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The current problems being studied by different authors of the evolution of angiosperms are reviewed in general. An analysis of the arguments on principles and methodology of the system of plant classification have been made.  We support the views put forward by the phylogenetic school and hold that phylogeny should be taken as the guiding principles upon which the classificational system of angiosperms should be built and as the ultimate aim of taxonomy. We disagree with the views of the phenetic school.  The course of evolution is a unity of the process of the origin and the development in its history and the process of dispersal of angiopserms on earth.  The contradiction of variability and heredity is the driving force in the evolu- tion of angiopserms, nay, of all organisms.      In the methodology we suggest that comparative analysis should ge hand in hand with the experimental synthesis.  In essence, the classification based on overall simi- larities or most numbers of attributes to determine the relationships between various groups of angi osperms is the deductive inference of formal logic. For the elucidation of the laws of the origin and development of angiosperms the method of analysis and synthesis of the dialectical logic should be adopted.      The progress of studies achieved in the origin and  angiopserms of particularly monocotyledons has been summarized, and the common points and discrepancies of the authors have also been pointed out. The tendency of further development in the stud- ies of the origin of angiosperms has been estimated.  All  branches  of botany  have acumulated a large amount of data.  Since 1960 some significant works have been done, especially on the origin and early evolution of angiosperms, which has been being the central problem of more intensive study challenging all botanist of different dis- ciplines today.      The review is concluded with a proposal that in order to do further research on the origin and early evolution of angiopserms, all branches of botany must cooperate, and main attention should be paid to the important groups which may play a key rolein the development of plant life on earth.  相似文献   
2.
 In the present paper, the somatic chromosome numbers of 2 varieties of Actinidia chinensis Planch. are counted as follows: A. chinensis var. chinensis 2n=58(2x), A. chinensis var. hispida 2n=ca. 174(6x).  Both numbers are reported for the first timefor the species.  相似文献   
3.
马尾树科的形态及分类系统位置的讨论   总被引:1,自引:0,他引:1  
 The present paper is devoted to a study of the basic morphological and anatomical characteristics of the endemic family Rhoipteleaceae from China.  The fundamental pattern of the morphological and anatomical characteristics of the Rhoipteleaceae is similar to those of the Juglandaceae in wood anatomy, resinous peltate scales, apetaly, bicarpellate pistils, one-seeded fruits and exalbuminous seeds.  Whereas Rhoipteleaceae has stipules; perfect flowers with superior 2-loculed ovaries, anatropous ovules and two integuments; vessel elements of the secondary xylem with the scalariform perforation, and 2–8 (18) pores on the oblique plate being observable; vascular rays heterocellular and tricolporate pollen.  The above characteristics–at least most of them, agree pretty well with those depicted by Manning in his “Pre-Juglandaceae”.  It is quite possible that the Juglandaceae is derived from  “Pre-Juglandaceae”by  way  of the Rhoipteleaceae, as the morphological and anatomical features as indicated above tend to show that the Rhoipteleaceae is more primitive than Juglandaceae.      The Rhoipteleaceae was previously considered  as related  to  the Betulaceae or Ulmaceae, a view, which the present study does not prove to be acceptable. Both Takh- tajan (1969) and Cronquist (1968) pointed out that the Juglandales, Urticales, Myrica- les, Fagales are all direct derivatives from the Hamamelidales.  However, since the Rhoipteleaceae is simillar to the Betulaceae in wood anatomy and pollen, it seems that there too could have certain relationships between the Rhoipteleaceae and the Betula-ceae in the course of evolution.  相似文献   
4.
