Abstract:To evaluate the changes in biodiversity and soil properties during vegetation restoration, the plant diversity and soil characters among five habitats, such as flood land, gravel land, reed land, Saccharum arundinaceum land and sand land, in riparion zone of Wenjiang section of Jinma River were comparative analyzed in 2015 and 2018. The results showed that there were 113 species of herbs in Wenjiang riparion zone, belonging to 80 genera and 32 families in 2015, and 161 species of herbs and shrubs, belonging to 118 genera and 57 families in 2018. With shrub layer added in 2018, the changes in community structure of flood land and S. arundinaceum land were the most significant, and that in gravel land was the smallest. In 2018, except for the flood land and S. arundinaceum land, the biodiversity indexes had little change. The richness index (D), Shannon-Wiener diversity index (H), Simpson dominance index (H') and Pielou evenness index (J_sw) showed the same variation trend among habitats, with the biggest in gravel land and the smallest in reed land. In 2018, the soil water contents (SWC) of flood land and S. arundinaceum land were significantly lower than that of other habitats, the soil bulk density (BD) of S. arundinaceum land was the lowest, but the contents of TN and OM were the biggest. Combining species matrix and environment matrix, redundance analysis (RDA) showed that BD, SWC, OM had the most significant correlation with species diversity. SWC and soil pH were the main effect factors in the gravel land and sand land, while OM in the flood land and S. arundinaceum land. On the whole, after forbidding sand mining, each habitat showed different degrees of restoration, and the restoration effect of S. arundinaceum land was the most significant. These would be conductive to providing theoretical basis for continuously improving the current situation of soil quality and promoting the restoration of riparian ecosystem in the Wenjiang section of Jinma River.

Abstract:To explore the succession rule of karst secondary forest in central Guizhou, based on the fixed-point monitoring data in 2013-2019, the dynamic changes of niche and interspecific association of karst secondary forest in central Guizhou were studied, including community species composition, niche width, niche overlap and interspecific association. The results showed that the proportion of important value of constructive species decreased in 7 years, and the dominance of species, such as Serissa japonica and Viburnum foetidum, increased significantly. Zanthoxylum armatum and Rosa cymosa occupied a wide niche, while the niche width of Stachyurus yunnanensis and Serissa japonica and other species have increased resource availability, which narrowed their niche width. The proportion of species pairs with niche overlap less than 0.2 decreased, and the relationship of interspecific competition was more complex. The overall connectivity among main species changed from non-significant positive association to significant positive association, and the proportion of positive and negative association between most species increased. In the karst secondary forest community of central Guizhou, the competition among species was intense and gradually stable, and the connection between species was strengthened. In the process of positive succession, the dominance and competitiveness of shade tolerant and mesophily species, such as Serissa japonica and Viburnum foetidum increased, but some pioneer species, such as Rhamnus heterophylla and Campylotropis macrocarpa, declined due to insufficient competition. Therefore, these would provide a reference for vegetation restoration and rocky desertification control in karst areas.

Abstract:In order to understand the response of phytoplankton community in P-restricted water from Liuxihe Reservoir in Guangdong Province to different N/P ratios, the structure of phytoplankton community was studied by adding N and P to create a gradient of N/P. The results showed that the growth of phytoplankton had been promoted significantly with the addition of N and P, and the effects of P was greater than that of N. The species specificity of phytoplankton led to the inconsistent response of phytoplankton community to nitrogen and phosphorus nutrients, phytoplankton abundance was not correlated with N/P ratio. Cyanobacteria, such as Aphanocapsa sp., Cylindrospermopsis raciborskii and Pseudanabaena sp., was more favored in conditions with high level of N and P. Dominant species of green algae, Scenedesmus bijuga preferred medium N and high P. Bacillariophyceae, such as Achnanthes sp. and Cyclotella sp. had advantages in environment with low N and low P. The threshold of P concentration for alkaline phosphatase activity (APA) ranged from 0.8 to 2.0 μmol/L. When P concentration was above 2.0 μmol/L, APA was inhibited, and the optimal P concentration for phytoplankton to maintain growth may be around 2.0 μmol/L, and the ratio of cellular N/P reached equilibrium. The cellular N/P and C/P were significantly positively correlated with supplied P concentration and supplied N/P ratio, while cellular C/N was more correlated with supplied N (P<0.05). So, these would provide a theoretical reference for water quality management in tropical and subtropical reservoirs.

