猴桃均具有极高遗传多样性,美味猕猴桃的遗传多样性（H_o＝0 .749, PIC＝0.818）都略高于中华猕猴桃（H_o＝0.686,PIC＝0.799）;3）两猕 猴桃物种均具有较低的Nei’s居群遗传分化度,但AMOVA分析结果揭示种内异域居群间（F_ST=0.091 5）和同域复合体种间（F_ST=0.111 5）均存在一定程度的遗传分化;中华猕猴桃居群遗传分化（G_ST=0.086; F_ST=0.212 1）高于美味猕猴桃（G_ST= 0.080;F_ST=0.142 0）;4）同域分布复合体两物种间的遗传分化（G_ST=0.020）低于物种内异域居群间的遗传分化（中华猕猴桃：G_ST=0.086; 美味猕猴桃：G_ST=0.080）,同域复合体物种间的基因流（N_m＝7.89 -29.75）远远高于 同种异域居群间（中华猕猴桃：N_m =2.663; 美味猕猴桃：N_m=2.880）; 5）居群UPGMA聚类揭示在同一地域的居群优先聚类,个体聚类结果显示多数个体聚在各自居群组内,但各地理居群并不按地理距离的远近聚类,这与Mantel相关性检测所揭示的居群间遗传距离与地理距离没有显著性相关的结果一致。进一步分析表明两种猕猴桃的遗传多样性和居群遗传结构不仅受其广域分布、远交、晚期分化等生活史特性的影响,同时还与猕猴桃的染色体基数高 (x=29)、倍性复杂和种间杂交等因素密切相关,其中两种猕猴桃的共享祖先多态性和同域分布种间杂交基因渗透对两猕猴桃的居群遗传结构产生了重要影响。     

猕猴桃品种SSR分析的初步研究

通过对16对高多态性的猕猴桃SSR引物筛选,选用了9对稳定、适用性好的引物对我国栽培的48个猕猴桃品种(品系)进行了初步研究,在9个多态性位点上共获得213个等位基因片段,其SSR指纹图谱可将供试品种完全区分开。遗传多样性分析和分辨力检测表明,我国猕猴桃栽培品种具有较高的遗传多样性,SSR标记在猕猴桃品种中有较高鉴定效率。中华／美味品种群拥有高比例的共同等位基因,反应出两者极近的亲缘关系。本研究为进一步建立我国猕猴桃栽培品种的分子指纹鉴定体系奠定了基础,为制定猕猴桃品种资源的有效保育和利用策略提供了科学依据,并对深入研究中华猕猴桃和美味猕猴桃间的系统关系提供了实验数据。     

猕猴桃属种间体细胞杂种

利用PEG融合方法,分别进行了中华猕猴桃(Actinidia chinensis var.chinensis)(2n=2x=58)子叶愈伤组织来源的原生质体与美味猕猴桃(A.deliciosa var.deiciosa)(2n=6x=174)子叶愈伤组织原生质体、以及狗枣猕猴桃(A.kolomikta)(2n=2x=58)叶肉原生质体种间原生质体融合。结果表明:中华猕猴桃与美味猕猴桃融合的1个克隆和中华猕猴桃与狗枣猕猴桃融合的4个克隆的RAPD谱带分别具有双亲特异的DNA谱带;经流式细胞仪分析,前者细胞核倍性推测为8倍体,后者细胞核为3倍体、4倍体和5倍体。初步鉴定这5个克隆是猕猴桃属种间体细胞杂种。     

猕猴桃优良株系果实生长发育规律研究

猕猴桃果实生长发育过程可分为三个时期。(1)迅速增长期:中华猕猴桃大约从4月中旬至6月上旬;美味猕猴桃大约从4月底或5月初至6月中下旬。(2)缓慢增长期:中华猕猴桃约自6月上旬至7月下旬;美味猕猴桃自6月下旬至7月下旬。(3)停滞增长期:中华猕猴桃从7月下旬至8月底或9月初;美味猕猴桃自8月上旬至9月上中旬。 中华猕猴桃优株果实可溶性固形物含量增长过程可分为四个阶段:(1)微升增长阶段,持续时间5周左右;(2)活跃增长阶段,持续2周左右;(3)迅速增长阶段,持续2周左右;(4)渐缓增长阶段。美味猕猴桃优株及绿果猕猴桃果实固形物含量增大变化的阶段性不明显。     

