含笑属叶绿体基因组限制位点变异性研究

采用不连续蔗糖梯度离心法分别提取白兰(Michelia alba DC.)和含笑(Michelia figo spreng.)叶绿体DNA。经BamHI酶切后,白兰和含笑分别产生21和25个片段,其中白兰的各酶切片段在含笑的限制酶图谱对应位置均观察到,白兰和含笑叶绿体基因组大小分别为139.74和143.18kb。两基因组间的遗传距离为0.029。叶绿体DNA限制酶酶切分析可以在分子水平上讨论植物间的系统关系。     

木兰亚纲的分子系统学研究进展：（一）叶绿体rbcL基因序列的分支分析

木兰亚纲的分子系统学研究进展（一）叶绿体ｒｂｃＬ基因序列的分支分析王艇,苏应娟,Ｃ．Ｒ．Ｐａｒｋｓ（中山大学生物系,广州５１０２７５）（美国北卡罗来纳大学生物系）ＰＲＯＧＲＥＳＳＩＮＭＯＬＥＣＵＬＡＲＳＹＳＴＥＭＡＴＩＣＳＯＦＴＨＥＭＡＧＮＯＬＩＩＤ...     

中国木兰属和含笑属导管分子的比较解剖

本文对我国木兰科的39种木兰属和含笑属植物次生木质部的导管分子进行了初步分析。两属导管分子的长度和宽度略有差异。木兰属中多数种的导管分于有单穿孔板,但有的可见到梯状穿孔板。含笑属植物的导管分子大多具有梯状穿孔板,仅有一种可看到单穿孔板。在具有梯状穿孔板的木兰属植物中,穿孔板的横隔数目较含笑属的多。木兰属的导管壁上一般无螺纹加厚;含笑属则相反。此外,在两属之间,导管尚存在一些其它差异。     

基于核基因和叶绿体基因序列的杏属系统发育分析——探讨洪平杏的起源和亲缘关系

洪平杏(Armeniaca hongpingensis C. L. Li)是杏属的一个狭域分布种,基于形态观察被推测为杏(A.vulgaris Lam.)和梅(A. mume Sieb.)的天然杂交种,但目前尚无该种与杏、梅亲缘关系的分子系统学研究。本文以洪平杏的成株和实生苗以及包括杏、梅在内的6种(含1变种)杏属植物为研究材料,分别采用核基因(ITS和SBEI)和叶绿体基因(mat K和ycf1b)序列构建系统发育树,并采用mat K、ycf1b和SBEI基因序列构建单倍型网络图,探讨该物种与杏、梅及杏梅(A. mume Sieb. var. bungo Makino)之间的亲缘关系。基于核基因和叶绿体基因序列分别构建的系统发育树均显示,洪平杏的成株及其全部实生苗个体单独聚为一支,且具有较高的支持率(分别为99/79、71/81),独立于杏属其他种之外。而基于核基因ITS序列的系统发育分析结果表明,洪平杏除极少数成株与杏、杏梅聚为一支外,其余所有成株与实生苗聚为2大支(支持率分别为0.82和0.97),而没有克隆的与梅聚在一起。单倍型分析结果表明,该物种的成株与实生苗在SBEI和ycf1b基因序列中均未检测到杏或梅的单倍型,仅有少数(2/9)的实生苗个体在叶绿体mat K基因序列中检测到杏的单倍型。研究结果不支持将洪平杏定为杏和梅的天然杂交种的观点,推测洪平杏应为一个独立的物种,与杏之间的亲缘关系更近并且存在可检测到的基因流。     

用matK序列分析探讨木兰属植物的系统发育关系

用木兰科Magnoliaceae 57种植物的matK基因序列构建了该科的系统发育分支图。结果表明: (1)木兰属Magnolia L.是一个因为性状的趋同演化而建立的多系类群; (2)木兰亚属subgen. Magnolia和玉兰亚属subgen. Yulania (Spach) Reichenb.亲缘关系较远, 支持将后者从该属中分出建立玉兰属Yulania Spach, 木兰亚属作为木兰属保留; (3)木兰亚属的sect. Splendentes Dandy ex Vazquez组与皱种组sect. Rytidospermum Spach的两个美洲种M. macrophylla Michaux和M. dealbata Zucc.亲缘关系较近, 荷花玉兰组sect. Theorhodon Spach与常绿组sect. Gwillimia DC.的亲缘关系较近; (4)盖裂木属Talauma Juss.可以成立, 而其分布于亚洲的Blumiana Blume组可归入木兰属; (5)拟单性木兰属Parakmeria Hu &; Cheng、华盖木属Manglietiastrum Law以及单性木兰属Kmeria (Pierre) Dandy形成一个单系群, 与玉兰亚属和含笑属Michelia L.的亲缘关系较近。花的着生位置不足以作为木兰科的分族依据, 含笑族Michelieae和木兰族Magnolieae的特征及其界定应做修改。将玉兰亚属从木兰属分出后, 木兰属与含笑属无性状交叉,成为两个区别明显的属。     

