用RAPD分子标记探讨鹅观草属的种间关系

通过34个10碱基随机引物对鹅观草属(RoegneriaC.Koch)26个物种进行PCR扩增,28个引物能产生多态带。在NTSYS程序中,对16个引物扩增的186条扩增产物,计算Jaccard遗传相似系数,建立UPGMA聚类图。结果表明:(1)物种间遗传差异明显,具有丰富的遗传多样性;(2)StY和StYH基因组的物种存在着一定的遗传差异,并各有一定程度的分化,这种分化是与地理位置相联系的。相距越远,物种相似程度越低;(3)形态差异较小,基因组同源,地理分布一致的物种聚类在一起,表现出较密切的亲缘关系;(4)无芒类群的R.alashanicaKeng和R.magnicaespes(D.F.Cui)L.B.Cai与其余分析的24个Roegneria物种存在着极大的遗传差异;(5)分布于西亚的R.caucasicaC.Koch.与分布于东亚和中亚的物种存在着较大的RAPD变异,亲缘关系较远;(6)在对R.ciliaris(Trin)Nevski和R.japonensis(Honda)Keng、R.tenuispicaJ.L.YangetY.H.Zhou和R.pendulinaNevski、R.tsukushiensis(Honda)Ohwi和R.kamojiOhwi等的分类处理上,基本上与形态学和细胞学的研究结果一致。对RAPD标记在Roegneria系统分类研究中的应用进行了讨论。     

鹅观草属五个类群的核型与进化

报道了鹅观草属５个类群的核型,即长芒鹅观草,核型２ｎ＝４ｘ＝２８＝２２ｍ＋６ｓｍ（２ＳＡＴ）;短颖鹅观草,核型２ｎ＝４ｘ＝２８＝２０ｍ（２ＳＡＴ）＋８ｓｍ（２ＳＡＴ）;短柄鹅观草,核型２ｎ＝４ｘ＝２８＝２２ｍ（２ＳＡＴ）＋６ｓｍ;纤毛鹅观草,核型２ｎ＝４ｘ＝２８＝２０ｍ＋８ｓｍ（４ＳＡＴ）;毛盘鹅观草,核型２ｎ＝４ｘ＝２８＝１８ｍ＋６ｓｍ（４ＳＡＴ）＋４ｓｔ。同时,通过核型重要性状的递变分析,揭示了鹅观草属５个类群的相对进化程度以及宏观分类中４个组的系统发育关系,表明鹅观草属的半颖组在系统发育中可能既派生了颖体短小的小颖组,又派生了颖体长大的大颖组和长颖组。     

青海鹅观草属的叶片表皮微形态特征及其分类意义的探讨

通过青海鹅观草属叶片表皮的解剖观察,结合外部形态,表明了该属植物在小麦族中共族分属的合理性,同时对青海地区属下类群重新进行了确认,共划分2组16种,即拟技碱草组,包括6种;弯穗草组,包括10种．过去处理的种短柄鹅观草和多秆鹅观革分别作为短颖鹅观草和缘毛鹅观草的变种。此外,类群间的演化水平和属的地理起源也作了初步探讨。     

国产前原鹅观草的订正

对我国文献中记载的前原鹅观草（Ｒｏｅｇｎｅｒｉａｍａｙｅｂａｒａｎａ（Ｈｏｎｄａ）Ｏｈｗｉ）的标本和植物,与原产于日本的该种进行了比较形态学、细胞学研究,二者差异显著。作者认为我国所记载的该种种名应是山东鹅观草（Ｒｏｅｇｎｅｒｉａｓｈａｎｄｏｎｇｅｎｓｉｓ（Ｂ．Ｓａｌｏｍｏｎ）Ｊ．Ｌ．Ｙａｎｇ,Ｙ．Ｈ．ＺｈｏｕｅｔＹｅｎ）,其内稃先端钝圆,长为外稃的３／４,染色体数为２ｎ＝４ｘ＝２８,具ＳＹ染色体组,结实率达９０％以上,过去被错定为Ｒ．ｍａｙｅｂａｒａｎａ。而Ｒ．ｍａｙｅｂａｒａｎａ在日本系一天然杂种,其内稃先端尖,与外稃等长或稍短,染色体数为２ｎ＝６ｘ＝４２,具ＨＳＹ染色体组,结实率极低,仅０．２％～０．４％。     

