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1.
 The present paper, mainly dealing with phytogeographical, Cytological and Palynolo gical studies on Chinese Stachyuraceae, is the first part of a series of contributions to systematics of this family. As we know, Stachyuraceae, a monogeneric family, is  endemic to East Asia, with a strong differentiation in China. Systematic position of the family is still uncertain. Undoubtedly, multidisciplinary studies on it wisl give a better understanding of plant differentiation in East-Asiatic floristic region and systematic position of the family.      The distribution of all the 9 Chinese species of Stachyurus have been studied on the basis of morphogeographical method. The status of some taxa has been changed as follows: Stachyurus chinensis Franch. ssp. latus (Li) Y. C. Tang et Y. L. Cao, stat. nov. S. chinen-sis Franch. Ssp. cuspidatus (Li) Y. C. Tang et Y. L. Cao, stat. nov. S. chinensis Franch. ssp. brachystachyus (C. Y. Wu et S. K. Chen) Y. C. Tang et Y. L. Cao, stat. nov. S. salicifolius Franch. ssp. lancifolius (C. Y. Wu) Y. C. Tang et Y. L. Cao, stat. nov., S. yunnanensis Franch. var. pedicellatus Rehd. and S. oblongifolius Wang et Tang being reduced as synonyms of S. yunnanensis Franch. From morphological point of view, we would consider that sect. Callosurus is more primitive and its present area might be the preservation center of the family.      In this paper the chromosome numbers of 5 taxa, i.e. Stachyurus yunnanensis, S. chinensis ssp. chinensis, S. chinensis ssp. cuspidatus, S. salicifolius ssp. salicifolius, S. retusus, are reported for the first time. Along with the chromosome countings of S. himalaicus and S. sigeyosii by S. kurosawa, we come to the conclusion that all the species so far studied have 24 small somatic chromosomes (2n=24).      The pollen grains of 6 taxa, i.e. Stachyurus yunnanensis, S. obovatus, S. himalaicus, S. chinensis ssp. chinensis, S. salicifolius ssp. salicifolius, S. retusus were also examined. Together with the observations of G. Erdman and Huang Tsengchien on  S. himalaicus, it seems that the pollen grains of the genus Stachyurus are rather uniform in  morphology. The pollen grains of sect. Callosurus are tricolporoidate, while those of sect. Stachyurusare tricolporate. Two pollen types, representeb by the two sections, though not strongly distinct, may be considered as further evidence of the validity of the two taxa as section.       Sexuality of flowers is also disscussed in the paper. According to our observationon six species, i.e. Stachyurus yunnanensis, S. obovatus, S. himalaicus, S. chinensis, S. salicifolius, S. retusus, the plants are dioecious, which supports T. Makino's observation on S. praecox and H. Hara's on S. himalaicus. Female flowers have relatively large pistils and short stamens with empty anthers, while male flowers have smaller sterile pistils and longer stamens with well developed anthers.  相似文献   

2.
 In the present paper, an brief historical account and the comments on the modern taxonomic systems of the genus Triticum L. are made. The author suggests that principles to determine a species be (1) a special type of genome, and (2) reproductive isolation. The principles to determine a subspecies are the special co-type of genome and incomplete reproductive isolation. There are no differences on the level of genome constitution and no reproductive isolation between the varieties or concultivars. According to these principles, the author schemes a taxonomic system of the genus Triticum L. based on biosystematics as follows:      Triticum monococcum L. sensu lat.        subsp. boeoticum (Boiss.) Yen, st. nov.           var. thaoudar (Reut ) Flaksb.           concv. Einkhorn        subsp. urartu (Tum.)Vap.      T. timopheevi Zhuk. sensu lat.           var. araraticum (Jakubz.) Yen, st. nov.      T. zhukovskyi Men. et Er.      T. turgidum L. sensu lat.           var. dicoccoides (Körn. in litt. in Schweinf.) Bowden           concv. (1) Emmer, (2) Durum wheat, (3) Rivet wheat, (4) Polish wheat, (5) Persian wheat.      T. aestivum L. sensu lat.           concv. (1) Tibetian weed wheat, (2) Spelt, (3) Vavilov wheat, (4)  Macha wheat, (5) Yunnan hulled wheat, (6) Winter common wheat, (7) Spring common wheat, (8) Branch-eared wheat, (9) Club wheat, (I0) Indian dwarf wheat, (11) Xinjiang ricewheat.  相似文献   

