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1.
稻属药稻复合体Oryza officinalis complex中有5个二倍体物种，涉及B、C和E3个染色体组，分布在亚洲、非洲和大洋洲。其中，O.australiensis是稻属中惟一含E染色体组的物种;O.punctata则是惟一含B染色体组的物种。虽然O.officinalis、O.rhizomatis和O.eichingeri都含C染色体组，但由于它们间断分布在亚洲和非洲，可能在稻属异源多倍体成种中发挥了不同作用。染色体组B、C和E之间，以及上述二倍体物种之间的系统发育关系及其在稻属多倍体物种形成 相似文献
2.
风毛菊属Saussurea DC.是菊科物种分化十分剧烈和分类处理十分困难的一个属。该属的单系起源性质、属下分类系统以及一些独特形态物种的系统位置尚不清楚，有待进一步验证。本文测定了代表该属5个亚属37种植物43个样品和川木香属Dolomiaea DC.的１种样品的叶绿体DNA trnL-F序列，并调取菜蓟族Cardueae Cass.与风毛菊属具有一定亲缘关系的13属的该序列，一起进行了分支分析，重点验证该属的属下形态分类系统以及形态特殊、青藏高原地区特有的雪兔子亚属subgen. Eriocoryne 相似文献
3.
中国车前属种子形态及其分类学意义 总被引：1，自引：0，他引：1
本文研究了中国车前科Plantaginaceae车前属plantago2亚属8组17种及1变种植物的种子，
在扫描电子显微镜下的形态及亚显微结构(种皮纹饰)．结果表明种子形态有四个类型：1，多角形类型；2．舟形类型；3．卵形类型；4．矩圆形类型。各个种的种子形态和种皮纹饰有着相当明显的区别。新种plantago densiflorus的建立应用了种子形态和种皮纹饰这一特征。车前种子形态分类与pilger用植物其他形态特征建立的车前属分类系统是一致的，因此，笔者支持Pilger的车前属分类系统。 相似文献
4.
本文对稻属Oryza L. 23种植物叶片表皮的结构特征进行了观察和研究,结果表明:叶表皮的某
些性状,如在叶片脉带之间长细胞中乳突的大小和分布以及叶表皮气孔器上小乳突的数目和着生位置
在稻属的各种之间有着一定的变异规律,这在稻属各种的分类和其系统关系的研究中有一定的价值。
综合这些性状的变异特征,按照叶片下表皮脉间长细胞中乳突的大小和分布特征以及气孔器中小乳突
的数目和着生位置可将稻属这23个物种分为3组。第一组包括长颖野稻、马来野稻、疣粒野稻和颗粒
野稻,这些种的叶表皮脉间长细胞中没有大乳突和中乳突,仅偶见极稀疏分布的小乳突,气孔器中均无
小乳突。第二组包括短药野稻、二倍体和四倍体药用野稻、小粒野稻、紧穗野稻、斑点野稻、阔叶野稻、高
株野稻、大颖野稻、根茎野稻和澳洲野稻,这些种的叶表皮脉间长细胞中通常没有大、中乳突,但密布小
乳突,且大多数种的气孔器保卫细胞的近两端各有2个小乳突。第三组包括栽培稻、一年生普通野稻、
多年生普通野稻、长雄蕊野稻、展颖野稻、南方野稻、矮舌野稻、非洲栽培稻和希来特野稻,这些种的叶
表皮脉间的长细胞中常有大乳突、中乳突和小乳突,而气孔器保卫细胞的近两端各有2个明显的小乳
突,并同时常在气孔器副卫细胞的近内缘还有2～4个小乳突。 相似文献
5.
卢宝荣 《中国科学院研究生院学报》2002,40(6):539-545
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。 相似文献
6.
通过扫描电镜对国产水鳖科植物(包括6属13种)的种皮微形态特征进行观察，并作了系统描述。根据种皮细胞形态、外种皮表面纹饰和内种皮内层小瘤状突起的特点将水鳖科植物的种皮微形态特征划分为3种类型，即海菜花型(海菜花属)、水鳖型(水鳖属)和苦草型(苦草属、水筛属、虾子草属和黑藻属)，并作出了分属检索表。本文结果表明，种皮微形态特征可作为该科族、属以及属内种级水平分类的依据，对探讨属间关系和该科的系统发育关系亦具有重要的价值。种皮微形态特征支持Hutchinson(1959)和Eckhardt(1964)将海菜花属和水鳖属分别作为一个独立的族处理的观点。苦草属、水筛属和虾子草属种皮微形态特征的高度相似性表明它们间有密切的联系，不支持将它们置于不同亚科和族的分类处理。黑藻属虽与上述3属近缘，但其外种皮特征则较为独特，因此与水筛属放在不同族中更为合理。本文种皮微形态特征的研究结果支持iki1937)和Shaffer-Fehre(1991b)等关于水鳖科与茨藻科近缘的观点。 相似文献
7.
