Table of Contents
  • Volume 46 Issue 6

      
    Research Articles
    Xin-Hui ZOU; Song GE*
    2008, 46 (6): 795-807.
    With more and more sequence data available, it has been a widespread practice to apply multiple genes to reconstruct phylogenies at different hierarchical levels. The phenomenon of conflicting gene trees has accordingly become a remarkable and difficult problem. It is increasingly understood that the difference between gene tree and species tree and the causes behind should be fully appreciated in molecular phylogenetic studies. In this paper, we have explored the major causes resulting in conflicting gene trees, including stochastic errors, systematic errors and biological factors. We also introduced a newly developed discipline, phylogenomics, and demonstrated its power and great potential in resolving difficult phylogenetic problems using our recent phyloge-nomic study of Oryza as an example. Furthermore, we discussed some strategies and approaches in elucidating conflicting gene trees and provided some suggestions and recommendations for molecular phylogenetic studies using multiple genes.
    Hong-Mei LIU;,Li WANG;,Xian-Chun ZHANG,;,Hui ZENG
    2008, 46 (6): 808-829.
    Recent phylogenetic studies have revealed that the traditional concept of pteridophytes which includes lycophytes and ferns should be revised and a new classification of the extant monilophytes has just been published by Smith et al. China is very rich in plant diversity, with representatives of most important major groups of the lycophytes and monilophytes. Here we present the recent progress in phylogenetic analyses of lycophytes and monilophytes with a focus on relationships among the Chinese taxa. We conducted a phylogenetic analysis using sequence data of the chloroplast gene rbcL of 184 species (179 genera) representing 62 of a total of 63 families recognized by R. C. Ching. The relationships of all major lineages recovered in the rbcL phylogeny generally agree with those reconstructed in the studies that focused on these clades individually and had more extensive ingroup taxon sampling and/or character sampling. A tentative systematic arrangement focused on the Chinese lycophytes and monilophytes at the family level is presented.
    Fang ZHAO;,Yong-Ping YANG
    2008, 46 (6): 830-835.
    The reproductive allocation (RA, the ratio of flower biomass to total aboveground biomass) of Oxyria sinensis Hemsl., a clonal dioecious perennial, was compared among five populations along an altitudinal gradient from 1978 m to 2780 m. The goal of this study is to answer the following questions: (1) What is the variation in the reproductive allocation of O. sinensis? (2) Does variation in reproductive allocation correspond to an altitud-inal gradient? (3) Is the reproductive allocation of male and female O. sinensis correlated to environmental fac-tors? We found that reproductive allocation to ramets decreased with increasing vegetative biomass in both male and female plants. Increasing altitude corresponds to a decrease in height of ramets, total aboveground biomass, and biomass of vegetative organs in both male and female plants. The total aboveground biomass of male ramets was significantly higher than female ramets in the populations at the altitudes of 2422 m and 2780 m. The biomass of flowers and reproductive allocation of male ramets were significantly higher than of female ramets at all popu-lations except at the lowest altitude population, which indicated male ramets allocate more biomass to reproduc-tion than female ramets. Our results do not support the idea of an invariable minimum vegetative biomass for reproduction, probably because resource can be shared among ramets within one ramet system of a clonal species, and the pattern of RA in O. sinensis might be an adaptation to the unpredictable rain and decreased pollinator visitation in the higher altitudinal populations.
    14Chun-Qiu WANG; 13Yi-Bo LUO*; 2Yong-Dong TAI; 2De-Jun AN; 2Yong KOU
    2008, 46 (6): 836-846.
