Abstract:The spatial genetic structure (SGS) is an important part of evolutionary ecological and ecological genetic processes in natural populations of plants. The spatial distribution patterns of genetic variation of two closely related sympatric Castanea species, C. mollissima and C. henryi, were investigated using seven microsatellite loci. A total of 173 alleles were detected in the two species. According to the isolation by distance model, Sp-statistics were calculated based on Moran's I spatial autocorrelation coefficient and F_ij kinship coefficient for the two species. The results showed that there were high polymorphism in each species with low genetic differentiation ( F_ST=0.051). However, the two species displayed significant difference of SGS in this sympatric population. Spatial genetic structure was detected in C. henryi up to 100 m, while that was not observed in C. mollissima. Moreover, the Sp-statistic values based on F_ij, were 0.002 for C. mollissima and 0.018 for C. henryi. These results further supported that C. henryi had stronger spatial genetic structure than C. mollissima. The difference of SGS in C. mollissima and C. henryi can be explained by different seed characteristics, as C. mollissima was charactertized by three nuts per cupule while there was only one nuts per cupule for C. henryi. Therefore, the long-distance seed dispersal via gravity and animals was much more favored for C. mollissima than C. henryi, which reduced different SGS between the two species.

Abstract:In order to understand the molecular mechanisms of rice responding to heavy metal stress, the structure characteristics and expression pattern of OsMTP2, a metal tolerance protein in rice, were studied by using bioinformatics method. The results showed that OsMTP2 was consisted of 415 amino acids with strong hydrophobicity. mRNA in situ hybridization experiment showed that OsMTP2 gene mainly expressed in leaf vascular bundle, while no signals were detected in roots and anthers. It suggested that OsMTP2 transcripts may mainly occure in transfusion tissues and play an important role in metal transport.

Abstract:The effects of sucrose, boron and calcium on the germination of Rhyncholaeliocattleya Sung Ya Green ‘Green World’ pollen were studied by orthogonal design experiment. The results showed that the optimum culture medium for pollen germination was 100 g L^-1 sucrose+40 mg L^-1 H₃BO₃ +150 mg L^-1 CaCl₂. Different storage methods had different effects on pollen viability of ‘Green World’. The pollen germination rate was only 3.5% humid stored under 4℃ for 30 days. However, after dry stored in 4℃, freeze-wetting and freeze-drying stored in-20℃ for 720 days, respectively, the pollen germination rate still maintained at high level, reaching up to above 32.5%, and there was not effect on seed setting. The best time for pollination was 0-8 days after flowering and the pollinium had high vitality during whole florescence.

Abstract:The total proteins in peels and leaves of Citrus reticuiata Blanco ‘Chuntianju’ were extracted by four methods, such as Tris-HCl, Thi/Urea, trichloroacetic acid/pacetone precipitation (TCA) and phenol (Phe) extraction methods, respectively, and their effects were compared by protein production, one-way SDS-PAGE and two-dimensional electrophoresis (2-DE). The results showed that TCA method was the best for both leaves and peels of C. reticuiata ‘Chuntianju’. The 2-DE map of proteins extracted by TCA method had high resolution, the protein spots were clear and uniform without stripes, and the number of protein spots were large. It suggested that the TCA method could not only remove the interfering substances in peels and leaves of C. reticuiata ‘Chuntianju’, but also get more stable protein spots.

Abstract:The hypocotyls of Jacaranda mimosaefolia used as explants, the tissue culture and rapid propagation system were studied. The results showed that the seed germination rate of J. mimosaefolia reached up to 55.6% after warm water immersion for 60 minutes at 40℃-45℃. The optimum mediums for induction of adventitious buds and callus were MS+6-BA 2.0 mg L^-1+NAA 0.1 mg L^-1+2,4-D 0.1 mg L^-1, and MS+6-BA 0.5 mg L^-1+NAA 1.0 mg L^-1+2,4-D 1.0 mg L^-1, respectively. The optimum mediums for proliferation of adventitious buds and callus were modified MS+6-BA 0.5 mg L^-1+NAA 0.5 mg L^-1+IBA 0.5 mg L^-1, and MS+6-BA 1.0 mg L^-1+ NAA 0.5 mg L^-1+ZT 3.0 mg L^-1, respectively. The optimum medium for callus differentiation was MS+6-BA 1.0 mg L^-1+NAA 0.5 mg L^-1+2,4-D 0.5 mg L^-1. The optimum rooting medium was 1/2MS supplemented with 20 g L^-1 sugar and NAA 0.5 mg L^-1 and 2.0 g L^-1 active carbon (AC) with rooting up to 78.3%.

