Table of Contents
  • Volume 27 Issue 4

      
      Research Articles
    • Xu Han-Qing, Huang Qing-Yuan
      1989, 27 (4): 241–246
      Observed in this paper was the development of the microspore and megaspore, male and female gametophytes in Sinojakia xylocarpa, which is endemic to China. The anther comprises four microsporangia. Microspore wall forms simultaneously after meiotic division in PMCs. The arrangment of microspore in a tetrad is tetrahedral. Bicel lular pollen grains appear at the shedding stage. ‘They are 3-colporate, with irregular min ute-faveolate exine sculpture. The anther wall development is of the dicotyledonous type, and its endothecitum develops slight fibrous thickenings, which also form on some epidermal cells. The tapetum is glandular. The pistil with hollow style is composed of three carpels, and its ovary contains several anatropous ovules. The ovule is unitegmic, tenuinucellar, but no obturator was observed. The archesporial cell functions directly as the megaspore mother cell which forms a linear tetrad, but T-shaped tetrad was found in a few ovules. A Polygonum type embryo sac forms from the functional chalazal megaspore. In the mature embryo sac, the synergids are elongate with a large vacuole at the chalazal end, but the distrihution of vacuoles in the egg cell appears random. Two polar nuclei remain in contact with each other for a spell before the fertilization and the 3 antipodal cells may persist into early postfertilzation stages. Numerous starch gra ins occur in the embryo sac. According to the present embryological studies on Sinojakia xylocarpa and the works on embryogenesis by some early embryologist, authors consider that Styracaceae, Symplocaceae, Sapotaceae and Ebenaceae are rather closely related, and we alsoconsider it reasonable to put the 4 families mentioned above in Ebenales.
    • Wang Shi-Jin, Li Jian-Hua
      1989, 27 (4): 247–256
      The flowers of the representative species of 33 tribes and 174 genera were investigated for the purpose of Gramineae systematics. Discussed in this paper are ten important flower characters, 6 of which are of the pistil, two of the androecium and two of the lodicule. The morphology of lodicules is of particularly great value in systematics, it consisting of nine forms: membranous-flattend, tongue-shaped, chaffy-peltate, hooded or helmet-shaped, spade-like, longitudinally folded, cucullate, top-shaped and funnel-thaped. Its numbers per flower may be: numerous, triple, dual, single and absent. On the basis of these ten characters, three major types and seven subtypes of the flowers of Gramineae may be recognized: Bambusoid (including True Bambusoid, Oryzoid, Arundinoid, Stipoid), pooid (with Subtype Pooid only) and Panicoid (including Eragrostoid, True Panicoid). As a result, The major groups corresponding to the flower basic types agree wih those divided according to the basic types of seedlings and caryopses. They are seven subfamilies: Banbusoideae, Oryzoideae, Arandinoi deae, Stipoideae, Pooideae, Eragrostoideae and Panicoideae.
    • Liu Yan, Hsu Ping-Sheng
      1989, 27 (4): 257–264
      The genus Lycoris (Amaryllidaceae) consists of about 20 species, all of which are confined to temperate China, Japan and Korea. Cytological investigations, including a reexamination of the karyotypes of 14 taxa, measurements of relative nuclear DNA content, and meiotic configuration observations on some specific forms and interspecific hybrids, have been carried out by the present authors in order to re-evaluate the mode of karyotype evolution and the role of hybridization in the speciation of Lycoris. These have resulted in a new theory for explaining the karyotype evolution in the genus, which will be considered elsewhere. The present paper deals with observations on karyotypes of 11 species, 1 variety and 2 artificial hybrids. Results obtained through karyotype analysis, as shown by the data in Table 1, Plates I-VI and Figs. 1-2, reveal that: (1) the karyotypes of Lycoris rosea, L. radiata var. pumila, L. sprengeri, L. haywardii, L. caldwellii, L. squamigera and L. radiata are, on the whole, consistent with those reported by the previous authors[1,2,3,4,5,8,10,12];(2) the I (rodshaped) chromosomes of L. chinensis and L. longituba are all T’s (telocentric) instead of t’s (acrocentric) or t(Sat)’s; (3) the three materials of L. aurea of different sources have shown a karyotypic differentiation: one with 2n=14=8m+6T, and the others with 2n=16=6m+10T: (4) both of the karyotypes of L. straminea and L. albiflora are 2n=19=3V+6I, inconsistent with 2n=16=6V+10I for the former and with 2n=17=5V+12I for the latter as reported by Inariyama (1953), Bose and Flory (1963) and Kurita (1987). The following aspects are worthwhile discussing: 1. The types of chromosomes. Karyotype analyses reveal the existence of