Abstract:In order to explore the effects of heavy metal pollution on physiological characters of forage under different planting patterns, three forages, such as Pennisetum sinese, Lolium perenne and Juncus effusus, were single cropping and intercropping, the effects of heavy metal pollution on photosynthetic parameters, photo-synthetic pigments and heavy metal contents in leaves under different planting patterns were studied. The results showed that compared with monoculture, the contents of chlorophyll (Chl) a, Chl a+b and carotenoid (Car) of P. sinese leaves under intercropping increased significantly, while P_n, G_s, C_i and Chl b content decreased signi-ficantly, but there was no significant difference in transpiration rate (T_r). The C_i and Car content in L. perenne and J. effusus increased significantly, while P_n, T_r, G_s, contents of Chl a, Chl b, and Chl a+b decreased significantly except of Chl a content in J. effusus. The leaf and total biomass, heavy metal contents in three forage leaves increased significantly under intercropping, except that copper content of J. effusus decreased significantly. Compared with control, the photosynthetic parameters, photosynthetic pigment content in leaves, leaf and total biomass of P. sinese were significantly improved treated with low concentration heavy metal pollution, while the P_n, T_r, G_s, C_iin leaves, leaf and total biomass of L. perenne and J. effusus decreased significantly, and photo-synthetic pigment contents increased significantly, but there was no significant difference in T_r, C_i, leaf biomass of L. perenne and Chl b content in L. perenne and J. effusus. The contents of heavy metals in three forage leaves increased significantly under heavy metal pollution. The interaction of planting pattern×heavy metal pollution on photosynthetic parameters, photosynthetic pigment content, leaf and total biomass, and heavy metal content of forage leaves were significant. Therefore, on the heavy metal combined pollution soil, it was beneficial for accumulation of dry matter and absorption of heavy metals of three forages under intercropping, while under monoculture, it was more beneficial to improve their photosynthetic capacity. Under different planting patterns, the adaptability of P. sinese to heavy metal pollution was stronger than that of L. perenne and J. effusus.

Abstract:In order to understand the effects of Cinnamomum camphora litter leaves on the growth of crops and soil microbial biomass C and N, the morphological and physiological characteristics of three crops, such as lettuce (Lactuca sativa), eggplant (Solanum melongena) and cabbage (Brassica chinensis), and soil microbial biomass C and N were studied by supplied litter leaves of C. camphora with different dosage in pots. The results showed that the decomposition of C. camphora litter leaves inhibited the growth (leaf area, leaf number) and biomass accumulation of three crops. The inhibition effects were stronger with increment of litter dosage, but those were stronger at first and then weaker along the time. The contents of malondialdehyde (MDA) and soluble sugar (SS) in leaves of three crops treated with litter leaves increased significantly at early stage (20-40 days after sowing), but the soluble protein (SP) content decreased significantly. At the later stage (80 days after sowing), the difference of MDA content among the treatments was not significant, and the promoting effect of SS content was also significantly reduced, but the inhibiting effect of SP content was still continuous. The contents of soil microbial biomass carbon and biomass nitrogen increased significantly, which increased with the increment of litter dosage, and decreased slowly along the time. Therefore, allelochemicals decomposed from C. camphora litter leaves would act in two ways:on the one hand, it affects the accumulation of osmotic regulation substances, such as soluble protein, soluble sugar in crops, on the other hand, it affects the available nutrient supply by changing soil microbial biomass. Finally, it had a significant influnence on the vegetative growth and biomass accumulation of crops.