    Ant-plant interaction is widespread, common and diverse in terrestrial ecosystems, but ants acting as pollinators are uncommon. Here we present a study conducted in Huanglong Nature Reserve, Sichuan, China, showing that ants of Formicidae, Leptothoras sp. and Paratrechina sp., are principle pollinators of Neottia listeroides (Orchidaceae). The two ant species accounted for dominant floral visitors and transferred most pollinia in the orchid, compared to the role of other insect visitors. The flowering period of N. listeroides in the studied population lasted about 40 days, and most flowers were open from 15th to 26th July. The flower has an open nectariferous furrow on the surface of the labellum which ran down the centre to the bifurcation of the labellum, and produced the minute amount of nectar. While an ant arrived at the base of the labellum following the nectariferous furrow, it could not touch the crest of the rostellum and withdraw the pollinia until it raised its head upwards. Pollinia were often attached to the top of the ant head by the viscid fluid exuded from the touched crest of the rostellum. After being touched the rostellum bent down instantly and blocked the stigma, and then slowly recovered to its original position. The backward movement of the rostellum lasted 17–24 h (21.4±2.1 h, n=42). The temporary inaccessi-bility of the stigma decreased self-pollination resulting from revisiting of ants. Breeding system experiments showed that this orchid is self-compatible but not autogamous, and that pollination success was dependent on pollinators. The fruit set was 19.77% under natural conditions, indicating that the efficiency of this ant-pollination system is low relative to the high frequency of visitation of ants. The low pollination success of N. listeroides was considered as a result of poor match in morphology between flowers and ants. Moreover, the interaction between N. listeroides and these two ants in Huanglong Valley was suggested as a casual case in a specific period.
    Shi-Xiao LUO; Shi-Jin LI; Dian-Xiang ZHANG*
    2008, 46 (6): 847-855.
    The floral morphs of an invasive herb, Oxalis corniculata, were surveyed based on the examination of herbarium specimens deposited in IBSC, and field observation on living individuals in 24 natural populations in China. The floral phenology, pollen-ovule ratio (P/O) and floral visitors of O. corniculata were investigated and determined. Assisted pollination experiments were carried out to examine the breeding system of O. corniculata. Scanning electron microscope (SEM) and fluorescence microscope (FM) were employed to examine pollen germination and the growth of pollen tubes. The species is composed of three floral morphs in China, viz., the long-styled morph, the semi-homostyled morph, and the quasi-homostyled morph. The semi-homostyled morph is common in disturbed urban and ruderal habitats, whereas only one long-styled population was found in less disturbed habitats of Pinus forests in Anning County, Yunnan Province, although two specimens (in IBSC) of long-styled individuals collected from a same locality in Guangdong Province were also recorded. The flowering period of O. corniculata was from February to November, with a peak at March to September; the longevity of a single flower was two days, and the petals closed at the first night and reopen in the next morning. Pollen grains were found on self-stigmata, and the pollen grains were germinating on the stigmata before the flower opening. The P/O was 83.3±33.08. Nectar secretion was observed but the volume was not large enough to be measured. A small butterfly (Pseudozizeeria sp.) was observed to visit the flowers of semi-homostyled plants, but its effective-ness as a pollinator was extremely low. Fruit set of untreated bagged flowers (88.12±3.38) was not significantly different from that of open flowers (88.03±2.48). Fluorescence microscopic (FM) observations proved that pollen germinated on self-stigmata and pollen tubes grown in self-styles. Measurements of floral traits and results of manipulated pollination treatments indicated that the breeding system of semi-homostyled plants of the species is typical autogamy.
    Ai-Qin ZHANG;,Dun-Yan TAN;,Jin-Zhong ZHU
    2008, 46 (6): 856-860.
    Some control tests and a technique employing the fluorescent properties of pollen and pollen tube stained with aniline blue dye were utilized to study the stigma receptivity, the optimum pollination period, the self-pollen clogging effect, pollen germination and the pollen tube growth state in alfalfa. The results can be summarized as follows: (1) The stigma receptivity and flower longevity barely overlap. On the first day after pollination, the pollination efficiency was the highest, with a pod-seting rate per raceme of 65.17%±2.01% (P<0.01). The period of the highest pollination efficiency was the same as the peak of stigma receptivity. When pollination was on the fourth day after flowering, the pod-setting percentage per raceme was still 34.25%±6.73%. (2) Self-pollination led to a lower pollen germination frequency and a lower pollen tube growth rate than cross-pollination. When artificial cross-pollination was applied after self-pollen grains on the stigma was re-moved, the pod-setting percentage per raceme was 72.31%±6.24%, and the number of seed per pod was 3.46±0.25, In contrast, these two values were 51.76%±5.37% (P<0.01) and 2.11%±0.18 respectively (P<0.01) when the self-pollen grains were not removbed in the artificial cross-pollination experiements. Hence, the clog-ging effect of self-pollen to stigma was significant. (3) In the breeding system of alfalfa, there are two mecha-nisms that help the plants to avoid self-fertilization: dichogamy and self-incompatibility. However, due to the structure of flowers, they were not effective enough to improve cross-fertilization rate, even if the stamen matured earlier than the stigma. The typical self-incompatibility system guaranteed the lower self-fertilization rate, but cannot avoid the reproductive interference of self-pollen.
