Abstract:To explore the floristic characteristics of seed plants in Yaoshan National Nature Reserve, the flora was investigated and analyzed. The results indicated that there were 1978 species of seed plants in Yaoshan, which belong to 698 genera in 132 families. Among them there were 5 families, 8 genera, 10 species in gymnosperm; 127 families, 690 genera, 1968 species in angiosperm. At family level, the proportion of the tropic elements was slightly higher than others and reached 53.57% and the temperate ones accounted for 44.05%. While at genus level, the temperate elements (69.76%) had obvious advantages compared with tropic ones (25.76%), reflecting the transitional characteristics form tropic to temperate of this region. Twenty-eight genera were endemic to China containing 11 woody genera, such as Ginkgo, Eucommia and Cyclocarya, et al. And genus consisting of only 1 species or few species accounted for 87.25%, among which 45 were monomorphic genera, suggesting the ancientness of this flora. The flora of Yaoshan and neighboring areas (Baotianman Mountain, Jigong Mountain and Tianmu Mountain) all showed temperate characteristics, and Yaoshan has the highest proportion of temperate components. On the whole, the Yaoshan shows obvious temperate characteristics, and the origin of the flora is mainly East China, and it is infiltrated by North and Central China. To sum up, the study would provided scientific basis for the sustainable utilization of plant resources, the assessment and protection of rare and endangered plants in Yaoshan area.

Abstract:There are 20 national and 5 provincial key protected wild plants in Guangzhou. According to the population size and number and the threaten category, total 14 indigenous species are proposed to list as key protected wild plants in Guangzhou. The conservation strategies are provided based on the evaluation and analysis to their current growing status and threaten factors.

Abstract:The Salix annulifera C. Marquand & Airy Shaw was originally described based on F. K. Ward 5870, which includes two totally different taxa (S. annulifera and S. austrotibetica N. Chao). According to the Shenzhen Code, F. K. Ward 5870(K-000335077) is designated here as the lectotype of S. annulifera. The F. K. Ward 5870 (K-000335083) is excluded from S. annulifera, and recognized as S. austrotibetica. Furthermore, the descriptions of S. annulifera is revised.

Abstract:Boesenbergia quangngaiensis N.S. Ly, a newly recorded species of Zingiberaceae from China was discovered and reported here. It can be distinguished from the other species of Boesenbergia by the greenish and abaxially glaucous leaves, the terminal inflorescence, the flowers alternately 2-ranked and facing one way, the broadly obovate labellum, centrally with deep red band at the base, apical purple-red patch in the middle. Chinese descriptions, colour plates of the newly recorded species and a key to the species of Boesenbergia in China were provided in this paper.

Abstract:Tainia acuminata Averyanov is reported from China for the first time. Description and color photos are provided. This species is similar to T. cordifolia Hook. f., but differs in its narrowly lanceolate sepals and petals; broadly lanceolate, acuminate lip entire, irregularly crisped-undulate along margins, disk with 3 insignificant low keels.

Abstract:In order to understand the systematical significance of Geodorum recurvum in Orchidaceae, the development of both embryo sac and embryo were observed by using paraffin section method. The results showed that ovule primordium of G. recurvum developed slowly before blooming, and then developed quickly into “tree-like two-branch branching structure” after pollination, archesportial cells differentiated at the top of branches, and the embryo sac began to develop. The development of embryo sac belonged to polygonum type, ovule had two layers of integument cell. Archesportial cell developed into embryo sac mother cell by expansion and enlongation. The embryo sac mother cell formed linear tetrad by meiosis, and one functional megaspore at micropylar. Functional megaspore divided into 8-nucleu embryo sac by three times division successively. The developement of embryo had chenopodium type and asterad type. After double fertilization, the zygote divided into a basal cell and an apical cell by a transverse division. The basal cell formed cell group by division many times, and the cells formed suspensor cells situated through expansion and enlongation along different directions. The apical cell had two division type, one formed quinoa type embryo by transverse division, another did asters type embryo by longitudinal division. Therefore, it was suggested that the evolution of G. recurvum belonged to primitive in Orchidaceae.

Abstract:In order to understand the expression patterns in different tissues and under abiotic stress of ascorbate peroxidase (APX) gene family in Phyllostachys edulis, seven PeAPXs were obtained from the genomic database of P. edulis. PeAPXs could be divided into three subfamilies, including cytoplasmic, peroxisome and chloroplast/mitochondrion types based on the predictions of subcellular localizations. There were drought, cold, and light responses elements in promoter sequences of each gene, such as Box-4 and G-Box. The expression of PeAPXs were different among seven tissues, showing tissue specificity. qRT-PCR revealed that there were great differences in the expression pattern of each gene under drought, salt and low temperature stress. The expression of PeAPX2 was maintained at high level under three stresses. The expression of PeAPXs were induced by low temperature stress. Under drought stress, the expression of PeAPX1 was down-regulated, while the expression of PeAPX3, PeAPX6 and PeAPX7 were not detected. Under salt stress, all of PeAPXs were up-regulated except PeAPX3 and PeAPX5. Therefore, PeAPXs may be involved in different abiotic stress processes and play an important role in the growth and development stage of P. edulis.

