Abstract:In order to understand the effects of phylogenetic diversity and phylogenetic structure on decisionmaking of island plant diversity conservation, the relationship among species richness, phylogenetic diversity and phylogenetic structure in angiosperm communities in Wuzhizhou Island, Hainan, China were studied. The results showed that there were 10 formations of vegetation in Wuzhizhou Island. Species richness was positively correlated with phylogenetic diversity in 22 plots, but the order of conservation priority indicated by phylogenetic diversity and species richness were not completely consistent. Species richness and phylogenetic diversity of forest communities were greater than those of shrub and herb communities. Four plots are phylogenetically overdispersed and three are phylogenetically clustered in forest communities. Pandanus tectorius bushland showed the highest phylogenetic diversity in shrub communities, while did Scaevola sericea bushland in herb communities. Shrub and herb communities were mostly phylogenetically clustered. Communities near to the sea or to the anthropic zones were likely to be structured by habitat filtering, which far from the sea and the anthropic zones were likely to be structured by competitive exclusion. Therefore, species and phylogenetic demensionality, together with environmental factors, succession stages and island exploitation modes, should be considered in conservation of island plant diversity.

Abstract:The aim was to discuss the evolvement mechanism of plant functional traits in island, the functional traits of wild plants in Pingtan Island and Fuzhou National Forest Park were compared. The result showed that common families of wild plants in Island and continent accounted for 63% of total families, and common species accounted for 19% of total species. Herbaceous plants in island accounted for 65.75% of total plants for adapting to strong wind, drought and barren environment. The leaf-size class of island plants was smaller than that of continental plants. The plants with hairy leaves accounted for 62.39% of total plants in island, and tended to be lignified and succulent. Island plants mainly adapt r-reproductive strategy with high reproductive ability. The florescence of island plants was longer than that of continental plants. The spreading ability of island plants improved with high caryopsis and achene proportion, while drupe and berry proportion was low. The mini fruits accounted for 79.20% of total plants in island. The main dispersal mode of island plants tended to be wind force and heterogyna. In general, the wild plants in island and continental had the same origin; however, to adapt to fragile island eco-environment, the functional traits of island plants related with adaption-reproduction-dispersal ability had been evolved, showing strong adaptability to radiation, improved reproductive ability and spreading ability.

Abstract:Based on the biodiversity investigation of 121 offshore islands of Hong Kong, the fruit types and seed dispersal patterns of 1035 species were analyzed. The results showed that fruit types could be divided into 14 types, among which the top 4 types were capsule, drupe, berry and achene, accounting for 22.57%, 13.29%, 11.7% and 11.07% of the total, respectively. There were 4 main dispersal patterns of seeds, such as animal dispersal (779 species, including 722 species by birds), wind dispersal (399 species), human dispersal (29 naturalized species) and flow dispersal (60 species). Meanwhile, there were 188 species with more than 2 natural dispersal patterns (excluding human dispersal). In addition, the dispersal by birds and other animals plays an important role on the secondary vegetation formation of these offshore islands.

Abstract:In order to understand the mechanism of phenotypic variation in Panax notoginseng, the relation between phenotypic variation and climatic factors of 3-year-old P. notoginseng was studied cultivated in Yunnan and Guangxi by using multivariate statistical analysis combined with GIS technology. The results showed that the variation coefficient (CV) of plant stem mass, underground part mass and total mass were high, while that of aerial part ratio and underground part ratio were low. Correlation analysis showed that phenotypic variation was influenced by various climatic factors. The effect of precipitation on phenotypic variation of P. notoginseng was stronger than that of temperature. The range of precipitation seasonality was a key climatic factor for phenotypic variation of stem diameter and leaf area. Underground part mass and total mass of P. notoginseng decreased with increment of mean annual temperature, annual precipitation and precipitation of the driest month, and which increased with increasing of mean monthly temperature range and isothermality. The increment of sunshine duration would decrease of aerial mass ratio of P. notoginseng, and accelerate the accumulation of underground part mass and total mass. Therefore, it was suggested that the variation in morphological traits of P. notoginseng was strong with the changes in climate condition of producing area, which would be adapted to heterogeneous environments.

Abstract:To evaluate the absorption and purgation capacity of 52 landscape trees to atmospheric sulfur (S) and fluorine (F) pollution in Northern Zhejiang, the leaf S and F contents of trees grown in chemical industry zone (pollution area) and Central Park (clean area) were determined, and their phytoremediation capabilities to pollution environment were evaluated. The results showed that there were significant differences in leaf S and F contents among 52 species, and variations between different sampling points and different life forms were also significant. The absorption efficiencies of shrub on S and F were both slightly lower than that of arbor, but higher than small arbor, meanwhile, the leaf S and F contents of deciduous species were higher than that of evergreen species. According to the leaf bioconcentration factors (BCF) and contents of S and F in species, these 52 landscape trees could be divided into five clusters, and several species with higher comprehensive absorption ability on S and F pollutions were screened out, such as Pterocarya stenoptera, Salix babylonica, Pyracantha fortuneana, Magnolia grandiflora, Loropetalum chinense, Zelkova serrata, Osmanthus fragrans and Acer palmatum ‘Atropurpureum’, et al. These would provide references for the pollution control of S and F as well as phytoremediation in northern Zhejiang.