文章针对已整理和修订的西藏野生兰科植物名录中89属336种兰科植物按照IUCN评价标准分为灭绝、野外灭绝、极危、濒危、易危、近危、无危和数据缺乏等8个等级。结果表明,西藏野生兰科植物中没有灭绝和野外灭绝的物种。其中,有3属3种为极危(CR),占总物种数的0.89%,分别为墨脱毛兰(Eria medogensis)、狭叶盆距兰(Gastrochilus linearifolius)和矮小独蒜兰(Pleione humilis)。处于濒危(EN)的有24属34种,占总物种数的10.1%;处于近危(NT)的有28属55种,占总物种数的16.1%;缺乏数据(DD)的有34属67种,占总物种数的17.9%;无危(LC)的有50属115种,占总物种数的34.2%;易危(VU)的有36属70种,占总种数的10.8%.其中,极危、濒危、易危、近危的物种主要集中分布在1500-3000 m海拔段内,分别占该海拔的85.7%、48.5%、59.3%和56.2%.濒危等级评价结果将为西藏野生兰科植物研究、保护策略的制定提供科学依据。 相似文献
8.
在植物的系统与进化研究中，相对于叶绿体和核基因片段来说，线粒体基因片段由于其分辨率较低、结构复杂而较少应用到系统学研究中。本研究选用nad1基因的第2内含子序列探讨了稻族Oryzeae的系统发育关系，并着重分析了单型属Porteresia的系统学位置，并在此基础上探讨了nad1基因内含子序列的系统学意义以及空位性状在系统发育重建中的价值。本研究结果支持将稻族分为两个亚族（Oryzinae和Zizaniinae）的处理，稻族中假稻属Leersia与稻属Oryza最近缘，Porteresia coarctata不应该单独成属而应处理为稻属的成员。本研究表明，nad1第2内含子具有一定的系统发育信息，尤其是在较高分类等级的系统发育重建中具有较大价值；同时表明空位的合理利用将在已有序列信息基础上提供更多的系统发育信息。 相似文献
9.
拉鲁湿地国家级自然保护区保护着其独特的高寒湿地生态系统和丰富的生物多样性，但随着气候变化和人类活动的干扰，入侵植物已出现在拉鲁湿地，对湿地生物多样性和生态系统稳定性构成了潜在威胁。为了解其本底状况，本研究以样线法对拉鲁湿地入侵植物进行了调查，通过9条样线74个样点的实地调查研究，发现：拉鲁湿地共有入侵植物29种，隶属于10科25属，主要为菊科(11种)、豆科(5种)和禾本科(4种)，出现频度最高的种类依次是：苦苣菜(Sonchus oleraceus)、灰绿藜(Chenopodium glaucum)、牛膝菊(Galinsoga parviflora)；从入侵等级来看，具有明显入侵性的物种有13种，包括4种恶性入侵物种和9种严重入侵物种；拉鲁湿地外来入侵植物区系在属的水平上具有明显的温带性质，美洲起源的植物占据主要优势。拉鲁湿地主要有8种生境，已在其中6种生境中发现入侵植物，人工林生境发现的入侵植物种类高达26种。 相似文献
10.
本文对分布于我国的椴树科(Tiliaceae)9属44种植物的花粉形态进行了光学显微镜
的系统观察，并对其中10种花粉的外壁细微结构进行了扫描电镜观察。本科花粉为长球形、
扁球形和球形，萌发孔为长3孔沟、短3孔沟和3(一4)孔三种类型，外壁主要为网状纹饰，个 别属为刺状纹饰。根据花粉资料，本文还探讨了该科植物分类中的某些问题。 相似文献
11.
12.
马金双 《中国科学院研究生院学报》1989,27(5):321-364
本文通过对东亚和南亚马兜铃属的研究，修改了马兜铃属的分类系统，补充论证了演化趋势；并
在分析该属地理分布的基础上提出马兜铃属分布与分化的第二个中心——中国的横断山区。 本文确
认2亚属、7组、4系、68种和1变种，其中有3新组、2新种及13个新异名。 相似文献
13.
