J Syst Evol

Chloroplast matK gene phylogeny of Taxaceae and Cephalotaxaceae, with additional reference to the systematic position of Nageia

WANG Xiao-Quan, SHU Yan-Qun

J Syst Evol. 2000, 38(3): 201-210.

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Reported in the present paper is a robust chloroplast matK gene phylogeny of Taxaceae, Cephalotaxaceae and Podocarpaceae represented by 10 species of seven genera, with three species of the Pinaceae as outgroups. The matk length of the 13 species ranges from 1488 bp to 1548 bp, which results from indels, in particular, 1-bp(base pair) insertion near the 3’ end of the gene in some groups. A 27 bp deletion was found at the nucleotide position 213 from the 5’ end of the matk gene of Pseudotaxus chienii. The aligned sequences used in PAUP and MEGA analyses were 1568 bp and 1494 bp respectively. In the matK gene, the rates of variation at the first, second and third codon positions are similar although the mean frequency of synonymous substitution is approximately twice as high as that of nonsynonymous substitution. Branch-and-Bound search found only one most parsimonious tree (tree length = 895, CI = 0.850, RI = 0. 876), in which all clades were strongly supported by bootstrap test. According to the tree, Taxaceae and Cephalotaxaceae are monophyletic groups, and the sister group relationship between the two families was confirmed. Taxus is closely related to Pseudotaxus while Torreya is the sister group of Amentotaxus. In addition, the close relationship between Nageia and Podocarpus was resolved. The present study supports the generic status of Pseudotaxus and Amentotaxus in point of cladistic analysis and genetic distance, but contra-dicts the establishment of the family Nageiaceae.

Evolution of Internal Transcribed Spacer Region of Nuclear Ribosomal DNA in Allopolyploids of Aegilops

WANG Chao, WANG Jian-Bo, SHI Su-Hua, ZHONG Yang

J Syst Evol. 2000, 38(3): 211-217.

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Hybridization with subsequent polyploidy is a prominent process in evolution of higher plants, but few data address the evolution of homeologous sequences after polyploidy. The internal transcribed spacer (ITS) of nuclear ribosomal DNA (nrDNA) from eleven allopolyploid species in Aegilops was investigated by PCR amplification and direct sequencing. The sequences obtained were used to study the evolution of ITS region in allopolyploid species. The length of ITS region varied from 599 to 606 bp and the number of variable sites was 93, i.e. 51 and 42 for ITS1 and ITS2 re spectively. Some polymorphic sites were observed in polyploid species, and this indicated that the ancestral sequences had not been homogenized completely by concerted evolution. Distance matrix analysis of diploid and polyploid species by neighbor-joining method, using Triticum monococcum as outgroup, resulted in well-resolved neighbor-joining tree indicating that the ITS regions of UUMM and UUSS genome ( sect. Vertebrata) were homogenizing toward those of UU ancestal genome. This result is in agreement with the results of ctyogenetics of Aegilops. On the other hand, the neighbor joining tree including the D-genome group species (sect. Cylindropyrum and sect. Polyeides ) com prised three clades (CC-DDCC, UU-DDMM-DDMMSS-DDMMUU and MM-DDMvMv), which sug gested that concerted evolution was homogenizing the ITS region of the polyploid derivatives to either of their ancestors.

Comparative studies on leaf structure and oil cells of the Magnoliaceae in China

CAI Xia, HU Zheng-Hai

J Syst Evol. 2000, 38(3): 218-230.

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The leaf structure and morphology, the structure and location of oil cells in leaves of 82 species and 1 subspecies in 10 genera of the Magnoliaceae were comparatively studied using tissue clearing, paraffin sectioning and thin sectioning. In leaves of Liriodendroideae, some of abaxial epidermal cells are papillose and the vascular tissue of the main vein appeared to be separated. However, papillose cells were not found and there were uniseriate, multicellular or unicellular hairs distributed on the epiderm, and the vascular tissue of the main vein appeared to be continuous in leaves of the Magnolioideae. Furthermore, in the Magnolioideae, the structure of leaves of Manglietia were different from that of Magnolia. These results support the separation of Magnolioideae and Liriodendroideae, and suggest that Manglietia and Magnolia be independent genera, which is consistent with Law’ s taxonomic scheme. Oil cells are one of marked features of the leaf anatomy of the Magnoliaceae, and they are mainly distributed in the palisade tissue in leaves of 47 species and in the spongy tissue in leaves of 5 species, and dispersed in the whole mesophyll in leaves of 31 species. The size and location of oil cells in leaves, combined with the thickness of leaves, the number of layers of the palisade tissue, the ratio of palisade tissue to spongy tissue in thickness, the hypo-derm, and the type of hairs may be used as the characteristics of genera and even species.

The growth pattern of shoots in Whytockia (Gesneriaceae) with phylogenetic implications

WANG Yin-Zheng

J Syst Evol. 2000, 38(3): 231-235.

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The morphogenesis of shoots in Whytockia W. W. Smith was investigated in order to reveal its growth pattern. The shoot in Whytockia has lost apical growth, which is contrary to the present knowledge about its growth pattern. Its stem is in fact a lateral branch system formed by sprouting of lateral buds in axils of small leaves substituting for the thoroughly restrained phyllogens. The unbranched stem of the genus is due to the restrained state of axillary buds in axils of large leaves. This so-called simple stem is secondary in phylogeny rather than relict in Epithemateae. According to the revealed growth pattern of the shoot in Whytockia, the present paper discusses the phylogenetic relationships between Whytockia and Loxonia, Monophyllaea and Rhynchoglossum in Epi-themateae.