小麦族鹅观草属三种植物的生物系统学研究

本文研究了禾本科小麦族鹅观草属的3个种:缘毛鹅观草(Roegneria pendulina Neuski 2n=4x=28),纤毛鹅观草(R. ciliaris (Trin.) Nevski 2n=4x=28)和鹅观草(R. kamoji Ohwi 2n=6x=42)及其种间杂种的形态变异和染色体配对行为。各杂种F_1的减数分裂染色体配对数较高,但杂种高度不育。在杂种减数分裂中还观察到一定频率的多价体形成。以上结果充分表明该3种植物享有两个共同的基本染色体组,在S和Y染色体组之间发生过染色体相互易位,缘毛鹅观草的染色体组可拟定为S~PY~P。     

分布于日本和中国的鹅观草及其杂种的形态学和细胞学研究

本文对分布于日本的Agropyron tsukushiense (Honda) Ohwi var. transiense (Hack.) Ohwi (2n=6x=42)和分布于中国的Roegneria kamoji Ohwi (2n=6x=42)及其杂种F_1(2n=6x=42)进行了形态学及细胞学的研究,并同时探讨了亲本种的亲缘关系。总体来看,亲本材料之间在形态上虽有差异但并不十分显著。杂种F_1的形态特征介于其父、母本之间。在减数分裂过程中,亲本种和杂种F_1的染色体配对行为均十分正常。但在检查了大量的成熟花粉和穗状花序之后,发现杂种F_1有部份不育现象。上述研究结果表明A. tsukushiense var. transiens的三个染色体组与R. kamoji的三个染色体组同源。结合形态学和育性等方面的研究资料,作者认为上述两个材料仍应属于同一分类等级。但必须指出,由于长期的地理隔离,他们之间产生了一定的形态变异和生殖障碍。按照国际植物命名法规(ICBN)上述两个材料应组合为:Roegneria tsukushiensis (Honda) B. R. Lu, Yen et J. L. Yang及其变种var. transiens (Hack.) B. R. Lu, Yen et J. L. Yang comb. nov.     

鹅观草属4个种核型与进化的研究

报道了鹅观草属(Roegneria C. Koch)4个种的核型,即中华鹅观草,核型为2n=4x=28=28m(2SAT);裸穗鹅观草,核型为2n=4x=28=24m+4sm(2SAT);缘毛鹅观草,核型为2n=4x=28=22m+6sm(2SAT);缘穗鹅观草,核型为2n=4x=28=24m(2SAT)+4sm。4个种核型的共征和自征反映了形态划分中共属分种的合理性。尤其通过核型不对称性和相对进化程度的分析,表明中华鹅观草最原始,缘穗鹅观草最进化,裸穗鹅观草和缘毛鹅观草演化居中;狭颖草系高级于缘毛草系。核型不对称性所表示的进化程度似乎与系间颖芒的发生,种间花序的增长变粗、外稃芒的延伸相关。     

披碱草属(Elymus L.)两个物种之订正

披碱草属Elymus L．是小麦族Triticeae Dumort．中最大的属,全世界共有150多个种,广泛分布于 温带地区。我国约有80余种(包括鹅观草属Roegneria C．Koch),是披碱草属的重要分布区和多样性分 化中心。由于披碱草属植物种类繁多、分布广泛、生境多样以及形态变异较为复杂,导致该属在分类上 存在许多问题。同时,由于地域的局限和地区间交流的缺乏,致使同一种披碱草属植物被不同的学者多 次发表及同物异名现象的出现。本文对E．antiquus和E．burchan-buddae这两个曾多次被订名的披碱草 属物种进行了分类订正。     

利用RAPD分析披碱草属、鹅观草属和猬草属模式种的亲缘关系

利用随机扩增多态性DNA（RAPD）技术对小麦族披碱草属、鹅观草属和猬草属3个属的模式种进行了基因组DNA多态性分析。42个引物产物的290条谱带中,257条（88.62%)表现出多态性,说明披碱草属、鹅观草属和猬草属3个属的模式种间具有丰富的遗传多样性。利用290个RAPD标记,计算材料间Nei氏遗传相似性系和遗传距离,在NTSYS程序中利用UPGMA进行聚类。结果表明,Elymus sibiricus种不同居群间的遗传差异较小,遗传距离在0.097-0.180之间。E.sibiricus,Roegneria caucasica和Hystrix patula的种间遗传差异明显,遗传距离在0.458-0.605之间。H.patula与E.sibiricus的亲缘关系较近。R.caucasica与E.sibiricus的亲缘关系较远。     