Abstract:Stems, leaves, hypocotyls and radicles from aseptic seedlings of Ardisia crenata Sims. used as explants were cultured on different mediums to induce callus. The results showed that radicles of A. crenata cultured on mediums with 2,4-D had the highest callus inducation rate. The callus subcultured on MS +2,4-D 0.5 mg L^-1+KT 0.01 mg L^-1 supplemented with 5 mg L^-1AgNO₃ had more than 8 times proliferation coefficient. Five types of callus, such as white, wet and soft callus (I), white gibraltar-like callus (II), yellow granular callus (III), yellow green nubbly callus (IV), and green nubbly callus (V) were obtained. Among which callus II and III could successfully establish suspension cell system, and the callus could be well maintained cultured on MS+2,4-D 0.5 mg L^-1+KT 0.01 mg L^-1 by solid-liquid transition.

Abstract:The spore development and callus induction of Bryum dichotomum Hedw. in vitro culture were studied. The results showed that the spore germination and protonema development of B. dichotomum Hedw. were Bryum-type. The calli were successfully induced from protonema cultured on solid MS medium supplemented with 3.0 mg L^-1 6-BA and 2.0 mg L^-1 sodium silicate. The calli could be subcultured at long term on solid MS medium supplemented with 2.0 mg L^-1 sodium silicate, 1.0 mg L^-1 2,4-D and 1.0 mg L^-1 6-BA. The fresh weight of calli cultured for 28 days was about 9.25 times to original weight under suspension culture, when incubated in liquid MS medium supplemented with 2.0 mg L^-1 sodium silicate, 1.0 mg L^-1 2,4-D and 1.0 mg L^-1 6-BA.

Abstract:Genomic in situ hybridization (GISH) was used to detect the AA genome distribution of Eleusine indica (L.) Gaertn. on chromosomes of E. coracana (L.) Gaertn. (AABB), and the homoeologous relationship between AA and BB genomes was studied. The ultrasonic processor pre-sheared total DNA of E. indica further labeled by nick translation mix as probe and the sheared total DNA of E. floccifolia (Forssk.) Spreng. (BB) as blocking DNA, and then they were hybridized to the metaphase chromosomes of E. coracana. The results showed that the AA genome of E. indica was distributed in 18 chromosomes of E. coracana. When not adding or adding excess blocking DNA, the AA genome was not detected on the chromosomes of E. coracana, suggesting that the AA and BB genomes may have not yet been well differentiated from each other, and that E. indica and E. floccifolia may share abundant repeated sequences. The 300-750 bp fragment peaks were presented on the 1% agar gel after shearing total DNA of E. indica and E. floccifolia 2 min and 3 min, respectively. The difference in the time of DNA shearing of the two species suggests that the ultrasonic processor method should be adjusted depending on species in order to obtain DNA probes with appropriate lengths.

Abstract:Chromosome numbers and karyotypes in four populations of three species in the genus Ainsliaea DC. (Asteraceae-Pertyeae) from southern China have been investigated for the first time. The chromosome number of A. henryi Diels was counted to be 2n=24, and the karyotype was formulated as 2n=16m+8sm. The number of A. trinervis Y. C. Tseng was counted to be 2n=26, and the karyotype was formulated as 2n=16m+10sm. Both populations of A. ramosa Hemsl. had 2n=26 and the karyotype of 2n=22m+4sm. In all of the populations studied the chromosomes showed a steady gradation in length from the longest to the shortest, with no evidence of bimodality. The results have confirmed the occurrence of two basic chromosome numbers, x=12 and x=13, in the genus Ainsliaea, with x=13 very likely being the primitive number.

Abstract:Croton hirtus L'Hér. of Euphorbiaceae is reported as a naturalized species from China. Description and illustrations are provided. The voucher specimens are kept in the Herbarium of South China Botanical Garden, the Chinese Academy of Sciences (IBSC).

Abstract:Two newly recorded species of mycotrophic orchids from China, Cyrtosia integra (Rolfe ex Downie) Garay and Galeola cathcartii Hook. f. are reported. Brief descriptions and photoes of them are also provided.

Abstract:The population structure, spatial distribution patterns and the correlationship between environment factors and population density of natural Sinocalycanthus chinensis populations were studied. The results showed that there were abundant seedlings at most of investigated plots, which indicated natural regeneration of S. chinensis populations were good. The spatial distribution pattern of S. chinensis in plots was dominated by cluster. Under low light density and high canopy density community, the distribution of S. chinensis tended to high aggregation strength with poor population renewal and lack of seedlings. Therefore, S. chinensis is suitable for growing in opening shade environments, the protection measure of moderate intermediate cutting must be adopted in over crown closure forest so as to cutting upper layer trees and thinning close brushes.

