几种人参属植物的细胞分类学研究

摘 要 1．观察到四种人参属植物的体细胞染色体数目为：竹节参(P．japonicus) 2n＝24,三七(P．notoginseng)2n＝24,人参(P．ginseng)2n＝44,西洋参 (P．quinquefolius)2n＝48。其中,野生于江西省庐山和井冈山的竹节参的体细 胞染色体数目,不同于日本植物(2n＝48);三七的体细胞染色体数目则为首次 报道。 2．分布区最广的二倍体物种竹节参,应是本属中较原始的类群,四倍体物 种人参、西洋参等可能是本属中较进化的类群。 这个结论不同于化学分类学所 得到的结果。 3．结合这四个种的地理分布资料分析,我们认为：我国的西南地区是本属 的现代分布中心,也是本属的最大变异中心,很可能是本属的始生中心。     

甘草属2种植物的核型研究

用光学显微镜观察了豆科(Leguminosae)甘草属(Glycyrrhiza)2种荒漠植物的染色体,研究结果表明,黄甘草(G.eurycarpa P.C.Li)、腺荚甘草(G．korshinskii G．Grig)的体细胞染色体数目均为2n＝16,核型公式2n＝2x＝16＝16m,属于Stebbins核型的“lA”型。     

葱属根茎组8种植物的染色体数目和核型报道

本文对国产葱属根茎组的8种植物进行了染色体研究,发现染色体数目2n＝16或32,核型属2A 或2B型,对称性较高。其染色体数目和核型分别为：Allium leucocephalum 2n(2x)＝16＝12m+2sm +2st(2SAT); A,strictum 2n(4x)＝32＝16m+4sm+12st;A.ramosum 2n(2x)＝16=14m+2st (2SAT); A．bidentatum 2n(4x)=32＝24m+4sm+4T;A．tenuissimum 2n(2x)=16=10m+4sm+ 2st(2SAT),A．anisopodium 2n(2x)＝16＝12m+2sm+2st(2SAT);A．anisopodium var．zimmermanni anum 2n(4x)＝32＝24m+4sm+4st(4SAT); A．condensatum 2n(2x)＝16＝14m+2st(2SAT)。多数种的染色体资料为国内首次报道。     

几种不同来源的聚合草染色体数目

本文报告了我国现有栽种的三种来源的聚合草细胞学鉴定结果。结果发现 它们的染色体数目均为2n＝40。 从染色体数目看,初步认为我国目前栽种的 三种来源不同的聚合草(朝鲜聚合草、日本聚合草和澳大利亚聚合草)是属于同 一个种,相当于聚合草属的外来聚合草(Symphytum peregrinum Ledeb．)。     

沙冬青染色体数目及核型的研究

本文首次报道了沙冬青的染色体数目及核型,沙冬青 Ammopiptanthus mongolicus (Maxim.)Cheng f.染色体基数目为x＝9,其核型公式为 2n=18=4m十14sm(2SAT)。     

银杉的染色体数目和形态

银杉(Cathaya argyrophylla)的体细胞具有24个染色体(2n＝24),其中一 对为近端着丝点染色体,其余为中部或近中着丝点染色体。从染色体数目看,银杉与松科多数属相同,但与黄杉属(Pseudotsuga)(2n＝26)不同。     

10种菊属(Dendranthema)植物的细胞学研究

对菊属(Dendranthema)在中国分布的10种20个居群的材料进行了细胞学研究,首次报道了异色菊(2n＝18,36)、银背菊(2n＝56)、楔叶菊(2n＝18,72)的染色体数目和核型,以及蒙菊(2n＝18)的染色体数目新纪录,并结合前人的工作,分析了菊属的核型特征和演化趋势,及其与该属分类群的关系。     

浙江产7种菝葜的染色体研究

本文报道浙江产菝葜属smilax 7个种的染色体数目和核型。S．nipponica有两种核型,2n＝26和2n=32,均为3B型,但后一种细胞型的雄株的第一对染色体大小不等,可能为性染色体;S.riparia 2n=30,属3B型;S．siebodii n＝16;S. china有两个染色体数目,2n＝96 和n＝15;S. davidiana 2n=32,属3B型,对减数分裂MI的观察发现n＝16;S．glabra 2n=32,亦属3B型：S. nervo-marginata var．liukiuensis 2n=32,属3C型。讨论了种间在核型上的差异、属的基数、核型演化趋势和性染色体等问题。     

江西九江新公园猫爪草染色体数目错误报道的更正

对江西九江新公园猫爪草染色体数目的报道进行了改正,发现其染色体数目稳定,为2n=16,因此该种并不象前人所报道的那样是一个多倍体复合体。     

迷果芹(\%Sphallerocarpus gracilis)和红三叶

对迷果芹(Sphallerocarpusgracilis(Bess.)K-Pol.)和红三叶(TrifoliumpratenseL.)进行了染色体计数及核型分析.迷果芹的染色体数目为2n=20,核型公式为K(2n)=2x=20=14m+4sm+2st(SAT);核型类型为2A,为较对称核型,该种植物的染色体数目及核型均为首次报道.红三叶的染色体数目有2n=14、16、28、32等类型,本研究首次报道了2n=14的核型公式为K(2n)=2x=14=2M+12m,核型类型为1B,为较原始的对称核型.     

