Li J.-H.,CAS Institute of Botany |
Li J.-H.,University of Chinese Academy of Sciences |
Liu Z.-J.,The National Orchid Conservation Center |
Salazar G.A.,National Autonomous University of Mexico |
And 7 more authors.
Molecular Phylogenetics and Evolution | Year: 2011
A molecular analysis was performed on 56 taxa in the orchid genus Cypripedium using nrDNA ITS and five chloroplast regions (trnH-psbA, atpI-atpH, trnS-trnfM, trnL-F spacer, and the trnL intron). The genus Cypripedium was confirmed as monophyletic. Our data provided strong support for monophyletic grouping of eight infrageneric sections (Subtropica, Obtusipetala, Trigonopedia, Sinopedilum, Bifolia, Flabelinervia, Arietinum, and Cypripedium) defined in earlier taxonomic treatments, and paraphyletic grouping of two sections (Irapeana and Retinervi). Within the genus Cypripedium, the first divergent lineage consisted of two Mesomaerican species, and subsequently the Cypripedium debile lineage from eastern Asia was split. Our study did not support the notion that two Asian species (Cypripedium subtropicum and Cypripedium singchii) were closely related to either Mesoamerican Cypripedium irapeanum or North American Cypripedium californicum, as indicated by previous interpretations based on morphological evidences. In addition, one pair of vicariant species, Cypripedium plectrochilum (eastern Asia) and Cypripedium arietinum (North America), unique to section Arietinum, was confirmed. Furthermore, within the monophyletic section Cypripedium two previously recognized subsections, Cypripedium and Macrantha, were shown to be paraphyletic. Our results suggested that this section split into two groups based on distribution (North America vs. Eurasia) instead of such previously used, morphological traits as flower color, and the shape of the lips (labellum) and lateral petals. © 2011 Elsevier Inc.
Huang B.,Nanchang Institute of Technology |
Luo Y.,CAS Institute of Botany |
An D.,Huanglong Administration of National Scenic Spot |
Kou Y.,Huanglong Administration of National Scenic Spot
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2011
In Huanglong valley, plant patches with various sizes were developed among streams in the travertine area. This landscape provides a good opportunity for studying the relationship between patch size and plant species numbers at small scale. To gain basic understanding of the plant diversity pattern and improve our ability to conserve the rich biodiversity in Huanglong valley, we sampled a total of 122 patches, and analyzed the patch size species relationships using multiple regression and power formulation. Our study showed that patch size correlated strongly with species richness. Specifically, large patch had more number of species comparing to small ones. Other ecological factors, i. e. the depth of soil, the moss coverage of the patch and the distance among patches, had no correlation on species richness of patches. However, the distance of the patch to the edge of forest, along with patch size, correlated significantly with orchid species numbers. The relationship between species richness and areas were consistent with the power formulation S = cA z. The Z values were different with various patch size. The medium patch size (1 -10 m 2) had the largest Z value (0.2616), followed by the smallest patch size (S < 1 m 2, Z =0. 2382), and the largest patch size had the lowest Z values (S = 10 - 100 m 2, Z = 0. 2050). These results indicated that the medium patch size had the highest increase rate on species number accumulation, whereas the largest patch size had the lowest increase rate.