基于多基因序列和形态性状的牡丹组种间关系

牡丹被认为是中国的国花,具有很高的医学、观赏和经济价值.野生牡丹被认为是栽培牡丹的野生祖先,因此弄清牡丹组的种间亲缘关系具有重要的理论和实践意义.由于受到信息量的限制,根据单基凼数据或形态数据往往无法对牡丹组的种间关系得到明确的结果.本研究用12份样品代表野生牡丹组(Paeonia section Moutan DC.,Paeoniaceae)8个种,利用包括核基因(Adh1A、Adh2和GPAT)和叶绿体基因(trnS-trnG和rps16-trnQ)的DNA序列以及形态性状的多套数据来探讨野牛牡丹的种间关系.合并分析得到具高支持率的牡丹组物种间的系统发育关系.结果表明,芍药属牡丹组8个野生种分为两个亚组,即肉质花盘亚组subseet.Delavayanae和革质花盘亚组subsect.Vaginatae.肉质花盘亚组包括滇牡丹P delavayi和大花黄牡丹P.ludlowii;革质花盘亚组包括其余6个种.革质花盘亚组中,四川牡丹P.decomposita ssp.decomposita和紫斑牡丹P. rockii ssp. rockii关系密切;卵叶牡丹P.qiui和矮牡丹P. jishanenMs关系密切;银屏牡丹P. suffruticosa ssp.yinpingmudan与风丹P. ostii关系 密切,并且后两个分支为姊妹群.     

基于种皮形态和叶绿体trnL-F对菘蓝属（十字花科）的系统学位置研究

利用种皮微形态观察与叶绿体DNA的trnL内含子和trnL-F基因间隔区序列测定分析相结合,对十字花科菘蓝属植物及其相关属种的系统学关系进行了探讨.研究结果表明原属独行菜族的菘蓝属植物,其种皮特征与原属鸟头荠族的舟果荠属植物相似,同属一类型.而与独行菜族的模式属独行菜属植物、大蒜芥族的模式属大蒜芥属植物以及鸟头荠族的模式属鸟头荠属植物种皮微形态差异显著;在基于叶绿体DNA的trnL内含子和trnL-F基因间隔区序列所构建的系统发育树中,菘蓝属植物与舟果荠属植物距离最近,而与独行菜属、大蒜芥属、鸟头荠属植物具有一定的间隔,结合形态特征,本研究认为,菘蓝属与舟果荠属植物具有较近的亲缘关系,而不是同族的独行菜属植物.     

猕猴桃属植物叶绿体基因PCR-RFLP分析

分别用2个不同限制性内切酶对猕猴桃属27个种和15个栽培品种的叶绿体基因(rbcL基因和psbA基因)的PCR扩增产物进行酶切分析,共得到25个限制性位点,其中24个具有多态性。确立了该属植物的单元型分布,对该属植物的系统发育方式和部分重要种类的亲缘关系进行了探讨,拓展了可用于该属植物分子系统学研究的遗传信息。     

Monophyly and generic relationships of polemoniaceae based on matK Sequences

Polemoniaceae are often considered a model family for studying evolutionary processes, yet a reliable phylogeny for the family is only now beginning to emerge. To test the monophyly of this family and to elucidate intergeneric relationships, we employed comparative sequencing of the chloroplast gene matK. Parsimony analysis of matK sequences representing 18 genera of Polemoniaceae and nine families from Asteridae sensu lato places Polemoniaceae apart from Solanaceae near Fouquieriaceae, Ericaceae, Sarraceniaceae, and Diapensiaceae. Both this and a subsequent analysis of 59 species of Polemoniaceae indicate that Cobaea is derived from within Polemoniaceae, rather than being the sister to Polemoniaceae as suggested by some authors. The tropical genera Bonplandia, Cantua, and Cobaea form a clade, and the remaining, primarily temperate genera, excluding Acanthogilia, form a second monophyletic group. Acanthogilia is placed ambiguously as sister to either the tropical or temperate groups depending on the location of the root for Polemoniaceae. Within the temperate lineage, Polemonium is sister to three large clades: a well-supported clade comprising Phlox, Gymnosteris, Linanthus, Leptodactylon, and Gilia filiformis; a moderately well-supported clade comprising Allophyllum, Collomia, Navarretia, and several species of Gilia; and a weakly supported clade comprising Eriastrum, Ipomopsis, Langloisia, Loeseliastrum, Loeselia, and several species of Gilia. In addition to revealing the extreme polyphyly of Gilia, this analysis suggests that Ipomopsis and Linanthus are also polyphyletic.     

matK and rbcL gene sequence data indicate that Saxifraga (Saxifragaceae) is polyphyletic