    Tao ZHANG; Dun-Yan TAN *
    2008, 46 (6): 861-873.
    The sexual system of the perennial shrub Capparis spinosa L. (Capparaceae), which is distributed in arid deserts of northern Xinjiang, was investigated. The main results can be summarized as follows. (1) The species is andromonoecious, i.e. individuals possess both male and perfect flowers. Stamens of two floral morphs are normal and can be divided into long and short ones in each flower. The perfect flowers have well developed pistils, but male flowers have aborted pistils and only function as males. (2) There were very significant differ-ences among the populations in daily ratio of the two floral morphs, number of long and short stamens of perfect flowers and length of filaments and anthers of short stamens in male flowers (P<0.01), but no significant differ-ences occurred in biomass of floral organ (P>0.05). (3) Anthesis was nocturnal and lasted 15–16 h. Both male and perfect flowers opened about 18:00 at dusk. The number of two floral morphs produced on each individual was indeterminate every day during flowering, which would make the individual temporally androdioecious. However, the total number of male flowers was more than that of perfect flowers within the population every day. (4) The P/O ratios of perfect flowers in three populations were 1.57×104, 1.65×104 and 1.71×104. There was no significant difference in pollen numbers (P>0.05) within population between male and perfect flowers or between long and short stamens, and also no significant difference among the populations in pollen numbers of male and perfect flowers, and in ovule numbers and P/O ratios of perfect flowers (P>0.05). (5) Dynamic curves of pollen viability of long and short stamens in the two floral morphs were similar in three populations. Pollen longevity of both long and short stamens was about 18–20 h, and duration of stigmatic receptivity was about 16–18 h. (6) Floral visitors were hymenopterous and lepidopterous insects. There was a total of seven species of floral visitors in the three populations. The activities of them were greatly affected by the climate of the desert environment. (7) Perfect flowers were not apomictic and could produce fruits after self-pollination (autogamy and geitonogamy) and cross-pollination; thus they had a mixed mating system. These results suggest that the sexual system of andro-monoecy may reflect an environment-heredity interaction in C. spinosa. The male flowers increase the number of pollen grains, the P/O ratio and enhance male fitness of individuals. They also increase the floral display and consequently effect cross pollination by attracting more pollinators that bring cross-pollen to the stigmas of per-fect flowers, thus increase outcrossing rate and female fitness of individuals, which insure reproductive success of C. spinosa in the extreme desert environment.
    Bao-Lin GUO*; Li-Kuan PEI; Pei-Gen XIAO
    2008, 46 (6): 874-885.
    In this paper, 129 leaf samples from 35 species and one variety of the Chinese Epimedium (Berberi-daceae), most of which were placed under subgen. Epimedium and sect. Diphyllon, were analyzed by HPLC method. The HPLC chromatogram profiles of all the samples for icariin and similar compounds were achieved, sorted and analyzed. According to the second peak group (named as “ABCI” peak group) characters, chroma-tograms were divided into four main types and nine subtypes. By correlation analysis with flower morphology, II-3 was suggested to be the most primitive type; II-1, IV and I-3 were primitive and closely related to II-3; I-1 was basic type; I-2, I-4, III and II-2 were derived types. The HPLC chromatogram type division corresponds to W. T. Stearn’s classification on sect. Diphyllon with four series in 2002.
    1Shi-Yong CHEN; 1Xiao MA; 1Xin-Quan ZHANG*; 2Zhi-Hua CHEN
    2008, 46 (6): 886-890.