鹅观草属三个种的形态变异与核型的研究

本文通过对鹅观草属的三个种:鹅观草(Roegneria kamoji Ohwi)、纤毛鹅观草(R. ciliars (Trin.) Nevski)和竖立鹅观草(R. japonensis(Honda)Keng)的形态学比较和核型分析研究了该三个种的系统关系。R. kamoji与R. ciliaris、R. japonensis形态上的差异明显,而后二个种差异甚小,难以进行划分。R. kamoji的核型公式为:2n=6x=42=30m+8sm+4SAT;R. ciliaris为:2n=4x=28=18m+6sm+4SAT;R. japonensis为:2n=4x=28=18m+6sm+4SAT。t-测验的结果表明R. ciliaris与R. japonensis的核型无显著差异。因此笔者认为R. ciliaris和R. japonensis应合并为一种系内的分类群。     

Cytological Studies of Hybrids of Roegneria ciliaris with R.alashanica and R.magnicaespes(Poaceae:Triticeae)

In order to investigate the relationships between Roegneria.ciliaris(Trin.)Nevski and R.alashanica Keng,and between R.ciliaris and R.magnicaespes D.F.Cui.R.ciliaris(Trin.)Nevski was crossed with the other two species,through the aid of embryo rescue. Hybrids were obtained from these two combinations.Chromosome pairing behavior of parents an dhybrids was observed at metaphase I of pollen mother cells. Meiotic configuratons were 10.62Ⅰ＋8.17Ⅱ＋0.32Ⅲ＋0.02Ⅳ for R.ciliaris×R.magnicaespes and 18.00Ⅰ＋4.76Ⅱ＋0.16Ⅲ for R.ciliaris ×R.magnicaespes;c-value of the two hybrids were 0.44 and 0.21,respectively.     

鹅观草与大鹅观草杂种的细胞遗传学及形态学研究

大鹅观草（ Ｒｏｅｇｎｅｒｉａ ｇｒａｎｄｉｓ Ｋｅｎｇ） 是分布于我国陕西的一种多年生四倍体植物。为了探索大鹅观草与鹅观草（ Ｒｏｅｇｎｅｒｉａ ｋａｍｏｊｉ Ｏｈｗｉ） 间的物种生物学关系, 通过对其进行远缘杂交,幼胚离体培养, 合成了远缘杂种; 并对亲本及杂种Ｆ１ 代花粉母细胞减数分裂中期Ⅰ染色体配对行为及形态学进行了研究。结果表明杂种Ｆ１ 减数分裂染色体配对平均构型为： Ｒ－ ｋａｍｏｊｉ ×Ｒ－ｇｒａｎｄｉｓ１０－２６ Ⅰ＋ １２－３７ Ⅱ（ｃ－ 值＝ ０－７４） , 大鹅观草与鹅观草所含的ＳＹ 染色体组间存在较大的同源性分化; 杂种穗部特征大多数介于双亲之间。     

鹅观草属4个种的核型与进化

报道了4个种鹅观草属（Roegneria C. Koch）植物的核型,其核型公式如下：芒颖鹅观草(R. aristiglumis Keng et S. L. Chen), 2n=4x=28=22m+6sm（2SAT）;短颖鹅观草(R. breviglumis Keng), 2n=4x=28=20m（2SAT）+8sm;红原鹅观草(R. hongyuanensis L. B. Cai), 2n=4x=28=22m+6sm（2SAT）;山东鹅观草(R. shandongensis（B. Salomon）J. L. Yang, Y. H. Zhou et Yen), 2n=4x=28=24m（2SAT）+4sm。同时对染色体主要特征的演变规律进行了分析,揭示了鹅观草属4个种的相对进化程度以及宏观分类中2个组的系统发育关系,表明鹅观草属的半颖组在系统发育中派生了颖体短小的小颖组。     

种间杂种染色体配对所揭示的披碱草属植物StY基因组分化及其进化意义

在同倍体(homoploid)植物杂交-分化的物种形成(speciation)过程中,杂交后代与亲本之间的有效生殖隔离是新物种形成的关键。杂种与亲本在时间、空间、生态环境和基因水平上的隔离,保证了杂种后代的分化和稳定,并逐渐形成新物种。为了研究披碱草属(Elymus)含StY基因组四倍体物种的系统演化关系,本文对来自亚洲不同地理分布区的26种披碱草属植物进行了大规模的种间杂交和杂种F1减数分裂染色体配对行为的分析。结果表明各物种之间有不同程度的杂交亲合力,杂交结实率在各杂交组合之间有较大的变异(在4．8％-100％之间);但各物种之间的杂种F1完全不育。证明各物种之间形成了明显的生殖隔离。种间杂种F1减数分裂中期-I染色体配对分析的结果进一步表明,StY基因组随各披碱草属物种地理分布的不同而有不同程度的分化。来自同一分布区(如东亚或西亚分布区之内)物种的StY基因组分化程度较低,但来自不同分布区(如东亚和西亚)物种之间相同的StY基因组具有显著的分化。表明地理隔离对含StY基因组物种的分化起到了十分重要的作用。通过对种间和种内杂种F1的减数分裂异常现象和染色体配对频率变化规律的分析,作者认为细胞学水平的变化,如基因组同源性的分化和染色体结构的变异等都在杂种后代与亲本之间产生生殖隔离并逐渐形成新物种的进化过程中起到了积极的作用。     