The large genus Saxifraga, which consists of ≈400 morphologically and cytologically diverse species, has long been considered taxonomically complex. Phylogenetic analysis of over 2500 bp of chloroplast sequence data derived from matK and rbcL was employed to examine relationships among sections of Saxifraga, the segregate genera Zahlbrucknera, Saxifragopsis, and Cascadia, and the relationships of these taxa to other Saxifragaceae sensu stricto. Phylogenetic trees resulting from separate analyses of the matK and rbcL sequences were highly congruent; phylogenetic analysis of a combined matK–rbcL data matrix was therefore also conducted. Our analyses indicate that Saxifraga is polyphyletic, comprising two well-differentiated clades. One clade, Saxifraga sensu stricto, is the sister to the remainder of the family and consists of Saxifraga sections Irregulares, Heterisia, Trachyphyllum, Cymbalaria, Mesogyne, Xanthizoon, Porphyrion, Ciliatae, Cotylea, Ligulatae, Saxifraga, and Gymnopera. With the exception of Gymnopera, the species-rich sections of this clade are monophyletic. Also part of this clade is the problematic Zahlbrucknera paradoxa, which is allied with members of section Saxifraga. A second major clade of Saxifraga species, Micranthes sensu lato, comprises the large section Micranthes, as well as the segregate genus Cascadia, and S. tolmiei of section Merkianae. This clade is allied with the Heuchera, Darmera, and Chrysosplenium-Peltoboykinia groups of genera. The segregate genus Saxifragopsis is only distantly related to species of Saxifraga, and is instead the sister to Astilbe. The monotypic Oresitrophe is confirmed as a member of the Darmera group of genera. These results suggest that the floral features used to define Saxifraga may simply be symplesiomorphic in these well-separated Saxifraga lineages. Furthermore, the enormous cytological diversity encompassed by Saxifraga likely represents two independent instances of extensive aneuploidy and polyploidy in Saxifragaceae.     

木兰科植物订正

对部分国产木兰科种类进行了订正,归并7个新异名,澄清Mognolia odoratissima Law et R.Z.Zhou和Michelia sphaerantha C.Y.WuexLaw et Y.F.Wu两个种分类上的混乱。     

Chloroplast diversity in the genus Malus: new insights into the relationship between the European wild apple (Malus sylvestris (L.) Mill.) and the domesticated apple (Malus domestica Borkh.)

To unravel the relationship between the European wild apple, Malus sylvestris (L.) Mill., and its domesticated relative M. domestica Borkh., we studied chloroplast DNA variation in 634 wild and 422 domesticated accessions originating from different regions. Hybridization between M. sylvestris and M. domestica was checked using 10 nuclear microsatellites and a Bayesian assignment approach. This allowed us to identify hybrids and feral plants escaped from cultivation. Sixty-eight genotypes belonging to 12 other wild Malus species, including 20 M. sieversii (Ledeb.) Roem. accessions were also included in the analysis of chloroplast diversity. Marker techniques were developed to type a formerly described duplication and a newly detected transversion in the matK gene. Chloroplast DNA variation was further investigated using PCR-RFLP (Polymerase Chain Reaction-Random Fragment Length Polymorphism), and haplotypes were constructed based on all mutational combinations. A closer relationship than presently accepted between M. sylvestris and M. domestica was established at the cytoplasmic level, with the detection of eight chloroplast haplotypes shared by both species. Hybridization between M. sylvestris and M. domestica was also apparent at the local level with sharing of rare haplotypes among local cultivars and sympatric wild trees. Indications of the use of wild Malus genotypes in the (local) cultivation process of M. domestica and cytoplasmic introgression of chloroplast haplotypes into M. sylvestris from the domesticated apple were found. Only one of the M. sieversii trees studied displayed one of the three main chloroplast haplotypes shared by M. sylvestris and M. domestica. This is surprising as M. sieversii has formerly been described as the main maternal progenitor of the domesticated apple. This study hereby reopens the exciting discussion on the origin of M. domestica.     

中国木兰科植物修订

对中国产的木兰科植物３个大属即木莲,木兰和含笑进行了分类修订工作,共提出新组合５个,新异名８个,澄清２种和１亚种。     

Molecular Phylogeny of Magnolia (Magnoliaceae) Inferred from cpDNA Sequences and Evolutionary Divergence of the Floral Scents

Magnolia (disjuncts), however, have similar chemical profiles. A molecular phylogeny of Magnoliaceae was constructed to reveal phylogenetic relationships of taxa by sequencing the trnK intron (including the matK coding region), psbA-trnH, and atpB-rbcL intergenic spacer regions of chloroplast DNA from 25 Magnolia, two Michelia, and two Liriodendron taxa. The psbA-trnH spacer region showed twice the sequence divergence (0.0157) of the trnK intron (0.0073) or the matK coding region (0.0077). The strict consensus tree constructed from the combined data set (ca. 3,700 bp) indicated the genus Magnolia was polyphyletic containing Michelia species as ingroup. The clade of Magnolia liliifera var. obovata, M. coco, and M. delavayi formed the first branch. Among the remaining species, two additional large clades were recognized, i.e., one comprised of American evergreen Magnolia species and another of subgenus Yulania. The relationship among sect. Rytidospermum taxa was not clearly resolved. Parsimonious mapping of the floral scent chemical characters was performed onto the molecular phylogenetic tree to discuss evolutionary trends of the floral scent chemistries. Received 7 December 1998/ Accepted in revised form 18 May 1999