Abstract:Ipomoea cairica is a notorious weed which has serious harm to the environment in South China. The effects of three chemical herbicides, such as 2,4-D butylate, dicamba and fluroxypyr, on control of I. cairica in the field were studied. The results showed that 2,4-D butylate (1.00 mL L^-1) could eradicate this weed. The death rate of I. cairica stems and leaves was close to 100% after spraying 2,4-D butylate (1.00 mL L^-1) in 20 days. The total biomass also decreased significantly in 60 days (P<0.05), and the growth did not recovery after 90 days. The final control effect of 2,4-D butylate (1.00 mL L^-1) on Ipomoea cairica was 99.8%. After spraying dicamba (1.00 mL L^-1) and fluroxypyr (1.00 mL L^-1) in 40 days, the death rate of I. cairica stems and leaves were 99.0% and 100%, respectively, and the regeneration rate of I. cairica was 10% and 100% after 90 days. A few roots were survival sprayed dicamba (1.00 mL L^-1) after 40 days. The herbicide residue analysis showed that 2,4-D butylate could degrade quickly with half-life for 14 days, and it could not be detected in the soil after 80 days. Furthermore, 2,4-D butylate (1.00 mL L^-1) was relatively safe to other plants, which could regenerate after spraying 2,4-D butylate in 1 year. Therefore, it suggested that the Ipomoea cairica growth could be good control treated with 1.00 mL L^-1 2,4-D butylate.

Abstract:The geographical distribution of wild resources of Dracaena cambodiana in China was comprehensively investigated and its relationship with climatic factors was analyzed by climate indexes, such as Kira’s warmth index, Xu’s humidity index, et al. The results showed that D. cambodiana was endemic to southwestern mountains and southern coastal areas of Hainan Island in China, with horizontal distribution from 108°42'40.9" to 110°27'36.8"E, and 18°14'27" to 19°20'28.5"N, and vertical distribution at 0-900 m altitude, and only ten distribution locations were found. The D. cambodiana is a small tree species of tropical rainforest or monsoon forest with ecological habitats of drought tolerance and heliophytes and calcicole, and most of hydrothermal factors were the main limited factors to its geographical distribution. The principal component analysis showed that the dominant factors on the distribution of D. cambodiana were in order as thermal factors > precipitation factors > relative humidity factors. Based on the habitat characteristics of wild populations, it suggested that both moisture and light intensity have significant effects on seed germination and seedling survival of D. cambodiana.

Abstract:The seed dispersal pattern, spatial distribution characteristics and seed bank dynamics of Terminalia franchetii in Dry-hot Valley of Jinsha River were investigate by random sampling and follow-up survey. The seed dispersal pattern had obvious direction influenced by strong wind, and the dispersal distance was more than 1.6 times of tree height. There was significant difference in soil seed bank among the different community types, but the change trends were consistent during different time. The soil seed bank was relatively small in rainy season (June, August, and October), and it was gradually increased from December to April of next year. The canopy seed bank started to shed in October, and reached to peak in March of next year (more than 15% of seeds shedding), and then the seed shedding rate became slow again, and seed shedding rate was the lowest in June and July of next year. However, there were nearly 15% of seeds existed in the canopy until October of next year. In summary, the lack of seed sources should not be the reason of T. franchetii seedling regeneration failure, and it might be associated with other factors which influence the community natural regeneration, such as the quality of seeds and community environment. Simultaneously, T. franchetii soil seed bank was closely related to the shedding process of canopy seed bank. Canopy seeds shedding might be closely related to the climatic factors, and might be a positive correlation with wind power, and be a negative correlation with rainfall and relative humidity. This might be an adaptive characteristic to Dry-hot valley environment in a long time.

Abstract:The bryophytes community in valley area of upper reach in Maotai, Guizhou Province, China was studied. The results showed that there were 116 bryophytes taxa belonging to 53 genera and 30 families. The bryophytes could be divided into 6 types, such as petrophytia, terrestrial, psammophytic, epiphytic, saprophytic and aquatic. Principal components analysis (PCA) showed that distribution pattern of bryophytes had significant difference affected by microenvironment factors. Isopterygium albescens, Weissia platyphylloides, Trichostomum brachydontium, Ptychomitrium dentatum, Brachythecium salebrosum and Campylopus subfragilis are dominant bryophytes, and their biomass ranged from 32.80 to 225.00 g m^-2 with saturated water absorption from 23519.90 to 269999.96 g m^-2. It suggested that the bryophytes could play important roles in the process of soil and water conservation, material recycling, improvement and replace of soil in valley area of upper reach in Maotai.

Abstract:The effects of sod cultivation in orchard on distribution of organic carbon in soil aggregates were investigated, which located in Yuchi Village, Youxi Xian, Fujian Province. The results showed that compared with downslope and landings clean tillage orchards, the proportion of >0.25 mm water-stable aggregate (R_0.25), mean weight diameter (MWD), and geometric mean diameter (GWD) of soil aggregate at 0-20 cm soil layer in sod cultivation orchard increased by 3.78%-5.90%, 16.82%-20.94%, 5.86%-50.31% and 3.81%-13.82%, 13.33%- 19.95%, 7.50%-60.63%, and the fractal dimension decreased by 1.54%-2.35% and 1.09%-9.64%, respectively. The sod cultivation could improve proportion of organic carbon storage in large aggregates (>2 mm) to total organic carbon at 0-20 cm soil layer. Therefore, the sod cultivation was beneficial to improve stability of soil aggregate, and could enhance the protection of organic carbon and carbon sink in soil.