three major chromosome types in Lycoris: (1) m (metacentric) chromosomes: (2) t (acrocentric) chromosomes, with short arms, (3) T (telocentric) chromosomes, sometimes with dot-like terminal centromeres. To distinghish t’s from T’s is of paramount importance for solving the problem of karyotype evolution in Lycoris. Bose (1963) pointed out that in the species with 2n=22, all I chromosomes were t’s, while in species with 2n=12-16, all I chromosomes were T’s. Our results of chromosome observations are consistent with Bose’s remarks. Some authorst[3,6] have probably mistaken the dot-like terminal centromeres of T’s of L. longituba and L. chinensis as the short arms of t’s. 2. The significance of Robertsonian change in karyotype evolution. Although chromosome numbers and karyotypes are very variable in Lycoris, as shown in Table 1, the total number of arms of a chromosome complement of any species is always multiples of 11. Hence, it seems likely that Robertsonian changes have taken part in karyotype alteration, The genus has a series of basic chromosome numbers: 6, 7, 8 and 11. But which is the most primitive one? It is uncertain whether a successive decrease in chromosome numbers as a result of Robertsonian fusion or a gradual increase in chromosome numbers brought about by fission (fragmentation) has been the essential mechanism for karyotype evolution and speciation in Lycoris. These problems are of crucial importance and will be discussed in our subsequent papers. 3. The origin of polyploids. As evident from Table 1, there are two levels of ploidy differentiation in Lycoris: (1) di ploids with 2n=22 or the equivalent of 22, (2) triploids with 2n=33 or the equivalent of 33. The most common way of origination of triploids in plants is the hybridization of diploids with Tetraploids. But tetraploids have never been found in Lycoris. Thus, it is suggested that the triploids have originated from the combination of an unreduced gamete of a diploid with a normal gamete of another diploid. 4. The role of hybridization in speciation. Results of karyotype analyses show that hybridization has taken an important part in the speciation of Lycoris. Two types of hybrids have been found: (1) 2n=19= 3V+ 16I, L. straminea, L. albiflora and the two artificial hybrids L. sprengeri×L. chinensis and L. haywardii× L. chinensis all possess this karyotype. It could be seen from the above chromosome number and karyotype that this sort of karyotype is exactly half of the total sum of 2n=22I and 2n=16= 6V+10I. It is, therefore, quite evident that taxa possessing this karyotype are all diploid hybrids of 2n=22 and 2n=16, (2) 2n=27=6V+21I, L. caldwellii and L. squamigera possess this karyotype. It is reasonable to assume, too, that they are segmental allotriploids and have arisen from the combination of an unreduced diploid gamete of 2n=16 and a normal haploid gamete of 2n=22. The origin of the hybrid karyotype 2n=17=5V+12I reported by Inari- yama (1953) is similar to that of 2n=19, except that one of the parents possesses 2n=12= 10V+2I instead of 2n=16=6V+10I. The origin of the other hybrid karyotype 2n=30=3V+ 27I reported by Bose (1963) is similar to that of 2n=27, but the diploid gamete comes from taxa possessing 2n=22 instead of 2n=16.
    • Jiang Shu-Ting, Seng Chu-Reng
      1989, 27 (4): 265–267
      The present paper reports the chromosome number and karyotype of the genus Hydrilla. H. verticillate was found to have 2n=16. The karyotype is 2n=16=6m+6sm+ 4st. No difference between the male and the female was found in the work. H. verticillata var. roxburghii Casp. has the somatic chromosome number 2n=24, and its karyotype is 2n= 3x=24=9m+9sm+6st. The variety may be a autotriploid. The karyotype of the genus isobviously bimodal, with No. 1-5 in the first group and 6-8 in the second group.
    • Chin Hui-Chen, Pan Ze-Hui, Sheh Meng-Lan, Wu Chu-Jun
      1989, 27 (4): 268–272
      This is the third report of chromosome numbers of Umbelliferae after 1981 and 1985, which deals with 24 species and varieties of 15 genera including 2 endemic genera and 10 endemic species, and most of them are distributed in southwestern China. Of them, 18 counts are newly reported. The taxonomic significance is discussed in relation with their basic numbers, translocation heterozygote and polyploids. It is considered that polyploids are wide-spread in Hydrocotyle L. 4, 6, 7, 8 are the basic numbers of Bupleurum L. which provides the cytological evidence for further study on their evolutionary process. n=9 and 10 occurrespectively in two different sections of Pimpinella L. and their basic numbers may be used for classification at the section level. The ring formation of four chromosomes at diakinesis of Heracleum henryi Wolff reveals that translocation heterozygotes is one of the factors in specific differentiation of Umbelliferae.