猕猴桃种间及种内杂交亲和性研究

以3个种的9个猕猴桃品种为试材,通过培养法比较它们的花粉活力,用荧光显微镜观察猕猴桃种间与种内杂交亲和性,并统计其亲和指数及坐果率,为猕猴桃的杂交育种以及最佳授粉树的选配提供依据.结果表明:猕猴桃花粉活力在种间表现为美味猕猴桃＞中华猕猴桃＞狗枣猕猴桃;中华猕猴桃和美味猕猴桃种间和种内杂交组合的柱头识别反应快,花粉在柱头粘附多、生长快且萌发率高、亲和性较强且坐果率较高,而用狗枣猕猴桃与中华猕猴桃和美味猕猴桃种间杂交的花粉在柱头上萌发生长发育缓慢,其亲和性弱,平均坐果率仅为19.81%;30个杂交组合中亲和指数最高的是'金阳'×'金阳'雄株,亲和指数为960.33,坐果率为95.56%,最低的是'狗枣'×'金阳'雄株,亲和指数201.60,坐果率为12.22%.研究发现,猕猴桃的种间亲和性小于种内亲和性,同种内不同品种间的亲和性与坐果率也不同.     

猕猴桃属种间嫁接亲和性试验研究及抗根结线虫砧木的初步筛选

以中华猕猴桃（Actinidia chinensis)武植2号（Wuzhi-2),通山5号（Tongshan-5)品种和美味猕猴桃（A.deliciosa)金魁（Jinkui)品种为接穗,采用美味猕猴桃等9种类型猕猴桃一年生实生苗为砧木进行嫁接,研究其短期嫁接亲和性,并对这9种砧木进行抗根结线虫（Meloidogyne)筛选试验。结果表明,种间的嫁接亲和性及抗根线虫性 均有显著差异：以美味猕猴桃和中华猕猴桃优良品种实生苗为砧木,与3个品种均有高的亲和性,成活率高达100％,且抗性在9种砧木中最强;其它物种作砧木均有不足,武植2号／山猴猴桃,通山5号／M16,通山5号／山梨猕猴桃3个嫁接组合的亲和性均较好,成活率在80％以上,但山梨猕猴桃较易感病且与金魁的亲和力较低,M16抗性虽较好,但与金魁,武植2号的亲和力也较低,漓江猕猴桃是抗性较强的物种,但它与3种接穗品种的亲和力都较小,其它5种砧木,对根结线虫的抗性均不强,因此结合成活率及抗根结线虫两因素,在供试材料中,美味猴猕桃和中华猕猴桃接适应性广且抗性强,是较好的砧木或选育砧木的亲本材料。     

Sex determination in Actinidia. 1. Sex-linked markers and progeny sex ratio in diploid A. chinensis

 First results from two strategies aimed at elucidating the genetics of sex in the dioecious genus Actinidia Lindl. (Actinidiaceae) support the hypothesis that sex-determining genes are localized in a pair of chromosomes which, although cytologically indistinguishable, function like an XX/XY system with male heterogamety. A. chinensis Planch., a close relative of the kiwifruit [A. deliciosa (A. Chev.) CF Liang et AR Ferguson], has diploid and tetraploid races. Bulk segregant analysis to find sex-linked markers revealed two markers whose inheritance patterns in three diploid families showed X and Y linkage and indicated that the male is the heterogametic sex. Some recombination between the markers and the sex-determining loci was also demonstrated. Sex ratios in 12 progenies from controlled crosses varied around 1:1, as expected for an XX/XY system. Received: 20 December 1995 / Revision accepted: 24 April 1997     