3.
文章报道了13种蜘蛛抱蛋属植物的染色体核型,并对属内核型进化规律作了总结。作者认为随体染色体和第1对染色体可以作为本属核型的特征染色体。染色体数目变异与花部式样密切相关。本属植物原始的染色体基数为x=19。此外,对非整倍性变异的主要机制也进行了讨论。  相似文献   

4.
 作者在调查研究云南省柴胡植物过程中,发现两个新种,定名为韭叶柴胡 Bupleurumkunmingense Y.Li et S.L.Pan 和多枝柴胡B.polyclonum Y.Li et S.L.Pan,  并进行了挥发油和皂甙成分的初步分析,发现两新种的挥发油紫外吸收光谱及薄层层析图与北柴胡B.chinense DC.的很相似; 且所含柴胡皂甙均高于北柴胡,故二者可以作为药用柴胡中的优质品而予以重视。  相似文献   

5.
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   

6.
我国悬钩子属植物的研究   总被引:1,自引:0,他引:1  
 The genus Rubus is one of the largest genera in the Rosaceae, consisting of more than 750 species in many parts of the world, of which 194 species have been recorded in China.      In the present paper the Rubus is understood in its broad sense, including all the blackberries, dewberries and raspberries, comprising the woody and herbaceous kinds. So it is botanically a polymorphic, variable and very complicated group of plants. The detailed analysis and investigation of the evolutionary trends of the main organs in this genus have indicated the passage from shrubs to herbs in an evolutionary line, although there is no obvious discontinuity of morphological characters in various taxa. From a phylogenetic point of view, the Sect. Idaeobatus Focke is the most primitive group, characterized by its shrub habit armed with sharp prickles, aciculae or setae, stipules attached to the petioles, flowers hermaphrodite and often in terminal or axill- ary inflorescences, very rarely solitary, druplets separated from receptacles. Whereas the herbaceous Sect.  Chamaemorus L. is the most advanced group, which is usually unarmed, rarely with aciculae or setae, stipules free, flowers dieocious, solitary, dru- plets adhering to the receptacles and with high  chromosome numbers  (2n = 56). Basing upon the evolutionary tendency of morphological  features,  chromosome nu- mbers of certain species recorded in literature and the distribution patterns of species, a new systematic arrangement of Chinese Rubus has been suggested by the present authors. Focke in his well-known monograph divided the species of Rubus into  12 subgenera, while in the Flora of China 8 sections of Focke were adapted, but some im- portant revisions have been made in some taxa and Sect. Dalibarda Focke has been reduced to Sect.  Cylactis Focke.  In addition, the arrangement of sections is presented in a reverse order to those of Focke’s system.  The species of Rubus in  China are classified into 8 sections with 24 subsections (tab. 3) as follows: 1. Sect. Idaeobatus, emend. Yü et Lu(11 subsect. 83 sp.); 2. Sect. Lampobatus Focke (1 sp.); 3. Sect. Rubus (1 sp.); 4. Sect. Malachobatus Focke, emend. Yü et Lu (13 subsect. 85 sp.); 5. Sect. Dalibardastrus (Focke)Yü et Lu (10 sp.); 6. Sect. Chaemaebatus Focke (5 sp.); 7. Sect. Cylactis Focke, emend. Yü et Lu (8 sp.); 8. Sect. Chamaemorus Focke (1 sp.).      In respect to the geographical distribution the genus Rubus occurs throughout the world as shown in tab. 2, particularly abundant in the Northern Hemisphere, while the greatest concentration of species appears in North America and E. Asia.  Of the more than 750 species in the world, 470 or more species (64%) distributed in North America.  It is clearly showm that the center of distribution lies in North America at present time.  There are about 200 species recorded in E. Asia, of which the species in China (194) amount to 97% of the total number. By analysis of the distribution of species in China the great majority of them inhabit the southern parts of the Yangtze River where exist the greatest number of species and endemics,  especially in south- western parts of China, namely Yunnan, Sichuan and Guizhou (tab. 3. 4.).  It is in- teresting to note that the centre of distribution of Rubus in China ranges From north- western Yunnan to south-western Sichuan (tab. 5), where the genus also reaches its highest morphological diversity.       In this region the characteristics of floristic elements of Rubus can be summarized as follows: it is very rich in composition, contaning 6 sections and 94 species, about 66% of the total number of Chinese species; there are also various complex groups, including primitive, intermediate and advanced taxa of phylogenetic importance; the proportion of endemic plants is rather high, reaching 61 species, up to 44% of the total endemics in China.  It is noteworthy to note that the most primitive Subsect. Thyrsidaei (Focke) Yü et Lu, consisting of 9 endemic species, distributed in southern slopes of the Mts. Qin Ling and Taihang Shan (Fig. 4). From the above facts we may concluded that the south-western part of China is now not only the center of distribu- tion and differentiation of Rubus in China, but it may also be the center of origin ofthis genus.  相似文献   

