The floristic characteristic, position in Chinese floristic division, and the origin and development of the flora of the Cangshan Mountain Range (the Dali Range) were discussed from different aspects, based on the local seed plants of 2503 species, 45 subspecies, 194 varieties, belong to 852 genera in 164 families. Preliminary conclusions are as follows: The Cangshan Mountain Range belongs to three rivergorges subregion, Hengduan mountain region, SinoHimalayan forest subkingdom, East Asiatic Kingdom, in Chinese floristic division. The floristic characteristic of seed plants of the Cangshan Mountain Range is temperate. Because of the geological events of the collision between Eurasian Plate and Indic Plate, the Tethys fading away, and the uplift of Himalayas, the elements from Gondwana land, Mediterranean and ArcticTertiary gradually developed into its modern flora. The endemism within the flora is rich, with the neoendemic elements dominant. It shows that the Cangshan Mountain Range is not only a refuge for some ancient floristic elements but also a differentiation center for young floristic elements. It is an important floristic spot connecting floristic elements from different directions. And the distribution limits of a great deal of elements also are here.
Two genera and five species of Orchidaceae: Plocoglottis, Drymoda, Plocoglottis bokorensis, Drymoda siamensis, Ceratostylis siamensis, Pecteilis hawkesiana, Coelogyne trinervis, Eria spirodela, are described as new records of flora to China. Every genus and species gives the character described and compare with similar species.
Originally Tangut refers to a branch of the Qiang tribe in western China during the Sui and Tang Dynasties, ie. Dangxiang Qiang. Dangxiang Qiang gradually grew stronger in the Northern Song Dynasty, and established the Western Xia regime. They called themselves Daxia. We collected more than 40 botanical names that had the stem “Tangut” in the specific epithets. We analyzed their protologues, determined the collecting localities of their holotypes, lectotypes or syntypes in order to delimitate the geographical range of the Tangut region in floristics. Previous research results on the Tangut region were also considered. We suggested that the north boundary of Tangut region lied at the south slope of the Qilian Mountains (northernmost point at Jingtie Mountain), and then extended southwards through the Tao river reaches, ended at Burgan Buda Mountains and Amen Mountains, the west boundary started from the eastern margin of the Qaida Basin (Qaida Basin not included) and the east boundary extended from the Tao River reaches to northeastern Sichuan, roughly lied at the north of Song pan and Li Xian. We know that much more facts should be considered to deliminate the range of a flora region and it’s not enough to consider only the type localities of some taxa. However, considering the scope of this flora region is not large and we have analyzed more than 40 taxa, our analysis could be regarded as an exploratory attempt to delimitate the boundaries of a flora region from a historical viewpoint.
Bruguiera cylindrica was first reported from Haikou in China by Merrill in 1927. The specimen cited by Merrill was researched carefully and the result reveals that the so called Bruguiera cylindrica is only a mistaken identification by Merrill. This specimen is Bruguiera sexangula. So Bruguiera cylindrica is not distributed to China and the foregone research results of this species should be revised.
Pedicel is a stalk connecting sporangia with frond in ferns, and its structure and function are not clear. In this paper, we studied the pedicels of Dryopteris zhuweimingii and Pentarhizidium orientale. We found that the pedicels consist of three lines of cells, and the cell wall can be separated into two layers. The inner layer is secondary cell wall (S1) that spiral and cling to the outer layer. The outer layer is primary cell wall. And when we broke the pedicel into two sections, the inner layer of the cell wall could be pulled out like a spiral belt. This structure may be important to support and protect the sporangia.
A species of the genus Dichocarpum (Ranunculaceae), Dlobatipetalum, is described as new from southeastern Yunnan Province, China. The morphological differences between it and its ally, Dmalipoense, are given.
Paraisometrum mileense is endemic to China and was considered to be extinc, after its rediscovery it received much attention from the botanists as well as the public. Preserving its seeds in a seed bank gives a reliable way for long term conservation; however its seed dormancy status and germination requirements are scarcely studied. In this study we checked its embryo size by Xray imaging, the presence of fully developed embryo ruled out the possibility of morphological dormancy. Freshly matured seeds germinated readily at relatively high temperatures (over 20℃) and gibberellic acid as well as moist chilling promoted germination at lower temperatures (below 20℃) significantly, this indicates the seeds are nondeep physiologically dormant. Seeds germinated better at constant temperatures, this is probably an adaption to shaded environment. The germination also responded significantly to KNO3, and KON3 is considered to be an indication of gap and less competition in the field.