Abstract:In order to understand the effects of aluminum on growth and physiological characteristics of alfalfa (Medicago sativa) seedlings, the above-and under-ground biomass, contents of leaf chlorophyll and callus in root tips were measured, the structure of root tips was observed, and the aluminum resistance of alfalfa was evaluated using membership function analysis. The results showed that with increment of aluminum concentration, the above-and under-ground biomass of alfalfa decreased, which significantly decreased under low and high aluminum concentrations (P<0.05). With increment of aluminum stress, the chlorophyll content of alfalfas dropped, while the accumulation of calluses increased, particularly under middle and high aluminum stress. Under aluminum stress, the cells of root tip had a big changes, which collapsed and in disorder under high aluminum stress. According to comprehensive evaluation, the aluminum resistance of No. 12 and No. 18 was better than that of others, suggesting that they could be applied in acid aluminized soil in southern China.

Abstract:In order to explore the effects of Piriformospora indica on seed germination and protocorm growth of Dendrobium officinale, the morphological and physiological characteristics were studied inoculated by P. indica on seeds and protocorm. The results showed that the initial germination time of D. officinale seeds inoculated with P. indica was earlier than the control, and the height, fresh weight, dry weight, number of leaves, leaf length, leaf width, root number and root length of protocorm of D. officinale inoculated with P. indica were higher than the control. The seed germination rate was 68.8% after 60 days of inoculation, which was higher than the control (28.6%). The chlorophyll a content, chlorophyll b content and total chlorophyll content in the protocorm of D. officinale inoculated for 80 days were significantly higher than the control, chlorophyll a/b was lower than the control, the net photosynthesis rate, stomatal conductance and transpirationrate were higher than the control, and the content of medicinal polysaccharide was significantly higher than the control. Therefore, the seed germination and protocorm growth of D. officinale were promoted by inoculation, and the quality and yield were improved.

Abstract:To provide the suggestion for pesticide application in snow fungus (Tremella fuciformis) cultivation, eight pesticides were used under spraying mode in different periods. The effects of pesticides on snow fungus strain Tr01 growth and health risk assessment of dietary exposure were studied. The results showed that all pesticides except prochloraz cream and pyridaben/acetamiprid microemulsion had not significant effects on growth of snow fungus. The level of pesticides residue was closely related to the type of pesticide and spraying mode. While the pesticide residue were below the corresponding MRL adopted from GB 2763-2019, the cHQ (chronic hazard quotient) of long-term dietary exposure for general population and young child ranged from 0.001 to 0.174 and 0.002 to 0.191, respectively. It indicated that the risk was acceptable. Based on the risk assessment, it was recommended for snow fungus cultivation that acephate, chlorpyrifos, and carbofuran should be banned, the use frequency of abamectin, prochloraz, and isoprocarb should be gradually reduced, and bifenthrin, acetamiprid, imidacloprid, and pyridaben could be used with the appropriate pre-harvest interval. These might be useful for designing good agricultural practices (GAP) and registering pesticide for snow fungus cultivation.

Abstract:In order to understand the effect of illumination on the expression of glucosyltransferase gene in Bougainvillea glabra, the cyclo-DOPA-5-glucosyltransferase gene (cDOPA 5GT) was cloned from bracts. The results showed that the full length cDNA of cDOPA 5GT was 1 446 bp, encoding 482 amino acids. The bioin-formatics analysis showed that isoelectric point of cDOPA 5GT was 5.77, showing an acidic and hydrophilic transmembrane protein without signal peptide. The cDOPA 5GT protein had characteristic motifs of glucosyl-transferase, and the secondary structure was dominant of α-helices and random coils, and the amino acid sequence was less conserved. The results of qRT-PCR and spectrophotometry showed that the expression of cDOPA 5GT gene and betacyanin accumulation in plants decreased significantly under shading by qRT-PCR and spectro-photometry. Therefore, it was suggested that the synthesis of betacyanin was regulated by glucosyltransferase gene, and positively correlated with light time.