Abstract:In order to explore nectar variation and its effect on pollinators of Goodyera foliosa, a nectar rewarding orchid, the nectar volume, total sugar concentration and the composition and content of soluble sugar in single flower in different time within a day were detected by using capillary method, refractometer and high performance liquid-evaporation method. The foraging behavior of pollinators was observed by video camera. The results showed that the volume of single flower nectar reached up to maximum [(7.19±2.29) μL, n=10] at 10:00, and the sugar concentration to maximum [(25.85±1.83)%; n=10] at 16:00. The main soluble sugar in nectar was fructose and sucrose, and the highest content of fructose was 78.310 mg/g at 10:00 am and that of sucrose was 247.600 mg/g at 16:00 pm. The visiting time of Apis cerana was from 9:00 to 15:00 every day, and the peak period was between 10:00 am and 14:00 pm. And the visiting time of Bombus friseanus was from 8:00 to 16:00 every day, and the peak period was from 10:00 to 12:00 and from 16:00 to 18:00. The visiting frequency of the two pollinators was correlated with the changes in nectar volume and sugar concentration of single flower of G. foliosa. They tended to visit flowers with high nectar volume and sugar concentration. Sucrose was the predominant component of nectar in G. foliosa, which can effectively attract all kinds of bees, butterflies and ants to visit flowers with high enthusiasm and access frequency. However, the Apis cerana and Bombus friseanus which could carry the pollen of orchid were major effective pollinators. Therefore, the matching of flower shape and size of visiting insects determined whether they were effective pollinators.

Abstract:In order to study the genetic diversity of Horsfieldia pandurifolia from Xishuangbanna and Lincang of Yunnan province, genetic diversities of 56 samples from 8 populations were tested by AFLP markers. The results showed that a high genetic diversity existed in H. pandurifolia, with the percentage of polymorphic sites were 75.16% at species level, and 36.20% at population level. Moreover, a high level genetic variation (75.45%) within the population was detected through AMOVA analysis, but only existed 24.55% between populations. Analysis of correlation between geographical distance and genetic distance showed that there was positive correlation (r=0.1197，p=0.3210) among the populations，but it was not significant. Based on the UPGMA clustering analysis of the coefficient of genetic similarity, the 8 populations were divided into 3 groups at a similarity coefficient threshold of 0.951. On the basis of these results, the strategy was proposed for the conservation germplasm and laid a foundation for the development and sustainable development of H. pandurifolia.

Abstract:Yunnan province is the refuge and birthplace of magnolias, the primitive and evolutionary species of Magnoliaceae are distributed alternately in there. It is very important to study the phylogenetic evolution and classification of Magnoliaceae.In this study, ISSR molecular markers were used to study 48 species of Magnoliaceae wild plant resources in Yunnan province.The results showed that a total of 151 bands and 151 polymorphic bands were amplified from the 10 primers, and the percentage of polymorphic bands was 100%. The total number of observational alleles (Na), effective alleles (Ne), Nei"s genetic diversity index (H) and Shannon"s information index (I) of the 48 Magnoliaceae plants were 2.0000, 1.5645, 0.3379 and 0.5101, respectively. The total genetic diversity index (Ht) was 0.3680 and the intergeneric genetic diversity index (Dst) was 0.2519. The intergeneric genetic diversity accounted for 68.4% of the total genetic diversity index. The coefficient of gene differentiation (Gst) was 0.6840, and the gene flow (Nm) was 0.2310. 48 species of Magnoliaceae plants were divided into 7 groups by the UPGMA clustering, and the clustering results were not consistent with the classification of genera, but distributed in different genera.and Magnolia rostrata, Michelia flaviflora and Michelia sphaerantha may be the ancestors of Magnoliaceae in Yunnan province.The 48 species of Magnoliaceae wild plants in Yunnan province have high genetic diversity in general, but they have high inter-genus genetic variation and small gene flow, which may lead to the risk of genetic drift. Moreover, the clustering results are different from the classification system of Liu Yuhu.The results provide an important basis for the origin, evolution and classification of Magnoliaceae at the molecular level.