Cyclic electron flow (CEF) around photosystem I (PSI) is an important mechanism for photoprotection in higher plants under environmental stresses. However, the response of CEF activity to growth temperature has not been clarified. We here monitored gas exchange, chlorophyll fluorescence, and the P700 redox state over a range of light intensities in leaves of tobacco cultivar ‘k326’ grown at 24/18℃ and 32/26℃ (day/night). No significant difference was found in the capacity of photosynthetic CO2 assimilation between the plants grown at 24℃ and 32℃. In addition, the light response changes in the photochemical quenching of photosystem II (Y(II)) and nonphotochemical quenching (NPQ) did not differ significantly between those plants. Light response curves indicated that the plants grown at 24℃ and 32℃ displayed the same level of electron flow through PSII (ETR II) irrespective of light intensity. However, under intense light, plants grown at 24℃ showed significantly higher electron flow through PSI (ETR I). The ETR I/ETR II ratio was significantly higher in plants grown at 24℃ when exposed to intense light. Furthermore, after shortterm treatment with strong light at 24℃, the maximum quantum yield of photosystem II (Fv/Fm) was significantly higher in plants grown at 24℃ than that grown at 32℃. Taken together, our results suggest that enhancement of CEF activity in plants grown at 24℃ alleviates PSII photoinhibition, which is an important strategy in tobacco for acclimating to a relatively low growth temperature.
The effects of drying rates on the desiccation tolerance of Citrus maxima ‘Feizhouyou’ seeds at different developmental stages were studied in this paper. For seeds harvested at 130 days after anthesis (DAA), 190 DAA, 245 DAA and 275 DAA, slowdried seeds had higher desiccation tolerance than those rapiddried, with difference at significant level (P < 005). However, such improvement was little for seeds harvested at 155 DAA and 220 DAA, indicating that effect of drying rate on desiccation tolerance depends on seed developmental stages. These results accorded with previous reports on orthodox soybean seeds and maize embrys. It was suggested that the effects of drying rate on desiccation tolerance of intermediate Citrus maxima ‘Feizhouyou’ seeds mainly resulted from expression and accumulation of some desiccationrelated proteins induced by slow drying. On the required genetic basis, desiccation tolerance in seeds can be induced only at suitable seed developmental stages.
Total DNA from 27 species including Aleuritopteris humatifolia and Achrysophylla and related taxa was extracted in this research, and the rbcL, trnLF and matK sequences were amplified and sequenced. The sequences were aligned by ClustalX. The phylogenetic trees were constructed by Maximum parsimony methods and the intraspecific and interspecific genetic distance were computed in MEGA 60. The results showed as follows: no significant difference among rbcL, trnLF and matK sequences of one sample of Ahumatifolia and two samples of Achrysophy
lla, and the maximum genetic distance between Ahumatifolia and Achrysophylla were less than the minimum genetic distance between Ahumatifolia and other closely related species. Therefore, our study support the taxonomic treatment of reducing Ahumatifolia to synonym of Achrysophylla based on our phylogenetic analysis combining the evidences from their morphological characters of blades, spores, indusia, and rhizome scales.
We quantied intraspecic variation and covariation of leaf mass per area (LMA), leaf dry matter concentration (LD), leaf frost sensitivity (LFS) and Fv/Fm of leaves of 8 Lithocarpus dealbatus populations across the geographical distribution from north to south to determine the magnitude and whether it is related to environmental conditions, latitude and mean annual temperature. The results showed that the total variation (coefcient of variation) of LMA, LD, LFS and Fv/Fm were 160%, 177%, 211% and 401% respectively. The total intraspecic variation was contributed by the difference among populations, individuals and leaves. The difference among populations accounted for the largest total variation in LMA, LD and Fv/Fm, whereas the difference among leaves accounted for the largest total variation in LFS. On population level, LMA was significantly positive related to the latitude and Fv/Fm was significantly negative, but LD and LFS were not related to the latitude. LMA decreased while Fv/Fm increased significantly with the increase of mean annual temperature. LD was a downward quadratic variation, and LFS was upward with the increase of mean annual temperature. The principal component analysis of four functional traits showed that no population was located nearer to the origin of the first and second principal component, and populations at the edge of distribution area located at both sides of the first principal component axis. The results suggested that the environmental variation in the distribution could cause intraspecic variation of functional traits. There is no population could represent a species in functional traits. When an average trait value for species is considered and trait comparisons are done among species, intraspecific variation of traits could not be ignored.