    Karyotypes of ten StH-genome tetraploid in Elymus species from N. America and Asia were reported. The karyotypes belong to 1A or 2A types and their formulae are: 24m+4sm(2sat) (for E. canadensis); 20m+8sm(4sat) (E. elymoides); 20m+8sm(4sat) (E. glaucus); 22m+6sm(4sat) (E. lanceolatus); 22m+6sm(2sat) (E. mutabilis); 22m+6sm(2sat) (E. sibiricus); 24m+4sm (E. trachycaulus); 22m+4sm+2st(2sat) (E. trachycaulus ssp. subsecundus); 24m+4sm(4sat) (E. virginicus); and 20m+8sm(4sat) (E. wawawaiensis).
    1Jia-Xi LIU; 2Yi-Zhen XI*; 2Yu-Long ZHANG; 2Jian-Chang NING; 1Xiao-Rui LIU
    2008, 46 (6): 891-898.
    In order to study the taxonomy of Boraginaceae further, pollen morphology of six species in Heliotro-pium, two species in Messerschmidia, and one species in Tournefortia from the subfamily Heliotropioideae was examined by light and scanning electron microscopy. Pollen grains are prolate. They are elliptic from the equato-rial view, and 6-lobate circular, 8-lobate circular or rarely triangular from the polar view. There are three aperture types in the subfamily Heliotropioideae, namely: (1) 3-colporate alternated with 3-pseudocolpate type, (2) 4-colporate alternated with 4-pseudocolpate type, and (3) 3-colporate type. The exine surface is faintly perforated, rugous decorative, or rarely psilate. The results showed that the three genera in the subfamily Heliotropioideae of Boraginaceae are closely related. Based on pollen features, the genus Tournefortia might be basal in Helio-tropioideae of Boraginaceae. Heliotropium seems to represent a more derived lineage than both Tournefortia and Messerschmidia, and the genus Messerschmidia lies between Heliotropium and Tournefortia. Pollen morphologi-cal features suggested that the subfamily Heliotropioideae is a transitional type from Ehretioideae to Boragi-noideae. Pollen grains in the genus Tournefortia of the Heliotropioideae are of 3-colporate aperture, implying a possible close relationship between Heliotropioideae and Cordioideae.
    13Li-Xia GAO; 1Xiu HU; 2Nian LIU*; 3Bang-Hai HUANG; 4Zheng-Jun LI; 4Yan LI
    2008, 46 (6): 899-905.
    The traditional taxonomy of Hedychium was based on the bracts arrangement, imbricate or tubular, and this genus was divided into two subgenera. However, that was queried in recent years. The phylogenetic relationship of a total of 22 samples representing 19 species and 1 variety of Hedychium was investigated using SRAP technique. SRAP analysis produced 152 bands by using the 28 most informative primer pairs, 135 (88.8%) of which were polymorphic. Clustering analysis indicated that: (1) Hedychium from China can be divided into three groups. Plants in group I are short and distributed in limestone. Plants in group II are tall and seldom distrib-uted in limestone. Plants in group III are with only one flower per bract, while plants in other two groups are with two or more flowers per bract. This result supports Wood’s subdivision based on internal transcribed spacer sequence. (2) Wu’s treatment by reducing H. emeiense Z. Y. Zhu to be a synonym of H. flavescens is supported. (3) H. flavum Roxb. and H. panzhuum Z. Y. Zhu are shown to be the same species, and H. panzhuum is reduced to be a synonym of H. flavum (4) The edaphic conditions are believed to be very important for the adaptation and evolution of Hedychium. In this paper, it is suggested that Hedychium be divided into two groups according to the number of flowers per bract.
    Quan-Ru LIU;,Guan-Hua MING;,Yuan GE;,Xian-Chun ZHANG
    2008, 46 (6): 906-915.
    A taxonomic revision of the genus Lepisorus sect. Hymenophyton Ching ex S. L. Yu & Y. X. Lin from China was made. Rhizome scales and paraphyses were found to be important characters for sectional de-limitation and species identification. Sixteen species recorded in Flora Reipublicae Popularis Sinicae are reduced into five species, namely L. albertii, L. thaipaiensis, L. likiangensis, L. crassipes, and L. clathratus. SPSS statisti-cal analysis of the rhizome scales also indicated that the 16 species could be grouped into five distinct groups.
    Wei-Bin XU;, Yong-Yan LIANG;,Xian-Chun ZHANG;,Yan LIU
    2008, 46 (6): 916-918.