Three new species of Acanthaceae from Ethiopia

Summary  Three new species of Acanthaceae, Lepidagathis pseudoaristata Ensermu, Acanthopale aethio-germanica Ensermu, and Rhinacanthus mucronatus Ensermu, are described from Ethiopia. The three species are illustrated and their distributions mapped. The three new species are also compared to their presumed closest relatives. L. pseudoaristata is restricted to the Bale and Sidamo Regions, A. aethio-germanica is more widely distributed in Ethiopia occurring in the Kefa, Arsi, Sidamo and Bale Regions, and R. mucronatus is a local endemic restricted to the Borana area in the Sidamo Region. The conservation status of each species is also assessed.     

Taxonomic Affinities and Intra- and Interspecific Variation in Bursaphelenchus spp. as Determined by Polymerase Chain Reaction

Identification of closely related nematode species or races can be very difficult when diagnostic characters are plastic and overlapping. In this study we describe the use of polymerase chain reaction technology and direct DNA sequencing on 19 populations of Bursaphelenchus spp. to help understand their taxonomic relationships. The 5'' end of the heat shock 70A gene from Caenorhabditis elegans was used as the target DNA sequence because it contains both coding and non-coding regions. The results indicate that the 19 populations could be divided into five types within B. xylophilus and four types within B. mucronatus. On a larger scale, the data revealed three distinct groups, representing B. xylophilus from North America and Japan, B. mucronatus from Japan, and "B. mucronatus" from Europe. There is sufficient difference between the European and Japanese "B. mucronatus" groups to warrant their consideration as separate species.     

我国原生植物假泽兰(菊科)的细胞学研究

该文研究了我国原生植物假泽兰(Mikania cordata)台湾花莲居群、苗栗居群、宜兰居群以及台北居群的染色体数目和染色体形态。结果表明:所有居群的染色体数目为2n=36,第一对染色体为近中部着丝粒染色体,其长臂中部具有次缢痕,显著大于其余染色体。各居群的核型公式皆为2n=18m+18sm,核型均为2B型,染色体内不对称性指数(A_1)的变化范围为0.38~0.39,染色体之间不对称性指数(A_2)的变化范围为0.30~0.32。此为我国假泽兰居群染色体数目的唯一报道,也是对该种核型的首次报道。结合前人对假泽兰染色体数目的研究结果,认为假泽兰存在种内非整倍性现象,但在中国台湾的居群中目前仅发现基于x=18的二倍体(2n=36)。假泽兰的第一对染色体的长臂中部具次缢痕,与假泽兰属已报道的核型相似,这一次缢痕可作为假泽兰属的细胞学标记。核型资料、野外观察以及ISSR数据显示薇甘菊(M.micrantha)在我国的成功入侵与入侵种和本土种之间的杂交渐渗无关。根据标本记录和野外考察结果,我国假泽兰现在的分布区与过去相比有了很大的缩减,推测生境的破坏和薇甘菊的侵入可能是导致假泽兰在中国台湾地区逐渐消失的主要原因。     

凤仙花近缘种间核型分析与叶表皮微形态研究

为探究凤仙花近缘种植物的细胞学和微形态学方面的亲缘关系,该文选取荔波凤仙花(Impatiens liboensis)及近缘种赤水凤仙花(I.chishuiensis)和管茎凤仙花(I.tubulosa)的根尖和叶表皮为实验材料,采用体细胞染色体常规压片法和叶表皮光学显微镜观察法对凤仙花近缘种植物进行染色体及叶表皮特征研...     

Karyological studies onGentiana sect.Chondrophyllae (Gentianaceae) from China

Nineteen populations of fifteen species ofGentiana sect.Chondrophyllae from China were observed cytologically.Gentiana alsinoides, G. anisostemon, G. asterocalyx, G. exigua, G. heterostemon, G. intricata, G. praticola, G. pseudoaquatica, G. spathulifolia, andG. subintricata all had the same chromosome number of 2n = 20 (or n = 10), whereasG. piasezkii had 2n = 36,G. squarrosa 2n = 38,G. prattii 2n = 18,G. aristata 2n = 14 (n = 7), andG. heleonastes 2n = 12. All these chromosome numbers are documented here for the first time, except forG. squarrosa, where it is a new number report. The basic numbers of x = 6, x = 7 and x = 19 are new for the section. Karyotype analyses of some species revealed that, except for a few cases, the species examined mainly had metacentric chromosomes. 2n = 20 = 2m(SAT) + 18m was found to be the main type of karyotype for the species with 2n = 20. Chromosomal evolution and its mechanism in this section are also discussed.     