Abstract:The fruit morphology of genus Trigonotis is taxonomically important, which plays important role in the delimitation of its sections. The fruit morphology of T. funingensis, however, is still lacking. Therefore, its taxonomic placement at section level remains unknown. In a field exploration, the mature fruits of T. funingensis were collected in Napo County, Guangxi, China. The fruit morphology of T. funingensis was supplemented based on the detailed examination under dissecting microscope and scanning electron microscope (SEM). Mature nutlet of this species is inverted subulate, trigonous-tetrahedral, and sessile, with three adaxial surfaces subequal in size and abaxial surface triangular. The nutlet morphology indicated that T. funingensis should belong to sect. Elongatae Ohwi.

Abstract:Two Astrochapsa species, A. pseudophlyctis and A. zahlbruckneri, are reported from China for the first time based on the morphological, anatomical and chemical characteristics. Astrochapsa pseudophlyctis is characterized by the crustose thallus with a compact surface, rounded to angular apothecia in outline, hyaline and muriform ascospores sized 30-75 μm×10-25 μm, and absence of lichen compounds detected. Astrochapsa zahlbruckneri is characterised by the crustose thallus, usually angular-rounded to irregular apothecia in outline with a strongly raised, jagged to typically lobed, upright to recurved margin, hyaline or slightly brownish and densely muriform ascospores (55-90 μm×22-28 μm), and presence of stictic acid.

Abstract:Anthoxanthum flexuosum (Hook. f.) Veldkamp, previously known from Bhutan and India, is a new record species in Xizang, China. Andropogon virginicus L., a native species in America, is naturalized in Jiangxi, China. A detailed morphological description, colorful plate as well as distribution and habitat information of these two grasses are given. Furthermore, the invasion risk of A. virginicus L. is also discussed.

Abstract:In oreder to understand the effective substances of water extract from Chrysanthemum morifolium flowers, its chemical constituents were identified by high-pressure liquid chromatography-high resolution mass spectrometry. The results showed that 376 chemical components were identified from flower water extract, and the relative content of 152 components were more than 0.1%. The components with high relative content included gypenoside XXVII, mimosine-O-β-glucoside, methyl-β-glucoside, d-1-O-methyl mucoinositol, l(+)-bornesitol, lucidol, methyl-β-galactoside, methyl-α-fructoside, ononitol, pinitol, (E)-2-hexenyl-α-arabinosyl-(1→2)-β-glucoside, miserotoxin, and so on. Therefore, the maim constituents in flower water extract of C. morifolium were flavonoids and alkaloids, which had 40 and 53 kinds with relative content of 22.68% and 26.57%, respectively, indicating that the main material basis for the performance of C. morifolium flowers.

Abstract:To clarify the chemical constituents in the leaves of Averrhoa carambola (Oxalidaceae), eleven compounds were isolated by means of organic solvent extraction and fractionation as well as diverse chromato-graphic separation techniques. On the basis of spectroscopic data, their structures were identified as phenyl β-d-glucoside (1), 3,4,5-trimethoxyphenyl β-d-glucoside (2), benzyl β-d-glucoside (3), 2-phenethyl rutinoside (4), 1-O-(3,5-dimethoxy-4-hydroxybenzoyl)-β-d-glucose (5), 5-hydroxymaltol (6), maltol β-d-glucoside (7), maltol 3-O-[6-O-(3-hydroxy-3-methyl-5-butylglutaroyl)]-β-d-glucoside (8), ethyl β-d-fructofuranoside (9), butyl β-d-fructofuranoside (10), and squalene (11), respectively. Compound 8 was a new artifact, and the others excluding 2 and 3 were obtained from the genus Averrhoa for the first time. Some compounds were related to the anti-inflammatory, antioxidant, and anti-tumor effects of the leaves.

Abstract:Coffee, one of the three top drinks in the world, belongs to Coffea (Rubiaceae), which can reduce blood sugar, protect liver and neuro. The chemical constituents of coffee are rich, including alkaloids, phenolic acid, flavonoid, terpene, etc. The chemical constituents are the basis of biological activities and forming the characteristic flavor of coffee. The main chemical constituents and biological activities of coffee were comprehensively reviewed, which would provide relevant basis and theoretical support for the further development of coffee industry.