    Caobangia A. R. Smith & X. C. Zhang, originally described from northern Vietnam, was recently collected from southwestern Guangxi, China. The genus is similar to Lepidogrammitis, Lepisorus and Lem-maphyllum, but differs by having long-creeping filiform rhizomes with clathrate rhizome scales, monomorphic to subdimorphic simple blades with dense acicular scales. Caobangia is a monotypic genus, with only one species, namely C. squamata A. R. Smith & X. C. Zhang, which at present is only found in Caobang Province of northern Vietnam and southwestern Guangxi of China. According to the original literature and specimens from Guangxi, the characteristics of this monotypic genus are described, and habitat photos of C. squamata are also provided.
    12Xiao-Mei WEI; 1Xin-Fen GAO*; 13Li-Bing ZHANG*
    2008, 46 (6): 919-928.
    The Rosa sericea complex contains R. omeiensis, R. sericea and R. mairei. They are morphologically similar to one another and the systematic status of R. omeiensis has been controversial. In this study we examined ca. 2000 herbarium specimens of the three taxa in major herbaria in China and conducted field observations in Sichuan and Yunnan. We also performed SEM study of pollen morphology and seed coat structure. We further carried out intensive morphometric study on the leaflet, pollen, and seed morphology. Our results showed that R. mairei can safely be distinguished from other two, while there are no obvious discontinuities in pollen morphol-ogy, seed coat structure and plant morphology in general for R. omeiensis and R. sericea. Nevertheless, in most cases R. omeiensis and R. sericea can be distinguished from each other to some extent. They also have different geographical distributions. Therefore we here sink R. omeiensis to be a variety of R. sericea. Six forms related with these two taxa are synonymized. The four synonyms of R. sericea var. sericea include R. omeiensis f. glan-dulosa T. T. Yu & T. C. Ku, R. omeiensis f. pteracantha Rehder & E. H. Wilson, R. sericea f. glabrescens Franchet, and R. sericea f. pteracantha Franchet, while two synonyms of R. sericea var. omeiensis include R. omeiensis f. paucijuga T. T. Yu & T. C. Ku and R. sericea f. glandulosa T. T. Yu & T. C. Ku. Detailed morpho-logical descriptions and geographical distributions of the three taxa are given.
    1Jian-Lin LIU*; 2Yu TANG*; 1Ming-Zhong XIA; 3Ji-Rong SHAO*; 1Guang-Ze CAI; 1Qiang LUO; 2Jun-Xiu SUN
    2008, 46 (6): 929-932.
    Fagopyrum crispatifolium J. L. Liu, a new species of the Polygonaceae from Luojishan, Puge, Si-chuan Province, China, is described. This species is closely related to F. gracilipes (Hemsl.) Damm. & Diels, but differs in having leaf blade bullate on the surface, margin corrugated with irregular sinuous-crenate, crenate or crenellate, cyme conferted. It is tetraploid with 2n=4x=32.
    12Hai-Sang LIU*; 1Ci-Quan LIU
    2008, 46 (6): 933-937.
    Based on the lectotypes of Araucaria cunninghamii and A. heterophylla, the status of those species as cited in Chinese taxonomic literature, such as Flora of Guangzhou, Dendrology of China, Iconographia Cormo-phytorum Sinicorum, Flora Reipublicae Popularis Sinicae, Sylva Sinica, Flora of China and Higher Plants of China, was reviewed. Araucaria heterophylla has linear, acute juvenile leaves held at an angle of less than 45° to the branchlet and without an obvious adaxial keel and scale-like adult leaves on terminal branchlets; A. cunning-hamii has bilaterally compressed, subulate, shortly pungent juvenile leaves held at an angle of 45°–90° and with an obvious keel on both surfaces and tetragonous, subulate adult leaves on terminal branchlets. The names A. cunninghamii and A. heterophylla have been misapplied in Chinese taxonomic literature and should be A. hetero-phylla (Salisb.) Franco and A. cunninghamii Aiton ex A. Cunn. respectively.
Editors-in-Chief
Song Ge
Jun Wen
Impact Factor
4.040
JCR 2018 IF ranking: 22/228 (Plant Sciences, top 9.4%, 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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