Yulong Snow Mountain (Jade Dragon Snow Mountain), located in northwestern Yunnan, is belonging to one of three biodiversity centers of China. In this paper, we analyzed the composition of seed plant resource species in Yulong Snow Mountain based on databases and checklists of seed plants, and specimens collected recently in this area. More than 2815 seed plant species in Yulong Snow Mountain region were recorded, among which 96 species are endangered. Furthermore, we classified and evaluated these plant resources based on their use and biological characteristics. In addition, we propose a systematic and sustainable approach to solve the conflicts between the conservation and the economical development. This study updated the checklist of seed plants of Lijiang Alpine Botanical Garden, while also documented the basic information of plant resources in Yulong Snow Mountain. These findings provided scientific basis for future research and conservation.
The first survey of vascular epiphytes was conducted using ground based inventory assisted by single rope technique in the recentlyestablished Bulong Nature Reserve, Xishuangbanna, China. Results indicated that vascular epiphytes were abundant and diverse there. On a total of 77 phorophytes in six plots (96 trees were examined in total, covered ca. 02ha area), 1756 individuals were recorded and were identified to 103 species (47 genera, 14 families). Compared with other regions, the epiphytes were as diverse as Paleotropics, and more diverse than temperate zone, but significantly less than the Neotropics. Orchids and ferns comprised 60%, 24% of the total flora, respectively, while others only took up 16%. The highest species richness and richest lifeform diversity was found in the middle canopy zone from 10 to 15m (51% of total species), where also supported high individual abundance (19% of total individuals). Besides the middle canopy, the most abundant zone of epiphyte individuals was detected at the base of the trunk (zone 0-5m, 24% of total individuals and 37% of total species), indicating another important niche for epiphytes in this forest environment. Primary hemiepiphytic figs were rare in the area and were not found on the surveyed host trees, while hemiepiphytic Araliaceae species (Schefflera elliptica and Tupidanthus calyptratus) were popular.
Based on the investigation of 1ha plot, the primitive monsoon forest on the valley of lower Luzhi River in Yunnan was studied. The height of the community is 15-20m, and tree layers are divided into 2 layers, which is dominated by deciduous tree species Lannea coromandelica and evergreen tree species Cipadessa cinerascens. One hundred and sixteen vascular plant species were recorded from the plot, including 36 tree species, 14 shrub species, 43 herbaceous species, 43 liana species and 2 epiphyte species. ShannonWienner index is 22824 and Simpson index is 08321 from the 1ha plot. Total 1764 trees individuals with DBH ≥1cm were recorded in the plot. This community is dominated by phanerophytes. The forest is dominated by the microphyllous species which makes up 3932% of the total. The forest is also dominated by the species with simple leaves (make up 7350%), papery leaves (make up 6923%), none caudate leaves (make up 8120%) and entire leaves (make up 6752%). The species/area curve shows that it is flatten at 2000m2, which is suggested to be the minimum sampling area for the forest. This community could be recognized as Lannea coromandelicaCipadessa cinerascens formation.
Genus Asarum contains several plant species that are mostly used as precious drug resources. In this study, 126 distribution records of 3 Asarum species and relevant 28 environmental factors data were collected, then a geographical distribution model of the genus medicinal plants in China was made by Maxent and the ArcGIS spatial analysis technique. The results showed that the 3 Asarum species have a wide potential distribution region. High suitable region and suitable region were 3125km2 and 276042km2 respectively. Among the environmental factors, 3 precipitation factors (annual precipitation, precipitations in the most dry season and the most warm season) are the main ones that can affect the distribution of the 3 Asarum medicinal plants. This study can provide a useful reference for the collection and cultivation of Asarum medicinal plants.
In this study, we investigated Rhododendrons in Baili Rhododendron nature reserve and recorded species and detailed information of their distributions. A total of 33 species belonging to 6 subgenus, 4 sections and 11 subsecions were observed and the altitudes were ranging from 1300m to 1800m. In general, most Rhododendron species grew together in their typical habitats whereas a few species occurred fragmentally. In addition, we evaluated the conservation status of these 33 Rhododendron species. On the basis of available information, we addressed some problems taking into account the population structure and development of tourism, and suggestions regarding conservation and utilization of Rhododendrons were finally proposed.