BackgroundAvailability of related rice species is critical for rice breeding and improvement. Two distinct species of domesticated rice exist in the genus Oryza: Oryza sativa (Asian rice) and Oryza glaberrima (African rice). New rice for Africa (NERICA) is derived from interspecific crosses between these two species. Molecular profiling of these germplasms is important for both genetics and breeding studies. We used 30 polymorphic SSR markers to assess the genetic diversity and molecular fingerprints of 53 rice genotypes of O. sativa, O. glaberrima, and NERICA.ResultsIn total, 180 alleles were detected. Average polymorphism information content and Shannon's information index were 0.638 and 1.390, respectively. Population structure and neighbor-joining phylogenetic tree revealed that 53 genotypes grouped into three distinct subpopulations conforming to the original three groups, except three varieties (IR66417, WAB450-4, MZCD74), and that NERICA showed a smaller genetic distance from O. sativa genotypes (0.774) than from O. glaberrima genotypes (0.889). A molecular fingerprint map of the 53 accessions was constructed with a novel encoding method based on the SSR polymorphic alleles. Ten specific SSR markers displayed different allelic profiles between the O. glaberrima and O. sativa genotypes.ConclusionsGenetic diversity studies revealed that 50 rice types were clustered into different subpopulations whereas three genotypes were admixtures. Molecular fingerprinting and 10 specific markers were obtained to identify the 53 rice genotypes. These results can facilitate the potential utilization of sibling species in rice breeding and molecular classification of O. sativa and O. glaberrima germplasms. 相似文献
14.
李德铢 《中国科学院研究生院学报》1994,31(3):283-289
中国竹亚科分类自70年代末以来取得了长足进展，但在高山竹类的属名、种类处理，青篱竹属在中国是否存在，以及丛生竹的属级界线等问题上，国内学者间，以及国内学者与国外学者间存在不同意见。读了林万涛关于中国牡竹属的两篇文章后，认为有必要就牡竹属的范畴作一讨论，其中也涉及国内竹亚科分类的若干方法论问题。根据分支系统学的原理，“广义牡竹属”是一个单系类群。参照Clayton对属级分类阶元提出的几条原则，特别是性状的选择，讨论了椅子竹属与碟环慈竹属的归属问题。笔者认为，数量分类学并不探讨类群的起源问题，研究系统发育则需要多学科的证据，因而单从营养体个别性状的相似性来推测系统发育是不可取的。最后本文归并了椅子竹属和碟环慈竹属。 相似文献
15.
Xizang (Tibet) is rich in Leguminosae flora, comprising 41 genera and 254 species
so far known, exclusive of the commonly cultivated taxa (including 11 genera and 16
species). There are 4 endemic genera (with 8 species), 10 temperate genera (with 175
species) and 19 tropical genera (with 46 species) as well as the representatives of those
genera whose distribution centers are in East Asia-North America, Mediterranean
and Central Asia.
1. There are altogether 4 endemic genera of Leguminosae in this region. Accord-
ing to their morphological characters, systematic position and geographical distribution,
it would appear that Salweenia and Piptanthus are Tertiary paleo-endemics, while
Straceya and Cochlianths are neo-endemics. Salweenia and Piptanthus may be some
of more primitive members in the subfamily Papilionasae and their allies are largely
distributed in the southern Hemisphere. The other two genera might have been derived
from the northern temperate genus Hedysarum and the East Asian-North American
genus Apios respectively, because of their morphological resemblance. They probably
came into existanc during the uplifting of the Himalayas.
2. An analysis of temperate genera
There are twelve temperate genera of Leguminosae in the region, of which the
more important elements in composition of flora, is Astragalus, Oxytropis and Cara-
gana.
Astragalus is a cosmopolitan genus comprising 2000 species, with its center
distribution in Central Asia. 250 species, are from China so far known, in alpine zone of
Southwest and Northwest, with 70 species extending farther to the Himalayas and
Xizang Plateau.
Among them, there are 7 species (10%) common to Central Asia, 12 species (15.7%)
to Southwest China and 40 species (60%) are endemic, it indicates that the differentia-
tion of the species of the genus in the region is very active, especially in the subgenus
Pogonophace with beards in stigma. 27 species amounting to 78.5% of the total species of
the subgenus, are distributed in this region. The species in the region mainly occur in
alpine zone between altitude of 3500—300 m. above sea-level. They have developed into
a member of representative of arid and cold alpine regions.
The endemic species of Astragalus in Xizang might be formed by specialization of
the alien and native elements. It will be proved by a series of horizontal and vertical vicarism of endemic species. For example, Astragalus bomiensis and A. englerianus are
horizontal and vertical vicarism species, the former being distributed in southeast part
of Xizang and the latter in Yunnan; also A. arnoldii and A. chomutovii, the former
being an endemic on Xizang Plateau and latter in Central Asia.