Abstract:Carbon storage and spatial distribution characteristics of Dendrocalamopsis vario-striata were studied by using quadrat method.The results showed that carbon density in different organs of D. vario-striata ranged from 0.4684 to 0.5092 g g^-1, with in order as: culm>rhizome>root>branch>leaf. The organ distribution of carbon storage was 50.46% for culm, 20.71% for rhizome, 14.31% for root, 9.24% for branch and 5.01% for leaf. The total carbon pool, counting for 104.9321 t hm^-2, mainly consisted of four components, such as arbor layer, shrub and herb layer, litter layer and soil layer, which spatial distribution was in order as: soil layer (59.74%)>arbor layer (36.86%)> litter layer (2.30%)>shrub and herb layer (1.10%). Annual fixed carbon content of bamboo forest was 6.4460 t hm^-2, equivalent to 23.6353 t hm^-2 CO₂, which was lower than that of average value of forests in China. It suggested that there was much development space for fixed carbon capacity of D. vario-striata.

Abstract:Eleven triterpenoids were isolated from the leaves of Turpinia arguta (Lindl.) Seem. On the basis of spectral data, they were identified as ursolic acid (1), uncargenin C (2), 3β,6β,23-trihydroxyurs-12-en-28-oic acid (3), 3β,6β,19α,23-tetrahydroxyurs-12-en-28-oic acid (4), 1α,3β,23-trihydroxy-12-oleanen-28-oic acid (5), rosamultin (6), arjunglucoside II (7), 3β-O-β-D-glucopyranoylcincholic acid (8), cinchonaglycoside C (9),mussaendoside S (10),and 3β-O-β-D-glucopyranosyl quinovic acid 28-O-β-D-glucopyranosyl ester (11). All these compounds were obtained from T. arguta for the first time except compounds 1 and 6.

Abstract:Seven compounds were isolated from the ethanolic extract of twigs and leaves of Kopsia hainanensis Tsiang. On the basis of spectral data (NMR, MS, IR, etc.), their structures were identified as kopsinine (1), tubotaiwine (2), dihydrodehydrodiconiferyl alcohol (3), β-amyrin (4), ursolic acid (5), 2 α,3β-dihydroxyursolic acid (6), and β-sitosterol (7). Compounds 3-7 were isolated from K. hainanensis for the first time. Antibacterial activities assayed by paper disk diffusion method, the result showed that compounds 1-3, and 5 had inhibitory activities against methicillin-resistant Staphylococcus aureus (MRSA), and compound 2 exhibits inhibitory effect on Staphylococcus aureus. Cytotoxic activity assay demonstrated that compound 5 showed cytotoxic activities towards chronic myelogenous leukemia (K562), human gastric carcinoma (SGC-7901), and human hepatoma (SMMC-7721) cell lines.

Abstract:Seven chemical constituents from fruits of Aquilaria sinensis (Lour.) Gilg were isolated by column chromatography. Based on spectral analysis and physicochemical evidence, their structures were identified as: indolyl-3-carboxylic acid (1), 6-hydroxy-2-[2-(4-hydroxyphenyl)ethyl] chromone (2), genkwanin (3), 4',5-dihydroxy-3',7-dimet-hoxyflavone (4), apigenin-7,4'-dimethylethers (5), β-sitosterol (6), and daucosterol (7). Compound 1 was obtained from the genus Aquilaria of the family Thymelaeaceae for the first time.

Abstract:Endophytic bacteria play an important role in the life history of orchids,which influence the formation of mycorrhiza and stability of plant-fungi interaction. Endophytic bacteria could promote growth and development of orchids by secreting phytohormone, conducting photosynthesis, fixing nitrogen or promoting the cycle of mineral nutrition, producing siderophore and secreting other active substances. The research methods of the diversity of endophytic bacteria associated with orchids, and their growth-promoting mechanism were reviewed. Based on the close relationship between orchids and symbiotic microbe, the studies on interactions between endophytic bacteria and mycorrhizal fungi will be an important direction to reveal the mechanism of orchid-endophytic bacteria interaction.

Abstract:Phospholipase D (PLD) is an important phospholipid hydrolase prevalently existing in plant cells. PLD plays an important role in regulation of many critical cellular functions, including regulation of cell membrane reconstruction, cellular signal transduction, intracellular regulation, cellular backbone formation, defense responses, seed germination and plant senescence, etc. The basic characteristic of PLD, differential expression pattern of PLD gene and senescence-related physiological and biochemical processes involving PLD were comprehensively reviewed. The relationship between PLD activity inhibition and senescence was discussed, as well as the research direction of PLD gene in the future was prospected.