Abstract:In order to rational utilization the germplasm resources, the genetic variation of leaf and growth traits in nine excellent clones, including F1, SR3, SR9, SR14, SR17, SR18, SR25, SR38, SR41, in 5-year-old Acacia melanoxylon forest were studied. The results showed that the leaf morphology, structure and chemical traits exhibited significant differences among the clones, in which the variation coefficient of leaf morphological traits was the highest, and the leaf width (LW) and leaf area (LA) could be used as reliable indexes to intuitively distinguish clones of A. melanoxylon. The height (H) and diameter at breast height (DBH) in clones of SR18, SR17 and SR14 had significant advantage. The correlation analysis showed that LW had significant linear relationship with H and DBH, and did also between LA, specific leaf area (SLA) with DBH. However, the other traits, leaf length (LL), leaf dry matter content (LDMC), contents of carbon (C), nitrogen (N), phosphorus (P) in leaf, C/N and N/P, had weak correlation with H and DBH. The top four clones (SR17, SR18, SR41, SR14) were selected by comprehensive evaluation of membership function, which could be directly used for production and breeding as excellent germplasms in future.

Abstract:The aim was to elucidate fine root biomass distribution differences of moso bamboo (Phyllostachys edulis) at different ages. The fine root biomass (W_FRB), specific root length (L_SRL), root tissue density (D_RTD), and root length density (D_RLD) were analyzed in the horizontal and vertical direction of different age moso bamboo. The results showed that along the age of moso bamboo, the W_FRB and D_RLD increased at first and then decreased, the L_SRL decreased, and the D_RTD decreased at first and then increased. The W_FRB and D_RLD were the biggest at 60 cm from main stem, the D_RTD and the L_SRL were at 20 cm and 40 cm, respectively. The differences of W_FRB, L_SRL, D_RTD and D_RLD were not significant among different horizontal distances from bamboo stem. The W_FRB was the biggest at 10-20 cm soil layer, and the D_RTD was at 20-30 cm soil layer. The differences of W_FRB, L_SRL, D_RTD and D_RLD were not significant among different soil depthes, too. The W_FRB and D_RTD of 0-1 mm fine roots were smaller than those of 1-2 mm fine roots, while the L_SRL and D_RLD were bigger. Therefore, the age of moso bamboo had significant effects on the growth of fine roots. The L_SRL and D_RTD of 1-year-old bamboo were bigger, which display greater resource utilization efficiency. The even distribution of fine roots of moso bamboo could more efficient use water and fertilizer resources in a particular area.

Abstract:In order to understand the effects of space mutation on development of Dendrobium nobile, the leaf structure, photosynthetic characteristics and growth index between space mutation and wild type were compared. The results showed that there were thick leaf, dense stoma, and big stomatal apparatus in space mutation D. nobile. Diurnal variation of net photosynthetic rate (Pn) of the two kinds of D. nobile showed a similar bimodal curve. However, Pn of space mutation D. nobile was lower than that of wide type. The maximum photosynthetic rates of space mutation and wild D. nobile were 4.6 and 6.8 μmol m^-2s^-1, light compensation rates (LCP) were 18.3 and 12.6 μmol m^-2s^-1, light saturation points (LSP) were 1180 and 720 μmol m^-2s^-1, CO₂ compensation points (CCP) were 100 and 102 μmol mol^-1, CO₂ saturation points (CSP) were 2215 and 2090 μmol mol^-1, respectively. Fresh weight (FW) and dry weight (DW) per shoot of space mutation D. nobile was lower than that of wide type. However, due to the increment of tiller number, total biomass per pot in the space mutation D. nobile was more than that of the wild type. Additionally, the total alkaloid and polysaccharide contents in space mutation D. nobile was significantly higher than those of wide type. So, space mutation would provide a new way for breeding and quality improvement of D. nobile.

