【作者】 聂谷华；

【导师】 向其柏； 廖亮；

【作者基本信息】 南京林业大学 ， 园林植物与观赏园艺， 2007， 博士

【摘要】 毛茛科(Ranunculaceae)毛茛属(Ranunculus)共有2000种，我国有122种，禺毛茛复合体(Ranunculus cantoniensis complex)是其中一群形态相近的复合分类群。具有分布广、进化历史悠久、生境条件复杂多样、种内形态可塑性大、染色体组倍性变化频率高、行有性和无性两种繁殖方式及其分布区常伴随人类的活动而扩张等特点。鉴于该复合体及其近缘种进化历史的悠久性、生长习性上的多样性、倍性上的多倍性以及遗传变异的丰富性等特点。本研究通过禺毛茛起源的分子学和细胞学研究，分析了禺毛茛复合体的组成及其形成机制；对我国8个省市(云南、贵州、四川、重庆、广西、湖南、广东、江西)的禺毛茛复合体及其近缘种在居群水平上进行了植物形态、核型的遗传变异规律分析。研究结果主要包括以下几个方面：1禺毛茛复合体及其近缘种常常分布在有人类活动的区域，特别是新开垦的荒地，它们往往成为最先的占领者。分布地形具有丰富的多样性，综合其分布的丰富多样性，可将其分为4种类型：丘陵山地型(山地及路旁)；平原湿地型(水沟旁水田边)；滨海滩涂型(河滩、水库旁)和农林间隙地草地型(林缘田埂)。在多倍体种中，既有低倍体和高倍体混生的情况，如匍枝毛茛；也有低倍体生活在相对潮湿的环境，而高倍体生活在相对干旱的情况，如扬子毛茛。另外野外观察表明，导致复合体及其近缘种的形态发生变异的外部因素中，除了居群所处的地理位置外，也与同一地理位置下不同的小生境类型密切相关，如长花毛茛、禺毛茛及毛茛中，均发现分布在相对潮湿地方的植株，其叶形一般呈卵圆形或圆形，根粗壮；而随着居群向干旱的地方分布，其叶形有逐渐变狭窄而成长条形，根也逐渐变成细长的趋势。2分子研究结果表明，在禺毛茛的杂交起源中，除卷喙毛茛外，另一个亲本更可能是长花毛茛，而不是茴茴蒜。且长花毛茛是禺毛茛的母本，而卷喙毛茛是父本。3经分子研究及核型分析，结合Tamura M.(1978)Okada(1984 1989)及廖亮(1995)的研究结果，推断禺毛茛复合体由禺毛茛、卷喙毛茛、长花毛茛、茴茴蒜及扬子毛茛组成。其中禺毛茛是经卷喙毛茛的原始型与长花毛茛的进化型杂交而来。成员间可能是通过短m型染色体组作纽带而构成彼此的亲缘关系。且该复合体为一成熟阶段的复合体。4聚类分析结果，由22个形态性状(见第6方面所列)或7个染色体性状(染色体数目、染色体组总长、m型染色体的比例、sm型染色体比例、st型染色体比例、t型染色体比例、核型不对称系数)聚类分析得出的种间关系，与传统的形态分类结果相似，能较好地反映禺毛茛复合体及其近缘种的种间亲缘关系，说明这些性状的选取对复合体的分析是合理而有效的。5禺毛茛复合体及其近缘种居群内：株高、基生叶柄长、基生叶片长、基生叶片宽、基生叶长宽比、基生叶一回裂片宽、基生叶一回裂片深、基生叶二回裂片宽、基生叶二回裂片深、茎生叶裂片长、茎生叶裂片宽、茎生叶长、茎生叶宽、茎生叶长宽比、花瓣长、花瓣宽、花瓣长宽比、萼片长、萼片宽、萼片长宽比、每花心皮数及瘦果扁平度等22个表型性状均存在较大的差异，其中变异幅度最大的，不同的种有不同的表现性状，但大部分都是营养器官及少数繁殖器官的绝对大小；最小的是花瓣长宽比、花萼长宽比、瘦果扁平度。6禺毛茛复合体及其近缘种居群间：受到不同地理环境的影响，不同的地理居群表现出不同的形态表型性状，其中变异系数较大的为各种营养器官及少数繁殖器官的绝对性状；而且对于那些稳定的(花瓣长宽比、花萼长宽比、瘦果扁平度)，有的种类呈现随纬度增大而增加，如禺毛茛、卷喙毛茛；而有的随经度增加而增加的趋势，如茴茴蒜；同时说明了各形态表型性状受地理环境影响改变程度的差异是不同的，也表明复合体种的形态表型性状表现出其很强的环境适应能力。同时，经方差分析可知，不同的种，居群间差异显著表现在不同的性状上。禺毛茛达到居群间差异显著的性状是基生叶柄长，极显著的是花瓣长；卷喙毛茛各表型性状在居群间花瓣长宽比、瘦果扁平度表现出极显著的差异；茴茴蒜在居群间的变异程度表现得比较剧烈，主要反映在株高、基生叶柄长、茎生叶裂片长、茎生叶裂片宽、花瓣宽、花瓣长宽比极显著差异上；扬子毛茛各表型性状在居群间的变异表现得相对稳定，其中只有基生叶一回裂片宽表现出显著的差异。通过复合体居群间形态特征差异的显著性检验，发现种内变异系数大的性状在居群间的差异不一定显著，如茎生叶长、基生叶二回裂片深；而有些性状的变异系数不大，但在居群间却差异显著甚至极显著，如花瓣长宽比、瘦果扁平度，即居群间性状差异是否显著与种内变异系数大小之间没有内在的联系。7对复合体及其近缘种形态表型性状的数据进行主成分分析结果显示：复合体的不同种类，形成表型差异的主要原因各不相同，但又有共同的特点，那就是其主要原因都归属于营养器官或繁殖器官的绝对值。如禺毛茛株高、基生叶一回裂片宽、萼片长；卷喙毛茛的基生叶二回裂片宽、基生叶一回裂片宽、茎生叶宽；长花毛茛的花瓣长、花瓣宽、萼片长、萼片宽；茴茴蒜的株高、基生叶柄长及基生叶二回裂片宽以及扬子的毛茛花瓣长、花瓣宽。8复合体及其近缘种的核型分析结果表明：禺毛茛、卷喙毛茛大体上呈现出随纬度增大，核型不对称系数增大、染色体组总长减小的趋势(染色体减小是一种进化现象)；茴茴蒜呈现出随经度增大，核型不对称系数增大、染色体组总长减小的趋势，与形态学反映的情况基本吻合。结合核型和形态学的分析结果，推测复合体及其近缘种在我国的进化历史过程中，其可能的迁移路线是从我国西南部的云贵高原及横断山脉一带出发，然后按照从西向东也就是经度不断增大以及从南到北即纬度不断增加的两个方向迁移。二倍体和多倍体的不均衡进化导致禺毛茛的核型不对称系数反而明显小于二倍体的卷喙毛茛、长花毛茛或茴茴蒜，这种现象按单一的Levitzky(1931)的理论难以得到一个满意的解释。9通过核型分析，结合形态学、孢粉学上的资料，可知禺毛茛复合体在毛茛属内处于一个较高的进化位置。更多还原

