Table of Contents

10 September 2010, Volume 48 Issue 5
Cover illustration: Flower morphology of Tengia. A, The plant with infl orescence and fl owers at anthesis. B, The nearly closed corolla with a keyhole opening from which the stigma is exserted. C, Five equal and fertile stamens. D, Floral diagram. See PANG et al., pp. 309–317 in this issue.
    Research Articles
  • Hong-Bo PANG, Qing-Wen SUN,Shun-Zhi HE,Yin-Zheng WANG﹡
    J Syst Evol. 2010, 48(5): 309-317.
    Tengia has been called a “natural peloria” in the family Gesneriaceae because it exhibits an almost perfect actinomorphic flower from whorl one to whorl three. It would be especially interesting to know whether or how CYC-like gene activities are related to this type of perfect actinomorphic flowers. To address this, we have isolated four CYC-like TCP genes and conducted an investigation on their expression patterns in Tengia. TsCYC1C and TsCYC1D have similar expression patterns with strong signals being detected in all five petals and stamens, while TsCYC2A and TsCYC2B are only transiently expressed in the very early floral meristem. Our results suggest that the expansion of the expressions of TsCYC1C and TsCYC1D from the dorsal to the ventral petals is likely responsible for the evolutionary formation of the fully dorsalized actinomorphic corolla, i.e., an expanded functional domain of CYC-like gene dorsal identity in Tengia corolla. However, the expressions of TsCYC1C and TsCYC1D are not correlated with stamen abortion, that is, TsCYC genes do not functionally repress the stamen development in Tengia flowers, which is probably due to changed cis-activities that results in the cell cycle-related genes uncoupling from the TsCYC regulatory pathway in Tengia.
  • Hong-Chun ZHENG* Sheng-Wen MA Tuan-Yao CHAI
    J Syst Evol. 2010, 48(5): 318-325.
    Phytolacca is the most original and biggest genus in Phytolaccaceae and one special genus in plant systematic studies as well. The light microscopy observation results show that Ph. americana L. ovule arises from caulis (floral receptacle). The perisperm and hypostase are initiated from the top several layers cells of chalaza simultaneously after fertilizing, and the perisperm is located between nucellus and hypostase. The hypostase cells are thin-walled with dense cytoplasm, clear nuclear, and some reserve granules in earlier stage, and change to thick-walled and dead cells at heart-shaped embryo stage. Its main function may maintain the cellular division and perisperm growth without delivering nutrient materials to perisperm. Furthermore, an evolutionary picture of placentation in Caryophyllales is presented by authors in the paper.
  • Xin WANG
    J Syst Evol. 2010, 48(5): 326-335.
    The origin of angiosperms has been a focus of intensive research for a long time. The so-called pre-Cretaceous angiosperms, including Schmeissneria, are usually clouded with doubt. To expel the cloud around the enigmatic Schmeissneria, the syntype and new materials of Schmeissneria collected previously in Germany and recently in China are studied. These materials include female inflorescences and infructescences. The latter are old materials but were under-studied previously. Light microscopy and SEM observations indicate that the fruits in these infructescences have in situ seeds enclosed, and that the ovaries are closed long before pollination. Thus the plants meet two strict criteria for angiosperms (angiospermy plus angio-ovuly). Placing Schmeissneria in angiosperms will extend the record of angiosperms up to the Early Jurassic, more compatible with many molecular dating conclusions on the age of angiosperms, and demanding a reassessment of the current doctrines on the origin of angiosperms. Although the phylogenetic relationship of Schmeissneria to other angiosperms apparently is still an open question, this study adds to research concerning the origin of angiosperms.
  • Abiodun Emmanuel AYODELE Zhe-Kun ZHOU*
    J Syst Evol. 2010, 48(5): 336-343.
    The fruit morphology of 18 taxa representing seven genera of the family Polygonaceae in West Africa was investigated using Scanning Electron Microscopy. The achenes are trigonous, lenticular, globose, subglobose, heart shaped, ovoid or cone like. Sizes range from 0.12 x 0.10 cm2 in Polygonum plebeium to 7.87 x 0.58 cm2 in Afrobrunnichia erecta. Colours are brown to black. The cells are isodiametric in Polygonum plebeium, irregular in Afrobrunnichia erecta, Antigonon leptopus, Harpagocarpus snowdenii and polygonal in other species. The walls are straight, curved, or undulate and are either raised or depressed. A. erecta is characterized with deeply sinuate lateral walls. Cell surface may be smooth or tuberculate or fibrillate in the family, usually covered with wax deposits. The combination of these characters is mainly taxonomically useful at the tribal level and rarely at the specific or infra specific level for the delimitation of the taxa.
  • Fei YU, W. John KRESS,Jiang-Yun GAO
    J Syst Evol. 2010, 48(5): 344-349.
    Polyploidy is a major mechanism of adaptation and speciation in plants. Two varieties of Hedychium villosum, var. villosum and var. tenuiflorum, primarily differ in plant and flower size. Chromosome number suggests that var. tenuiflorum is diploid (2n=34) and var. villosum is tetraploid (2n=68). Although the flowers of the two varieties do not have any difference in floral shape, each can be easily distinguished morphologically because the shoots, leaves and flowers of the tetraploid var. villosum are consistently larger than the diploid var. tenuiflorum. The two varieties each possess distinct geographic ranges and habitats, and no sympatric distribution has been found. The tetraploid var. villosum has a broader geographic distribution range and more diverse ecological habitats than the diploid var. tenuiflorum. The two varieties are also completely reproductively isolated due to the non-overlap of the their flowering times. The two varieties should be recognized as two distinct species as they fulfill the requirements of various species concepts. Thus, we suggested that the tetraploid var. villosum should be kept as Hedychium villosum and the diploid var. tenuiflorum should be renewed to Hedychium tenuiflorum.
  • Li-Jun CHEN, ,Zhong-Jian LIU, You-Yu LI, Li-Qiang LI
    J Syst Evol. 2010, 48(5): 350-355.
    A new Paphiopedilum entity found in southern Guangdong was studied taxonomically by means of nrITS analysis in addition to morphological and phytogeographical considerations. This entity is similar to P. gratrixianum (Masters) Rolfe morphologically, from which it differs by having narrower leaves not wider than 2 cm and lacking purple spots toward abaxial base, pale green dorsal sepal veined with pale purplish brown and not heavily spotted with purple, and staminode subtruncate and mucronate at apex. An analysis of ITS sequences of this entity and its allies came to the same conclusion that the entity is a member of Paphiopedilum section Paphiopedilum and closely related to but distinct from P. gratrixianum. As a result, it is treated here as a new species: P. guangdongense Z.J. Liu & L.J. Chen.
  • Miao SUN,Qi LIN
    J Syst Evol. 2010, 48(5): 356-390.
    A revision of Elaeagnus L. for mainland China is provided based on field observations and herbarium studies. 42 morphological characters are selected and coded, and then the matrix is prepared following cluster analysis with Statistica v.8.0. Morphological characters and species delimitation are re-evaluated resulting in the recognition of 36 species, one subspecies and five varieties in mainland China. 13 species names and three variety names are regarded as new synonyms. Species information covers full synonyms, type information, description, taxonomic remarks, distribution range, occupied habitats, examined specimens, relevant illustrations, and reference to selected published illustrations and literatures. Key for whole species determination is provided. The lectotypification of E. magna (Serv.) Rehd. has been designated.