Abstract:In order to understand the effects of NaCl stress on the seedling growth of Salix spp., the survival rate, physiological response and anatomical structure of half-year-old Salix spp. seedlings were studied under salt stress by pot-culture method. The results showed that the growth of seedlings was well treated with 0.25% NaCl (light salt stress), while it was inhibited treated with more than 0.5% NaCl (moderate and severe salt stress). It was deduced that the salt tolerant threshold of Salix spp. was 0.5%. The relative water content, the content of Chl a, Chl a+b and Chl a/b decreased as salt stress enhanced, while the Chl b, proline and malondialdehyde (MDA) contents increased gradually. The activity of superoxide dismutase (SOD) and soluble protein content increased under light salt stress, but significantly declined under moderate and severe salt stress. The thickness, cuticle, palisade tissue of leaf and the diameter and periderm of root were the biggest treated with 0.25% NaCl, while under moderate salt stress, the cell length in palisade tissue of leaf decreased with loose arrangement and the cells in transfusion tissue of root was abnormal. Therefore, it was suggested that Salix spp. had tolerance to light salt stress, and undergrowth at moderate and severe salt stress.

Abstract:To reveal the genetic effect of parents on F₁ seeds reserve utilization of Zea mays L. var. saccharata Bailey, the heterosis and regression relation between parents and F₁ hybrid seeds from 19 inbred lines and 10 hybrid combinations were studied. The results showed that there were obvious differences in contents of starch, protein, fat, 100-seed weight, the weight of mobilized seed reserve and seed reserve utilization efficiency between inbred lines and F₁ hybrid seeds. There were significant differences in starch content, fat content and 100-seed weight between parents on F₁ seeds. The starch content and 100-seed weight of F₁ hybrid seeds were higher than those of parents, while other traits were lower. However, the 100-seed weight and seed reserve utilization efficiency in F₁ seeds from the combinations of FH14, Q26, GT22 and GT2 had strong heterosis by cluster analysis, which had significant difference in characters. Regression analysis showed that female parent had positive effects on the mobilized seed reserve and seed reserve utilization efficiency, but have negative influences on starch content and 100-seed weight of F₁ seeds, while male parent have negative effects on starch content and have positive effect on seed reserve utilization efficiency.

Abstract:In order to understand the reason to growth stagnation of Glehnia littoralis in summer, the heat tolerance of leaf metabolic system was studied in comparison with a companion species Calystegia soldanella as reference. The results showed that both of the deactivation temperature of photosynthetic system and the half lethal temperature of cell membrane in G. littoralis were 5℃ lower than those in C. soldanella. In contrast, the activity of the respiration system in both plants were still very high even when the temperatures reached 50℃ with a decline of 10% and 24%, respectively, showing that the respiration system was apparently more heat-resistant than the photosynthetic and membrane systems. The Gaussian regression showed that the ratio of photosynthesis rate to respiration rate was persistently lower in G. littoralis than that in C. soldanella. Therefore, it was suggested that the excessive consumption of the photosynthetic assimilates could be the cause of the summer growth stagnation of G. littoralis. In addition, the overall lower heat-resistance of C. soldanella could also be associated with the summer growth stagnation in G. littoralis, while C. soldanella did not show growth stagnation in summer because of high heat resistance.

Abstract:In order to understand the influence factors on germination of loquat (Eriobotrya japonica Lindl.) seeds, the seeds were sown on 1/2MS medium for 80 days, the effects of fruit maturity and storage conditions on aseptic germination of seeds were studied. The results showed that germination rate and seedling height had no significant difference for seeds collected at color turning stage or full mature stage for ‘Ruantiaobaisha’, ‘Ninghaibai’, ‘Tangkebaisha’ and ‘Dahongpao’, while germination rate of ‘Oobusa’ seeds collected at full maturity stage were high. The seed germination rate and seedling height of ‘Luoyangqing’ stored under 4℃ for 5 d or 10 d had no significant changes, however, which significantly decreased when the seeds were stored for 20 d or more. The germination rates and seedling heights also varied greatly under different storage temperatures, those of ‘Zaozhong 6’ and ‘Taipingbai’ stored under 15℃ or 4℃ were higher than those under 25℃, and the suitable storage time was no more than 15 d and 30 d, respectively. Therefore, it would maintain the germination ability of loquat seeds by harvesting fruits at color turning stage and appropriate storage.

Abstract:To understand the chemical constituents of Alpinia hainanensis ‘Shengzhen’, ten flavonoids were isolated from its stems by chromatographic techniques. On the basis of spectral data, they were identified as (-)-pinocembrin (1), (±)-alpinetin (2), (±)-7,4'-dihydroxy-5-methoxy-dihydroflavonol (3), uvangoletin (4), cardamonin (5), helichrysetin (6), (+)-catechin (7), (-)-epicatechin (8), proanthocyanidin A1 (9), and proanthocyanidin A6 (10). The compounds 1, 3, 5, 7-10 exhibited remarkable ABTS radical scavenging activities and compounds 7-10 displayed significant DPPH radical scavenging activities.