【Abstract】 The Ranunculaceous Genus Ranunculus includes 2000 species, 122 species are distributedin China. Of which Ranunculus cantoniensis complex is a taxon group which morphology aresimilar. And they have the characteristics of wide distribution, long evolution history,complicated habitation, big plasticity in morphology, high frequency of ploidy, vegetative orsexual reproduction and be in presence along with human’s activity.In view of their longevolutionary history, diversity in growth habits, as well as polyploidy, abundant variation andgenetic diversity. Study on formation of Ranunculus cantoniensis complex by fluorescence insitu hybridization (FISH), TmL-F and karyotype was performed, the mechanism of itsformation was analysed; The morphological and karyotyping characters were studied at thepopulation level in R.cantoniensis complex and its allied species from 8 provinces or city inChina. The main research fruits go as follows:ⅠR.cantoniensis complex and its allied species are often distributed in the areacharacterized by man’s activity. Especially in the newly reclaimed badlands, they usuallybecome the first occupant. Their ecological environment types are in diversity and can beclassified into 4 types which are hill grassland type(grass land and roadside), plain meadowtype(streamside, patty field), seashore bottomland type (rivershore, reservoirside) andinterstitial-meadow of farmland and woodland type(forest margin, ridge of field). In thepolyploidy species, both of the case which low ploidy species is mixed with that of highploidy, such as R.repense ,and the case which low ploidy species is distributed in the relativelyhumid environment, while high ploidy one is present in the arid area, such as R.sieboldii,exist.ⅡThe results based on the datum of moleculacy disclosed that another parent is mostpossibly R.silerifolius var.dolicathus but not R.chinensis,except for R.silerifoliusvar.silerifolius,in the interspecific hybrid origin of R.cantoniensis. It also implied thatR.silerifolius var.dolicathus is female parent, while R.silerifolius var.silerifolius is male parentof R. cantoniensis.ⅢThe R. cantoniensis complex is made up of R. cantoniensis, R.silerifolius var.silerifolius,R.silerifolius var.dolicathus, R.chinensis and R.sieboldii. and it is probable that the members inthe complex became related through the genome called "short m-type". It is a complex of beingunder mature phase.ⅣThe results from the cluster analysis by 22 morphological or 7 karyotypic charactersshowed the interspecific relationship among the species in R. cantoniensis complex and its alliedspecies are almostly identical to that of the classically morphological analysis. They can reflect the relationships among the species in R.cantoniensis complex and its allied species in greatdegree, it means that the choice of these characters are reasonable and effective.