Abstract:In order to understand the thermo-sensitivity of heat sensitive mutants of Arabidopsis thaliana, the thermo-sensitivities were compared among six mutants, including hsp70-15, apx2, hop1-2-3, hsfa7a, fes1a and hot1. The results showed that the thermo-sensitivities of six mutants were higher than that of WT, but there were significant difference among them. The 8-day-old seedlings were adapted at 38℃ for 2 h at first, then they were under heat stress at 45℃. Seedlings of mutant hot1 showed albinism with high mortality under 45℃ for 90 min. Seedlings of mutant fes1a also suffered high death rate under 45℃ for 105 min. Further, seedlings of mutants apx2, hsfa7a and hop1-2-3 showed almost identical injury phenomenon under 45℃ for 135 min, their heat injury were more severe than that of mutant hsp70-15. Therefore, the thermo-sensitivities of six mutants were in the order of hot1>fes1a>apx2, hsfa7a and hop1-2-3>hsp70-15.

Abstract:In order to reveal the invasion mechanism of Mikania micrantha affecting soil nutrient circulation through allelopathy, the effects of two allelopathic substances from M. micrantha (i.e. chlorogenic acid and β-caryophyllene) on soil nitrogen and related functional bacteria of nitrogen cycle were studied using exogenous addition culture experiments. The results showed that both chlorogenic acid and β-caryophyllene significantly reduced the content of soil ammonium nitrogen, and chlorogenic acid increased significantly the content of soil nitrate nitrogen, while β-caryophyllene had no significant effect. The main reason was that both chlorogenic acid and β-caryophyllene significantly inhibited the reproduction of azotobacter and ammonifying bacteria, and chlorogenic acid significantly promoted the growth of ammonia-oxidizing bacteria and nitrifying bacteria, while β-caryophyllene only promoted the reproduction of ammonia-oxidizing bacteria, and had no effect on nitrifying bacteria. So, it was concluded that M. micrantha invasion could affect the growth of functional bacteria associated with nitrogen cycle through the allelochemicals, thus altered the soil nitrogen cycle.

Abstract:In order to protect Ormosia boluoensis resources, the community characteristics, including species composition, population structure, spatial pattern, intraspecific association and interspecific relation with dominant species were studied based on 0.6 hm2 fixed plot in Xiangtoushan National Nature Reserve in Guangdong Province, which is the concentrated distribution area of O. boluoensis. The results showed that there were 4 503 individuals with DBH (diameter at breast height)≥1, belonging to 84 species, 57 genera and 38 families. The dominant species of the community were Castanopsis eyrei, Rapanea neriifolia, Symplocos congesta, Michelia maudiae and Syzygium buxifolium. The importance value of O. boluoensis was only 1.84, and its diameter class structure showed an inverse ‘J’ type. For spatial pattern, Ormosia boluoensis showed an aggregated distribution at scale of 0-22.1 m and a random distribution at scale of 22.2-30.0 m. As for interspecies relationship, there was no obvious association between O. boluoensis and Castanopsis eyrei and only a weak negative correlation with Syzygium buxifolium on some scales. There was a negative correlation with Symplocos congesta, while a positive association with Rapanea neriifolia and Michelia maudiae. There was positively strong associated between seedlings and adult trees of O. boluoensis at scale of 0-3.7 m, and positively associated between young trees and seedlings at scale of 0-5.9 m, but the association between adult and young trees trees was weak. Therefore, the spatial distribution pattern of O. boluoensis was affected by negative density restriction, seed diffusion limitation and habitat heterogeneity. So, proper seedlings transplantation and thinning in the community could be implemented in the later management.

Abstract:In order to select garden species with strong drought tolerance, six common garden species, such as Lonicera maackii, Cercis chinensis, Lagerstroemia indica, Vitex negundo var. heterophylla, Lespedeza bicolor, and Broussonetia papyrifera were used by water control test in pots, and the morphology, soil water content, contents ofchlorophyll and propylene dialdehyde (MDA), superoxide dismutase (SOD) activity in leaves were studied. The results showed that soil water content decreased with the extension of drought stress time. The growth of Lonicera maackii, Lespedeza bicolor and Vitex negundo var. heterophylla look like better, while that of Lagerstroemia indica, Cercis chinensis and Broussonetia papyrifera showed wilting and falling. Photosynthesis pigment contents of six species first rose then fall, the activity of SOD showed general upward trend except for Lagerstroemia indica, and the content of MDA rose continuously under drought stress. Therefore, the drought resistance of Lonicera maackii, Lespedeza bicolor and Vitex negundo var. heterophylla is strong, and that of Lagerstroemia indica, Cercis chinensis and Broussonetia papyrifera is weak.