    • Xia Quan, Peng Ze-Xiang
      1989, 27 (4): 273–276
      Testa SEM characters of Lardizabalaceae and Sargentodoxaceae have not been used in former studies of taxonomy and phylogeny. In this work examined by scanning electron microscope (SEM). was the testa surface of 5 genera including 15 species of Lardizabalaceae and Sargentodoxaceae. Sargentodoxaceae is found quite different from Lardizabalaceae in its smooth test. The testa sculpture of Akebia, Holboellia and Stauntonia is basically striate, but that of Sinofranchetia, though striate, is verrucous on striations. Decaisnea is very isolated for its mosaic testa sculpture. The tesa examination confirms the rationality of the taxonomic treatment of Sargentodoxaceae by Stapf, the isolated taxonomic position of Decaisnea and Sinofranchetia in Lardizabalaceae, and the close interrelationship among Akebia, Holboellia, and Stauntonia.
    • Tong Shao-Quan
      1989, 27 (4): 277–292
      Twelve new species of Zingiberaceae are described from Yunnan Province, China. They are Amomum fragle S. Q. Tong, A. quadrato-laminare S. Q. Tong, A. verrucosum S. Q. Tong, A. glabrum S. Q. Tong, A. capsiciforme S. Q. Tong, A. coriandriodorum S. Q. Tong, Alpinia rubromaculata S. Q. Tong, A. emaculata S. Q. Tong, Zingiber nigrimaculatum S. Q. Tong, Hedychium glabrum S. Q. Tong, Costus viridis S. Q. Tong and Costus oblongus S. Q.Tong. A key to species of the genus Costus is given at the end of text.
    • Ma Jin-Shuang, Cheng Ching-Yung
      1989, 27 (4): 293–297
      Four new species of the genus Aristolochia (Aristolochiaceae) are described as new from China. They are Aristolochia austrochinensis C. Y. Cheng & J. S. Ma, A. caulialata C. Y. Wu, A. salweenensis C. Y. Cheng & J. S. Ma, and A. kunmingensis C. Y. Cheng &J. S. Ma. A naturalized species, A. ringens Vahl is also reported.
    • Liu Jun-Zhe
      1989, 27 (4): 298–300
      One new species and one new variety of genus Plantago are describecd from China. They are P. densiflora J. Z. Liu and P. arachnoidea var. lorata J. Z. Liu.
    • Li Chao-Luan
      1989, 27 (4): 301–303
      Malus daochengensis C. L. Li (Rosaceae) is described as new from Sichuan Province, China.
    • Shen Xian-Sheng
      1989, 27 (4): 304–305
      One new species of the genus Vitis (Vitaceae) is described from Anhui Province, China. It is vitis jinzhainensis X. S. Shen.
    • Duan Xian-Zhen, Zheng Xiu-Ju
      1989, 27 (4): 306–309
      Thirteen new varieties of the genus Fritillaria (Liliaceae) are described trom Xinjiang, China.
    • Wang Shu-Song
      1989, 27 (4): 310–316
      Anhui Province is situated in the subtropical and temperate zones. With favorable climate this district is rich in algae. During 1982-1986, the author made a number of collections of the algal specimens-about 1000 samples from 36 counties and cities of the province. The identification result shows that there are about 30 species and 15 varieties of Scenedesmus in the province. In present paper, however, reported are only some new taxa and new records of Scenedesmus. The 4 new species are Scenedesmus anhuiensis, S. huangshanensis, S. quadrialatus and S. wuhuensis, the 2 new varieties are Scenedesmus prismaticus var. spinosus and S. smithii var. spinulosus, and the 4 new records of distribution in China are Scenedesmus denticulatus var. australis Playfair, S. prismaticus Bruhl et Biswas, S. quadricauda var. dentatus Dedussand S. smithii Teiling.
Editors-in-Chief
Song Ge
Jun Wen
Impact Factor
2.779
JCR 2019 IF ranking: 56/234 (Plant Sciences, top 23.72%, Q1 quartile)
Journal Abbreviation: J Syst Evol
ISSN: 1674-4918 (Print)
1759-6831 (Online)
CN: 11-5779/Q
Frequency: Bi-monthly

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