Pinewood Nematode Species Complex: Interbreeding Potential and Chromosome Number

Interbreeding potential, chromosome number, and host range were compared among several isolates and species of Bursaphelenchus from diverse geographic areas. Some isolates from North America, Japan, and France had a wide-ranging interbreeding potential, whereas others were restricted in their potential to hybridize with other isolates. Although interbreeding occurred in the laboratory between some "M" and "R" forms of B. xylophilus, interbreeding of B. xylophilus and B. mucronatus was rare. The hybrids had the pathogenicity of the parent with the broader host range. This fact suggests that virulence may be inherited as a dominant character or that increased virulence may have resulted from differences in hybrid vigor. The haploid chromosome number of the different isolates separated the isolates into three groups and distinguished B. xylophilus from B. mucronatus. The findings suggest that the pinewood nematode species complex consists of sibling species that have evolved by reproductive isolation, that the French isolate is a new species, and that B. xylophilus and B. mucronatus have evolved from a common ancestor.     

Inhibitory Effect of Bursaphelenchus mucronatus (Nematoda: Aphelenchoididae) on B. xylophilus Boarding Adult Monochamus alternatus (Coleoptera: Cerambycidae)

Inhibitory effects of Bursaphelenchus mucronatus on the number of B. xylophilus carried by an adult Monochamus alternatus were investigated using artificial pupal chambers. When pupal chambers were infested with either B. xylophilus or B. mucronatus, the load of B. xylophilus onto the beetle was greater (P < 0.001) than that of B. mucronatus. However, within the pupal chamber there was no difference in the abundance of the third-stage dispersal juveniles, which would molt to the fourth-stage dispersal juveniles to board beetles. The nematode load on beetles that emerged from pupal chambers infested with both Bursaphelenchus species was smaller (P = 0.015) than that of beetles with B. xylophilus alone but greater (P < 0.001) than that of beetles with B. mucronatus alone, suggesting an inhibitory effect of B. mucronatus. As a result of this study, the rate of inhibition of B. mucronatus on molting of third-stage dispersal juveniles of B. xylophilus to fourth-stage dispersal juveniles was 0.65, which resulted in great inhibition on boarding beetles at a rate of 0.7.     

Experimental evidence on the affinities ofPapaver somniferum (Papaveraceae)

Results obtained from crossing experiments betweenP. somniferum subsp.somniferum (2n = 22) and subsp.setigerum (2n = 44),P. glaucum (2n = 14) andP. gracile (2n = 14) and from the observation of meiotic chromosome pairing in the various hybrids obtained do not provide straightforward evidence for the hypothesis thatP. somniferum originated as a triploid hybrid between taxa similar toP. glaucum andP. gracile (Kadereit 1986a, b).—On the one hand, the pattern of crossability found reflects the closer similarity of subsp.somniferum toP. glaucum and of subsp.setigerum toP. gracile, which was interpreted as segregation of parental characters, and the high frequency of 2n = 28 chromosomes among F₂-progeny from the hybrid subsp.somniferum × subsp.setigerum (2n = 33) might reveal n = 7 as the base number also ofP. somniferum. On the other hand, however, the general difficulty of obtaining hybrids, and the low incidence of bivalent formation in their meiosis, probably indicating a lack of chromosome homology between the different species, do not fit the above hypothesis.—These results are in marked contrast to the morphological similarity between the three species involved.     

拟松材线虫纤维素酶活性与其致病性关系

【目的】研究拟松材线虫是否分泌纤维素酶以及纤维素酶与其致病力的关系。【方法】对拟松材线虫的不同致病性种群以及松材线虫的虫体蛋白提取液、分泌液的纤维素酶活性进行定量测定,比较群体间纤维素同工酶谱型差异。【结果】拟松材线虫也含有纤维素酶,并向体外分泌;且不同致病性种群的纤维素酶活性与其致病性有一定相关性,致病性越强纤维素酶活性越强。【结论】纤维素酶活性大小是导致拟松材线虫不同种群间致病性差异的重要原因,这对于全面认识松树线虫萎蔫病的致病机理有重要意义。     

中国鹿角兰属(兰科)植物新资料

报道了中国兰科(Orchidaceae)鹿角兰属(Pomatocalpa)一新记录种——纹瓣鹿角兰［P. tonkinense (Gagnep.) Seidenf.］,凭证标本保存于广西植物研究所标本馆(IBK)。纹瓣鹿角兰的花序疏生多数花,萼片、花瓣均具2条紫色条纹,中萼片及花瓣远长于侧萼片,与中国原记录的2种鹿角属植物容易区分。该研究提供了新记录种的形态描述、中国鹿角兰属植物图版及分种检索表。