Systematic position of Nannoglottis Maxim. s.l. (Asteraceae): karyomorphological data

LIU Jian-Quan, HO Ting-Nong, LIU Shang-Wu

J Syst Evol. 2000, 38(3): 236-241.

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This paper describes for the first time the karyomorphology of 4 populations of 2 species of Nannoglottis Maxim. s. l. The two species both show the resting nuclei of the complex chromocenter type and the mitotic prophase chromosomes of the interstitial type. The karyotype formula of N. gynura is 2n = 18 = 14m + 2sm + 2st(SAT) in two populations while that of N. carpesioides is 2n = 18 = 14m + 2sm(2SAT) + 2st in two populations. The two species under study represent two sections of Nannoglottis s. l. N. gynura, the only species of sect. Stenolepis, is considered as the most primitive member of the genus. Accordingly, the basic chromosome number of the genus might be x＝9. Karyomorphological data indicate that Nannoglottis should be placed in the tribe Astereaerather than in the Inuleae and the Senecioneae.

A subspecific taxonomic study on Asplenium trichomanes L. from China

HOU Xin, WANG Zhong-Ren

J Syst Evol. 2000, 38(3): 242-255.

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With the evidence from palynological, cytological, ecological and morphological data, the subspecific taxonomy of Asplenium trichomanes L. from China is carried out. Four subspecies and one variety, i.e.A. trichomanes L. ssp. trichomanes, A. trichomanes L. ssp. inexpectans Lovis, A. trichomanes L. ssp. quadrivalens D. E. Meyer emend. Lovis, A. trichomanes L. ssp. pachyrachis (Christ) Lovis et Reichst. and A. trichomanes L. var. harovii Moore emend. Midle are recognized from China. The distribution of each subspecies and variety is also presented. Some fragments of a type specimen named as A. trichomanes L. var. centrochinense Christ in PE are found to be different from the known taxa of A. trichomanes L. complex both morphologically andcytologically, and therefore are regarded representing a new species.

A revision of Chinese Thuidiaceae (s. l., Musci)

WU Pan-Cheng, JIA Yu

J Syst Evol. 2000, 38(3): 256-265.

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The study on Chinese Thuidiaceae was started in 19th century. However the present paper deals with the first revision of the family in China. There are 17 genera and 71 species in total including one subspecies. In this paper, several nomenclatural problems are treated, mainly involving 7 genera: Leptocladium Broth., Anomodon Hook. et Tayl., Haplocladium ( C. Muell. ) C. Muell., Claopodium (Lesq. et Jam. ) Ren. et Card., Bryonoguchia Iwatsuki et Inoue, Helodium (Sull.)Warnst. and Actinothuidium (Besch.)Broth. One new species, 3 new synonyms, includingone generic synonym and two specific synonyms, and one Chinese new name are reported.

The reclassification of Lycopodiaceae (s. str.) in China

ZHANG Li-Bing, KUNG Hsian-Shiu

J Syst Evol. 2000, 38(3): 266-275.

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The fern-allied family Lycopodiaceae(s. str. ) in China is reclassified in the present paper. Six genera, fifteen species and three forms are recorded. The genus Pseudolycopodiella Holub (1983) is adopted, one new name, Lycopodium neopungens H. S. Kung et L. B. Zhang, is given to replace the invalid name L. pungens Desv., one new form is described: Palhinhaea hainanensis C. Y. Yang f. glabra H. S. Kung et L. B. Zhang, and nine names are treated for the first time as synonyms: L. annotinum L. var. brevifolium Christ( = L. zonatum Ching), L. annotinum L. var. aciculare Christ( = L. zonatum Ching), L. alticola Ching( = L. zonatum Ching), L. simulans Ching et H. S. Kung ex Ching( = L. japonicum Thunb. ex Murray), L. interjectum Ching et H. S. Kung ex Ching( = L. japonicum Thunb. ex Murray), L. taliense Ching(＝L. japonicum Thunb. ex Murray), L. pseudoclavatum Ching( = L. japonicm Thunb. ex Murray.), L. pseudoclavatum Ching var. yunnanense Ching( = L. japonicum Thunb. ex Murray), and L. centro-chinense Ching( = L. japonicum Thunb. ex Murray). The distribution of all the taxa is also given. Additionally, some taxonomic discussions are made and it is considered that there is no Diphasiastrum wightianum (Wall. ex Grev. et Hook. ) Holub( = Lycopodium wightianum Wall. ex Grev.et Hook. ) in the flora.

Notes on species of some genera of Rosaceae, China

LU Ling-Ti

J Syst Evol. 2000, 38(3): 276-281.

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In the course of preparing an account of some genera in the Rosaceae for the Flora of China, some species have been taxonomically revised based on herbarium materials( particularly type specimens), and on the literature concerned. Some new combinations have been made and two vari-eties have been described as new.

A new subspecies of the genus Lasianthus Jack (Rubiaceae) from Yunnan with reference to its biogeographical implication

ZHU Hua, WANG Hong, LI Bao-Gui

J Syst Evol. 2000, 38(3): 282-285.

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New taxa of Ligularia (Compositae) from China

LIU Shang-Wu, HO Ting-Nong

J Syst Evol. 2000, 38(3): 286-288.

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Three new species of Elaeagnus (Elaeagnaceae) from Guangxi, China

FANG Ding, LIANG Ding-Ren