猕猴桃属植物的cpSSR遗传多样性及其同域分布物种的杂交渐渗与同塑

同域分布的近缘物种常常发生杂交而导致种间基因渐渗, 从而对相关物种的自然居群遗传结构产生重要影响, 近缘种间的杂交渐渗已成为进化生物学和保护生物学关注的热点。本研究采用8对cpSSR引物对我国西部高原台地向中东部丘陵平原过渡地带同域重叠分布的猕猴桃属(Actinidia)7个物种的自然居群遗传多样性、居群遗传结构和同域分布种间遗传分化进行了检测。结果表明: (1)在6个多态性位点检测到18个等位基因形成的42个单倍型, 尽管各单倍型间显示了复杂的网状进化关系, 但还是具有明显的物种特异性; (2)各物种有丰富的cpSSR遗传多样性, 但种间存在较大差异, 绵毛猕猴桃(Actinidia fulvicoma var. lanata)的遗传多样性水平最高(P = 62.50%, h_T = 0.173, H_T = 0.897), 美味猕猴桃(A. deliciosa)的最低(P = 37.5％, h_T = 0.041, H_T = 0.516); (3)尽管不同物种的居群分化程度存在较大差异, 但种内居群间存在明显分化(G_ST为0.319–0.780, F_ST为0.401–0.695), 居群间的基因流不足(N_m为0.219–0.747<1); 其中以美味猕猴桃的居群遗传分化度最高(G_ST = 0.780, F_ST = 0.695); (4)遗传分化系数G_ST(unordered alleles)与N_ST(ordered alleles)无显著差异, 揭示本研究的大多数猕猴桃属物种不存在系统地理结构, 与用Mantel检验得出的居群遗传距离和地理距离不存在显著性相关的结果一致; (5)除了中华/美味猕猴桃复合体(A. chinensis / A. deliciosa complex)的湖北五峰(HW)和广西资源(GZ)两个同域复合居群外, 同域分布的物种间遗传分化强烈(F_ST为0.476–0.990), 与UPGMA聚类时多数居群按各自物种聚类的结果一致。进一步分析表明, 中华/美味猕猴桃复合体近缘种间存在明显的共祖多态性和杂交渐渗现象, 近缘种植株分布的交错程度以及是否存在亚居群结构对杂交渐渗存在着重要影响。亲缘关系较远的物种间杂交渐渗事件稀少, 但存在个别同塑事件。本研究结果有助于进一步了解猕猴桃属植物自然居群cpDNA的遗传特性和渐渗杂交进化模式, 为我国猕猴桃野生种质资源保育及可持续开发利用提供基础数据和科学依据。     

A phylogenetic analysis of the monogenomic Triticeae (Poaceae) based on morphology

A cladistic analysis, primarily based on morphology, is presented from 40 diploid taxa representing the 24 monogenomic genera of the Triticeae. General problems related to the treatment of hybrids and supposedly allopolyploid heterogenomic taxa are highlighted. Special emphasis is given to taxa not traditionally included in Aegilops s.J. Most of the 33 characters used in the analysis are coded as binary. The only four multistate characters in the matrix are treated as unordered. Three diploid species of Bromus are used as outgroup. The number of equally parsimonious trees found is very large (approx. 170000; length = 107, ci = 0.36, ri = 0.75) and the strict consensus tree has an expectedly low level of resolution. However, most of the equally parsimonious trees owe their existence to an unresolved Aegilops clade. If this clade is replaced by its hypothetical ancestor, the number of equally parsimonious trees drops dramatically (48; length = 78, ci = 0.45, ri = 0.76). When trees for which more highly resolved compatible trees exist are excluded, only two trees remain. Bremer support is used as a measure of branch support. The trees based on morphology and on molecular data are largely incongruent.     

Quantitative taxonomic analyses of Actinidia (Actinidiaceae) in China based on micromorphological characters of foliar trichomes

There are various arguments on classification of the genus Actinidia Lindl., a genus with approximately 63 species, 59 of which have been found in China. The paper investigated the characteristics of foliar trichomes of 35 taxa from China under optical microscope, including size, celluar structure, distribution and density. According to their micromorphological characteristics, foliar trichomes can be classified into the following six categories: 1) single-cell hairs; 2) uniseriate hairs, including linear, bulbous, twisted, straight-walled, and bent-walled hairs; 3) multiseriate hairs, including twisted, straight-walled and gradually sharpening, straight-walled and suddenly sharpening, bent-walled and gradually sharpening, and suddenly sharpening hairs; 4) multiseriate thick hairs, including pillar hairs, gradually sharpening thick hairs, and suddenly sharpening thick hairs; 5) stellate hairs, including parenchyma-stellate and sclerenchyma-stellate (normal state and special states such as rosulate, peltate-stellate, and overlopping-stellate) hairs; and 6) dichotomous hairs. On the basis of the micromorphological characteristics of foliar trichomes in Actinidia, with Clematoclethra lasioclada as an outgroup, both the quantitative cladistic analysis and phenetic analysis were performed using Wagner method and UPGMA clustering method respectively to reconstruct the phylogeny of Actinidia in China. The phylogenetic tree generated by cladistic analysis suggests that the sect. Leiocarpae be a monophyletic group, but other three sections, i.e., sect. Maculatae, sect. Strigosae and sect. Stellatae, be non-monophyletic groups. The results obtained from the phenetic analysis reflect relationships among the taxa of Actinidia in China, especially a close relationship between A. chinensis and A. deliciosa, and a relatively remote relationship between A. callosa var. henryi and A. callosa var. discolor. In conclusion, the micromorphological characters of foliar trichomes and the methods of quantitative taxonomic analysis are of key importance tostudies on phylogenetic and phenetic relationships of Actinidia.