Genome constitution of Elymus tangutorum (Poaceae: Triticeae) inferred from meiotic pairing behavior and genomic in situ hybridization

Elymus tangutorum (Nevski) Hand.-Mazz (2n = 6x = 42) is a perennial species in the tribe Triticeae, which distributes in Nepal and north and northwest China. However, the genome constitution of E. tangutorum is controversial and its taxonomic status is not clear. Hybridizations of E. tangutorum were carried out with E. wawawaiensis J. R. Carlson & Barkworth (StH), Roegneria grandis Keng (StY), and E. dahuricus Turcz. ex Griseb. (StYH). Meiotic pairing in the hybrids E. tangutorum × E. wawawaiensis (StH), E. tangutorum × R. grandis (StY), and E. tangutorum × E. dahuricus (StYH) averaged 10.48, 11.12, and 20.92 bivalents per cell, respectively. The results suggested that E. tangutorum is an allohexaploid and contains the StYH genomes. Results of genomic in situ hybridization analysis strongly supported the chromosome pairing data. Therefore, E. tangutorum should be treated as Campeiostachys dahurica var. tangutorum (Nevski) B. R. Baum, J. L. Yang & C. Yen. Intergenomic rearrangements of E. tangutorum may be affected by environmental factors.     

以礼草属的分类研究

以礼草属Kengyilia Yen et J. L. Yang 是禾本科Poaceae小麦族trib．Triticeae中新近建立的屑,针对其存在问题,对它进行了全面清理,提出了一个新的分类系统。新系统含3组、26种、6变种,其中3个组为新设立,并包括1新种、7个新等级、新组合及新异名。此外,还报道了一些类群的分布新记录。     

A taxonomical study on the genus Kengyilia Yen et J. L. Yang

Kengyilia Yen et J L Yang is a recently established genus in trib. Tritieeae of Poaceae. In this paper, this genus is taxonomically revised, and a new taxonomic system is presented. The new system includes 3 sections, 26 species and 6 varieties, of which 3 sections and 1 species are described as new, 7 taxa are treated respectively in the ways of new status or combination and reduction. Three new sections, sect. Kengyilia, sect. Stenachyra L. B. Cai and sect. Hyalolepis (Nevski) L. B. Cai, are differentiated by the length and width of spike, the growing position of spikelet, the relative length of glume, the colour of anther and so on. The sect. Kengyilia contains 9 species, distributed in northwestern China, extending westward to Kazakhstan, Kirghizia, Tadzhikistan, Afghanistan and Iran; the sect. Stenachyra L. B. Cai comprises 10 species and 3 verieties, distributed in western China, mainly in the Qinghai-Xizang Plateau; and the sect. Hyalolepis (Nevski) L. B. Cai consists of about 7 species and 3 varieties, distributed in western China, extending westward to Kirghizia and Tadzhikistan. Twenty-six species of Kengyilia are recognized on the basis of the same criterion of specific concept, and the other taxa below the rank of species are also checked in terms of their external morphology. As a result, Kengyilia pen~ dula L. B. Cai is reported as a new species; K. hirsuta var. obviaristata L. B. Cai is raised to a species; K. melanthera (Keng) J. L. Yang, Yen et Baum is reduced to a variety under K. thoroldiana (Oliver) J. L. Yang, Yen et Baum; Roegneria hirsuta var. leiophylla Keng et S. L. Chen is reduced as a synonym of K. hirsuta var. hirsuta; Agropyron thoroldianum var. lasciusculum Melderis is reduced to K. grandiglumis (Keng et S. L. Chen) J. L. Yang, Yen et Baum; Roegneria rigidula var. intermedia Keng et S. L. Chen to K. rigidula (Keng et S. L. Chen) J. L. Yang, Yen et Baum; R. hirsuta var. variabilis Keng et S. L. Chen and R. rnelanthera var. tahopaica Keng et S. L. Chen to K. hirsuta (Keng et S. L. Chen)J. L. Yang, Yen et Baum. In addition, new records onthe geographical distributions of some taxa are also reported in this paper.     