7.
 One new species Coloniophora shanxiensis Y. J. Ling et S. L. Xie, is described,and one new record, C. spicata (Schmid.) Islam, is reported both from shanxi, China.  相似文献   

8.
 One new genus, one new species and one new subspecies of Labiatae from Anhui and Zhejiang province of China are described and one new combina- tion is made in this paper. They are Pogonanthera H. W. Li et X. H. Guo, P. caulopteris H. W. Li et X. H. Guo, P. intermedia (C. Y. Wu et H. W. Li) H. W. Li et X. H. Guo and Paraphlomis foliata (Dunn) C. Y. Wu et H. W. Lissp. montigena X. H. Guo et S. B. Zhou.  相似文献   

9.
作者在云南发现柴胡一新种,定名为泸西柴胡Bupleurum luxiense,并以北柴胡B. chinense为对照,对其主要化学成分挥发油和皂甙进行了初步研究,发现它的地下部分含有柴胡的主要成分——柴胡皂甙a、d、c尤其是它的柴胡总皂甙含量高于北柴胡的2倍多,且资源丰富,所以是一种很有价值的药用柴胡,建议深入研究并推广应用。  相似文献   

10.
 According to Wang and Xie, their recently  published  genus  Trirostellum  is distinguished from its allied genera by a number of characteristics: (1) the stamens with their filaments coherent into a central column; (2) the female flowers possessing rudimentary stamens; (3) the ovary 3-celled, with one ovule in each cell; (4) the fruits dehiscent, 3-rostrated at the apex; (5) the fruits possessing persistent perianth; (6) the seeds tuberculate and winged.  However, upon a careful comparison of Trirostell- um yixingensis Z.P. Wang et Q. Z. Xie, the type species of Trirostellum with Gyno- stemma pentaphyllum (Thunb.) Mak., the type species of Gynostemma Bl.  and some other species of Gynostemma as well,we have found that the representatives of the above two genera are identical in most of the important diagnostic characteristics ex- cept that the fruits of the former genus are dehiscent with three long beaks at  the apex, while the fruits of the latter genus are indehiscent  with  very  short  beaks. Besides, results obtained from chromosome counting haove  shown that the somatic chromosome number of Trirostellum yixingensis is 2n=22, while that of Gynostemma pentaphyllum is 2n=28.Yet these morphological and chromosomal differences seem not sufficient for generic demarcation.  We, therefore, suggest that Trirostellum bereduced to a sectional or subgeneric rank of Gynostemma Bl.  相似文献   

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