ⅤIn the population of R.cantoniensis complex and its applied species: biggishdifferences exist in 22 external morphological traits such as length and width of basal leaf,length and width of petal and so on due to affection by genetic differentiation. Of which thebiggest variation range represent in different characters according to different species, thefewest variation range emerge in the ratio of length to width of petal and sepal,as well as thedegree of flat of achene.ⅥAmong the populations of R.cantoniensis complex and its applied species:Differentgeographical population have different morphological characters resulted from affection bydifferent geography environment; Meanwhile, the stable characters i.e. ratio of length to widthof petal, ratio of length to width of sepal and degree of flat of achene are increasing with theincrease of latitude in some species, while they are increasing with the increase of longitude inother species; it showed that the degree of morphological variation due to affection by differentgeography environment is different and the complex posses high adaptation to environment. Inaddition, whether the difference among populations is considerable or not is not internallyconnect with the variance index in a species.ⅦThe results from the main components analysis on datum of morphologicalcharacters in R.cantoniensis complex indicated that different species in the complex hasdifferent main elements which result of the morphological variation, but the main elementsshare the common characteristics:they all belong to vegetative apparatus or absolute value ofreproductive apparatus such as the width of the first and second turn split of basal leaf, thewidth of stem leaf in R.silerifolius var.silerifolius; length or width of petal and length or widthof sepal in R.silerifolius var.dolicathus; tall, length of leafstalk of basal leaf and the width ofsecond turn split of basal leaf in R. chinensis and length or width of petal in R.sieboldii.ⅧThe analysis based on karyotype showed that the index of karyotype asymmetryincreased、and the total genome length decreased along with the increase of latitude inR.cantoniensis and R.silerifolius var. silerifolius; while they do so along with the increase oflongitude in R.chinensis.The results are almost consistent with those concluded frommorphology data set.Combining them, we can speculate the possible evolution route ofR.cantoniensis complex and its allied species in China is from YunGui altiplano and HengduanMountains to Eastward and Northward area according to the increase of longitude andlatitude, respectively.ⅨThe R. cantoniensis complex is an advanced taxon in the Genus Ranunculus.更多还原