Phylogenetic analysis of the species with awnless lemma in Roegneria (Poaceae,Triticeae) based on single copy of nuclear gene DMC1

To investigate the phylogenetic relationships among species with awnless lemmas in Roegneria and their related diploid genera, the possible genomic constitution and genome donor of species with awnless lemmas in Roegneria, phylogenetic analyses of disrupted meiotic cDNA (DMC1) sequences were investigated in this study. The results showed that: (1) Roegneria alashanica-1 grouped with the Y-type sequences and Roegneria alashanica-2 grouped with the St-type sequences, confirming that Roegneria alashanica has the StY genomes. (2) Roegneria grandis-1 grouped with the Y-type sequences and Roegneria grandis-2 grouped with the St-type sequences, confirming that Roegneria grandis has the St^gY genomes, where the St genome from R. grandis is different from the St genome but is homologous with the Y genome. (3) Two Roegneria elytrigioides sequences grouped with the St-type sequences, confirming that Roegneria elytrigioides has the St₁St₂ genomes and should therefore be classified as Pseudoroegneria elytrigioides. (4) We prefer the suggestion that the Y genome is closely related to the St genome, however, the data do not certify that the St and Y genomes have the same origin.     

Genomic constitution and taxonomy of the Chinese hexaploids Elymus cylindricus and E. breviaristatus (Poaceae: Triticeae)

Elymus cylindricus (2n = 6x = 42) and E. breviaristatus (2n = 6x = 42) are distributed in grasslands and deserts of northern and north‐western China. Their genomic constitution and taxonomic status are unclear. Elymus cylindricus was crossed with E. wawawaiensis J.R.Carlson & Barkworth ( StH ), Roegneria grandis Keng ( StY ) and Campeiostachys dahurica (Turcz. ex Griseb.) B.R.Baum, J.L. Y ang & C. Y en var. dahurica ( StYH ). Meiotic pairing in the hybrids E. cylindricus × E. wawawaiensis ( StH ), E. cylindricus × R. grandis ( StY ) and E. cylindricus × C. dahurica var. dahurica ( StYH ) showed on average 10.00, 11.30 and 20.92 bivalents per cell, respectively. Elymus breviaristatus was crossed with C. dahurica var. dahurica ( StYH ) and E. cylindricus. Chromosome pairing in the hybrids of E. breviaristatus × C. dahurica var. dahurica and E. breviaristatus × E. cylindricus showed on average 19.60 and 19.27 bivalents, respectively. Genomic in situ hybridization (GI SH ) revealed the presence of St , Y and H genomes in E. cylindricus and E. breviaristatus. An intergenomic rearrangement was observed in E. cylindricus using GI SH . Meiotic pairing data and GI SH indicated that both E. cylindricus and E. breviaristatus are allohexaploids containing the StYH genomes. Elymus cylindricus and E. breviaristatus should be treated as Campeiostachys dahurica var. cylindrica and Campeiostachys breviaristata, respectively.     

Genetic relationships among <Emphasis Type="Italic">Hystrix patula,H. duthiei</Emphasis> and <Emphasis Type="Italic">H. longearistata</Emphasis> according to meiotic studies and genome-specific RAPD assay

Hybrids including Hystrix patula, H. duthiei and H. longearistata were obtained and genetic relationships among them were studied. Meiotic pairing in hybrids of H. duthiei × Psathyrostachys juncea (Ns), H. longearistata × Psa. juncea (Ns), Leymus multicaulis (NsXm) × H. duthiei, L. multicaulis (NsXm) × H. longearistata, Elymus sibiricus (StH) × H. patula, Roegneria ciliaris (StY) × H. patula, R. ciliaris (StY) × H. duthiei and R. ciliaris (StY) × H. longearistata averaged 5.76, 5.44, 11.94, 10.88, 10.08, 3.57, 0.46 and 0.90 bivalents per cell, respectively. The results indicated that H. duthiei and H. longearistata had the NsXm genomes of Leymus, while H. patula contained the StH genomes and had a low genome affinity with the StY genomes of Roegneria. Results of genome-specific RAPD assay were comparable with the chromosome pairing data. According to the genomic system of classification in Triticeae, H. patula should be considered as Elymus hystrix L., while H. duthiei and H. longearistata as Leymus duthiei and Leymus duthiei ssp. longearistata, respectively.