Hou T.,Beijing Forestry University |
Jin H.,CAS Institute of Botany |
Liu H.,Beijing Forestry University |
An D.,Huanglong Administration of National Scenic Spot |
Luo Y.,CAS Institute of Botany
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2010
All orchids have an obligate relationship with mycorrhizal symbionts during seed germination under field conditions, and in many species, the dependency on fungi as a carbohydrate source is prolonged into adulthood. Diversity of orchid mycorrhiza is defined as the species of mycorrhizal fungi compatible with an orchid and the shape of compatibility links between orchids and fungi are referred to as webs. According to traditional records, the majority of mycobiont in terrestrial orchid mycorrhiza belonged in several certain taxonomic groups of basidiomycetes, and there were specific relationships between orchids and fungi. Subsequent studies indicate a more complex situation. The factors which influence the diversity of orchid mycorrhizal fungi is not exactly known. Trophic styles, geographical differences, environmental conditions, or life stages have been reported to play a role in the fungal diversity. Considering the huge temperate zone and alpine mountains, China has rich terrestrial orchid resources. The Huanglong Valley in Sichuan Province, at an elevation of 3100 -3569 meter and 3. 5kilometers long, is the largest travertine region in the world. Profuse terrestrial orchids from 30 species in 19 genera were found in this narrow valley. Huanglong Valley is one of the temperate terrestrial orchid distribution centers in China. These orchids grew in two different habitats. One was open shrubs with travertine stream flows; another was relative dense mixed coniferous broad-leaved forests without water flows. Cypripedium flavum, Galearis diantha, Ponerorchis chusua and Phaius delavayi were the main orchid species found in open shrub habitat with abundant individuals. Tipularia szechuanica, Platanthera minutiflora, Corallorhiza trifida and Neottia acuminata were the dominant orchid species in forest habitat, the latter two species were myco-heterotrophic, which rely on mycorrhizal fungi throughout their lifetime. From a conservation perspective, this study investigated the diversity of mycorrhizal fungi of temperat wild orchids in the Huanglong Valley, and whether the fungal diversity would vary between different growing periods of orchids, and with the species of host orchids from different habitat. Samples were taken in the different seasons over one year. The mycorrhizal fungi were isolated in tissue blocks cultivation, and identified by using micro structure examination and ITS gene sequence analysis methods. We investigated the diversity of mycorrhizal fungi with species number and Simpson's diversity index. The phylogenetic diversity of fungi isolates was also investigated. Forty-one fungi species were isolated from the samples. It was very rare for the eight orchids to share similar species during the same growing period. The molecular phylogeny indicated that the fungi mainly belonged to Helotiales and Hypocreales of Ascomycota, and Tulasnella of Basidiomycota. The Ascomycota was dominant, containing 35 species. Mycorrhizal fungi specificity at the species level was not been found except for Galearis diantha, which was associated with only Hypocrea fungi through out the whole growing season. Species number and Simpson diversity index (D) of mycorrhizal fungi from the orchids growing in a forest habitat were higher than those in a travertine habitat. The variation patterns of mycorrhizal fungi diversity from both habitats were synchronized with the season changing pattern of the Huanglong Vally. The peak of mycorrhizal fungi diversity appeared in the vegetative period, and the minimum value was in the fruiting period. Moreover, the changing pattern of the mycorrhizal fungi diversity between different growing periods was closely associated with the nutrition requirement of the orchids during different growing stages.
Huang B.,Nanchang Institute of Technology |
Kou Y.,Huanglong Administration of National Scenic Spot |
An D.,Huanglong Administration of National Scenic Spot
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2012
Phaius delavayi is a long-lived, polycarpic, pseudobulbous clonal orchid species and is endemic to China. Generally, the flower phenology, flower life span, and pollination success are important features for plant species evolution and conservation. Those features in Phaius delavayi were studied detailed in 2005-2007 in Huanglong Valley, Sichuan. The results showed that the plants have 3 or 4 leaves, and the largest leaf were 16.9-17.5 cm long, 4.8 -4.9 cm wide. The inflorescence is sparsely 1-7-flowered (with mean 3), exceeding height of leaves, 18.4-19.5 cm. Flowers widely opening, with 1.9-2.2 cm long, 1.1 cm wide labellum, and 1.0-1.2 cm long spur. Length of the leaf and floral traits were not significant different, as well as flower phenology during three years. Fruits were 20.78 mm long, 8.10 mm wide, and 00424 g weight. The inflorescence growth began in mid May and last about 50 days, continued until early July. Flowering began in mid June and last about 6-7 weeks, continued until late July/early August, with 80%-90% flowers flowered in a peak time (last about 10 days) in early July. Life span of inflorescences showed considerable variation among years, which were 23, 21, and 29 days for 2005, 2006, and 2007, respectively. The flower life span was closely correlated with pollination, that with successful pollination was 15-19 days, significantly shorter than that of flowers without pollination (17-22 days). Fruit maturity was in mid-latter September, and the leaves were yellow and withered. The results of pollinia viability and stigma receptivity experiments showed that the flowers are self-compatible, but the reproductive success is strictly dependent on visitation by pollinia vectors (Bombus hypnorum and B. lepidus), and there is no autogamy and apogamy in this speices. The stigma has receptivity at the first day of flowering, and can last about 15 days, and lost receptivity completely 20 days after flowering. The fruit set was higher 1-10 days after flowering than that 15 days after flowering. The pollinia has also viability at the first day of flowering, and can last about 15 days, lost viability completely 20 days after flowering, but there was no differences in pollinia viability during one to 15 days. The lost of stigma receptivity was sharper than that of pollinia viability. The pollinia viability and stigma receptivity can last even to the flower withered. Reproductive success showed considerable variation among years and was decline with year. The pollinia removal and nature fruit set were 18%-51% and 10%-36%, respectively, and spraying of pesticides in Huanglong Valley may play a role for the declination of pollination success.