The genus Oxytropis comprises 300 species which are mainly distributed in the
north temperate zone. About 100 species are from China so far known, with 40 species
extending to Himalayas and Xizang Plateau. The distribution, formation and differ-
entiation of the genus in this region are resembled to Astragalus. These two genera are
usually growing together, composing the main accompanying elements of alpine mea-
dow and steppe.
Caragana is an endemic genus in Eurasian temperate zone and one of constructive
elements of alpine bush-wood. About 100 species are from China, with 16 species in Xi-
zang. According to the elements of composition, 4 species are common to Inner Mon-
golia and Kausu, 4 species to Southwest of China, the others are endemic. This not only
indicates that the species of Caragana in Xizang is closely related to those species of
above mentioned regions, but the differentiation of the genus in the region is obviously
effected by the uplifting of Himalayas, thus leading to the formations of endemic species
reaching up to 50%.
3. An Analysis of Tropical Genera
There are 19 tropical genera in the region. They concentrate in southeast of Xizang
and southern flank of the Himalayas. All of them but Indigofera and Desmodium are
represented by a few species, especially the endemic species. Thus, it can be seen that
they are less differentiated than the temperate genera.
However, the genus Desmodium which extends from tropical southeast and northeast
Asia to Mexio is more active in differentiation than the other genera. According to Oha-
Shi,s system about the genus in 1973, the species of Desmodium distributed in Sino-Hima-
laya region mostly belong to the subgenus Dollinera and subgenus Podocarpium. The
subgenus Dollinera concentrates in both Sino-Himalaya region and Indo-China with 14
species, of which 7 species are endemic in Sino-Himalaya. They are closely related to
species of Indo-China, southern Yunnan and Assam and shows tha tthey have close con-
nections in origin and that the former might be derived from the latter.
Another subgenus extending from subtropical to temperate zone is Podocarpium.
Five out of the total eight species belonging to the subgenus are distributed in Sino-
Himalaya and three of them are endemic.
An investigation on interspecific evolutionary relationship and geographic distribu-
tion of the subgenus shows that the primary center of differentiation of Podocarpium
is in the Sino-Himalaya region.
Finally, our survey shows that owing to the uplifting of the Himalayas which has
brought about complicated geographic and climatic situations, the favorable conditions
have been provided not only for the formation of the species but also for the genus in cer-tain degree. 相似文献
16.
马金双 《中国科学院研究生院学报》1992,30(6):508-514
多药马兜钤亚属是马兜铃属目前已知3个亚属中最小的一个亚属，约9种，其中8种产于热带
非洲，1种产于热带亚洲(马来西亚)。 本工作从经典分类学角度对该亚属的系统进行了探讨，首次利用花药数目及其排列方式将其划分为三个组，并对其中所含的种类进行了分类学处理，本文承认9种及3个新异名。 相似文献
17.
中国-喜玛拉雅特有属——蓝钟花属的分类修订 总被引：2，自引：0，他引：2
Krishna K. Shrestha 《中国科学院研究生院学报》1997,35(5):396-433
Cyananthus Wallich ex Bentham, the only genus of Campanulaceae with superior ovary, is revised to clarify infrageneric relationships and phylogeny of the genus. Evidence obtained from the comparative gross morphology, anatomy, palynology, and karyomorphology recommends a new infrageneric classification of the genus, recognizing 23 species, belonging to two subgenera, four sections and four subsections. One subgenus(Subgen. Micranthus), one section(Sect. Suffruticulosi) and two subsections(Subsect. Flavi and Subsect. Lichiangenses)are described as new taxa. New combinations at sectional(Sect. Annui) and subsectional(Subsect. Stenolobi) ranks are also proposed. The genus Cyananthus is strictly distributed in the high mountains of China(Xizang, Yunnan and Sichuan), extending to Bhutan, Nepal and India(Kumaon-Garhwal, Assam and Sikkim), with altitudinal ranges from 2500～5300 m. It is observed that 13 species are endemic to SW China and only three species are endemic to the Himalayas(two species in Nepal and one to NW India). It is evident that Cyananthus is one of the most primitive genera of Campanulaceae and within the genus, subgenus Cyananthus(Sect. Stenolobi) is more primitive than the subgenus Micranthus. It is also suggested that SW China(most probably Yunnan) is the center of origin of Cyananthus, considering the occurrence of as many as 20 species of Cyananthus, representing several primitive taxa and many endemic species. 相似文献
18.