1.  The present paper describes the observations of chromosome  numbers  and karyomorphology of 2 species of 2 endemic genera and I endemic species of Chinese Ranunculaceae: Asteropyrum peltatum (Franch.)  Drumm et Hutch. 2n=16, x=8; Kingdonia unifolia Balf. f. et W. W. Sm. 2n=18, x=9 and Calathodes oxycarpa Spra- gue 2n=16, x=8.  The chromosome counts of three ranunculaceous genera are repor- ted for the first time.       2.  The morphylogical, palynological and cytological date in relation to the syste- matic postition of Asteropyrum, Kingdonia and Calathodes within the family Ranun- culaceae are diseussed and resulted in following conclusions:       (1).  On the basis of the basic number x=8 in Asteropyrum, it is further con- firmed that this genus is distinct from the r elated genera such as Isopyrum, Dichocarp- um and other allied taxa.       The comparison of Asteropyrum with Coptis shows that they are identical in short chromosomes, with magnoflorina and benzylisaquinodine type of alkaloides, but dif- ferent from coptis in the chromosome numbers (T-type), pantocolpate pollens, united carpels and the dorsi-ventral type of petioles.  In view of these fundamental morpho- logical and cytological differences, Asterop yrum is better raised to the level of Tribe. However Asteropyrum and Coptis may represent two divaricate evolutional lines of Thalictroideae.       (2).  The systematic position of the genus Kingdonia has been much disputed in the past.  We support the view of Sinnote (1914), namely, the trilacunar in leaf traces “the ancient type”, appeared in the angiosperm line very early, while the uni- lacunar of Kingdonia may be derived from the trilacunar.  On the basis of the chromo- some numbers and morphylogical observation, the present writer accept Tamura’s and Wang’s treatment by keeping Kingdonia in Ranunculaceae instead of raising it to a family rank as has been been done by Forster  (1961).  Kingdonia and  Coptis are similar in having short chromosome with x=9, but with one-seeded fruits; therefore it is suggested that placed into Thalictroideae as an independent tribe, indicating its close relationship with Coptideae.        (3).  Comparing with its allies, Calathodes being with out petals, seems to be more  primitive than Trollius. But Calathodes differs from Trollius with R-type chromosomes in having T-type chromosome with x=8 and subterminal centromere.  Those charac- teristics show that it is very similar to the related genera of Thalictroideae.  But as Kurita already pointed out that most speci es of Ranunculus have usually large long chromosomes but some species have compar ativelly short chromosomes, therefore we regard T-type and R-type chromosomes appear independently in different subfamilies of Ranunculaceae. According to Tamura, G alathodes seems to be  closely related  to Megaleranthis, because of the resemblance in follicles.  But due to lack of cytological data of the latter genus, the relationship between the two genera still is not clear pen- ding further studies. From the fact that the  morphology and  chromosomes  of  the Calathodes differs from that of all other genera of the Helleboroideae, we consider Calathodes may form an independent tribe of its own with a closer relationship withTrollieae.  相似文献   
5.
杜仲科的解剖学和胚胎学及其系统关系   总被引:1,自引:0,他引:1  
本文作者用光学显微镜对杜仲科Eucommiaceae的木材解剖和胚胎发育过程进行了观 察,并与榆科Ulmaceae和金缕梅科Hamamelidaceae进行了对比分析。  根据木材和胚胎学的资料,并结合外部形态和化学方面的资料,讨论了杜仲科的分类系统位置。  相似文献   
6.
中国茄科天仙子亚族的花粉形态研究   总被引:1,自引:0,他引:1  
本文作者对国产茄科天仙子亚族6个属、12种植物的花粉,用光学显微镜、扫描电镜和 透射电镜观察了它们外壁雕纹、萌发孔的类型以及外壁层次的结构。  本亚族花粉以无萌发孔 和三孔沟类型为主,其次为三沟和拟沟类型。根据花粉资料,表明花粉形态特征对于论证该亚族内属的界限和属间系统发育的关系,可以提供重要的依据。  相似文献   
7.
猕猴桃科的花粉形态及其系统位置的探讨   总被引:3,自引:0,他引:3  
本文作者用光学显微镜和扫描电镜(少数种类用透射电镜)对猕猴桃科Actinidia-     ceae(按照Cronquist 1981和Dahlgren 1983的概念)的猕猴桃属Actinidia(15种)、藤山柳     属Clematoclethra(5种)和水东哥属Saurauia(3种)植物的花粉形态进行了观察,并与山茶科     Theaceae(7属9种)和山柳科Clethraceae(1属1种)的花粉进行了对比分析。根据花粉的     资料,并综合分析有关的外部形态、胚胎和化学方面的特征,讨论了猕猴桃科的范围,以及这个 科的系统位置。  相似文献   
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