Abstract:Using RACE and RT-PCR techniques, a novel member of WRKY gene family, named as HbWRKY1, was isolated from H. brasiliensis. Bioinformatics analysis showed that the full length cDNA of HbWRKY1 was 1234 bp, containing a 912 bp open reading frame and encoding 303 amino acids. The deduced amino acid sequence was highly homologous to WRKY proteins from Ricinus communis and Populus tremula × P. alba by 79% and 73%, respectively. The HbWRKY1 was constructed into pCAMBIA1304 expression vector, and transformed into tobacco (Nicotiana tabacum) mediated by Agrobacterium. Sixty-five hygromycin B (Hyg) resistant regenerated plantlets of tobacco were selected. PCR detection indicated that all the Hyg resistant tobacco plants contained the alien HbWRKY1 gene. It confirmed that the over-expression of HbWRKY1 under drought stress could obviously enhanced drought-tolerance of transgenic tobacco plantlets. Therefroe, it suggested that there were relationship between WRKY gene and drought tolerance of Hevea brasiliensis.

Abstract:The in situ PCR technical system on chromosomes of Hevea brasiliensis was developed successfully. The HbMyb1 gene related with Tapping Panel Dryness (TPD) resistance was physically located in the long arm of chromosome No. 5 of ‘Reyan 7-33-97’ by in situ PCR and the fraction-length, the percentage of the distance from detection site to the centromere, was 15.21. One or two signals were detected during cell division at different phases. The chromosome preparations, preservation, and pretreatment were also discussed.

Abstract:The full-length cDNAs of phosphoenolpyruvate carboxylase gene pepc were cloned from cassava (Manihot esculenta) cultivar Arg7 and wild species (M. esculenta subsp. flabellifolia) W14 by using Nest-PCR method, respectively, with corresponding GenBank accession number of JN387053 and JN387052. Both of two cDNA sequences were 2945 bp in length including a ORF of 2895 bp, predicting to encode a protein with 964 amino acids and containing typical conserved sequences/domains of pepc gene. Cassava PEPC had high homologous with that in Ricinus communis and Jatropha curcas. The pepc expression was the highest in leaves of W14 and Arg7, followed fibrous roots and tuberous roots, and the lowest expression was in stems. The oneday dynamic expression analysis showed that the pepc expression in Arg7 leaves was higher than in W14 before 16∶00, while it was higher in W14 than Arg7 after 16∶00. Therefore, it suggested that the regulatory regions of pepc gene in two cassava species were different.

Abstract:The insect resistances and evaluations on important agronomic and economic characters of 6 Bt-transgenic sugarcane lines, such as Y2, Y3, Y4, T1, T2 and T3, were studied both in the field and room. The results showed that the insect resistances of these Bt-transgenic sugarcane lines in the field were similar to those in the room, and the Bt gene expression was stable. All of these tested lines had stronger insect-resistance than their wild types, in which Y4 and T2 lines were the strongest and T3 line was the weakest. The cane yield and sugar content in Y3, Y4 and T3 lines were similar to those in their relative original lines, but the sucrose content of these transgenic lines was lower than that in original lines. In addition, although T2 line had higher sucrose content than original line ‘ROC16’, its main agronomic traits were worse with low cane yield and sugar content.

Abstract:In order to accelerate or delay fruit ripening and improve fruit quality, two early mature litchi cultivars, Litchi chinensis Sonn. ‘Sanyuehong’ and ‘Shuidong’, were treated with L-glutamic acid (Glu) and Thidiazuron (TDZ) at 50 days after blossom, the coloration and quality of fruits were determined. The results showed that Glu could promote fruits turning red. As the concentration of Glu (500-1500 mg L^-1) increased, the red area and anthocyanin content in fruit pericarp increased. Treated with 1500 mg L^-1 Glu, the anthocyanin contents in ‘Sanyuehong’ and ‘Shuidong’ pericarp were 8.62 U g^-1 and 11.53 U g^-1, respectively, which were 1.33 and 1.25 folds to control. Glu promoted total sugar accumulation in ‘Sanyuehong’ fruits, but had little effects on fruit size and weight of two cultivars. Fruit coloration was retarded with TDZ treatment, and anthocyan content was decreased at harvest stage. After treated with 5.0 mg L^-1 TDZ, anthocyanin contents in the ‘Sanyuehong’ and ‘Shuidong’ pericarp were 1.23 and 3.4 U g^-1, respectively, which significantly lower than those in control. After treated with TDZ, the total soluble solid and sugar contents in fruits decreased, but the fruit size and weight increased. Therfore, litchi fruits sprayed with L-glutamic acid on the 50^th day after blossom could accelerate maturation, but TDZ delayed.

Abstract:Leaf anatomic structure of Pueraria lobata (Willd.) Ohwi (Leguminosae) was observed under light and scanning electron microscopes. The results showed that both adaxial and abaxial epidermis only consist of one layer of cell. The adaxial epidermis was thicker than abaxial epidermis. There are glandular and nonglandular trichomes on both epidermis. The stomata were mainly distributed on abaxial surface with density of (261±17) mm^-2, compared to (6±3) mm^-2 on the adaxial epidermis. The mesophyll consist of two layers of palisade parenchyma cell and one layer of spongy parenchyma cell, both are rich in chloroplasts. There was one layer of parenchyma cell exit between palisade tissue and spongy parenchyma tissue. Many calcium oxalate crystals distributed in venation. The morphological characteristics of Pueraria lobata leaves were helpful to adapt to heliophytic and xerophytic environment.

Abstract:The mature pollen of Doritis pulcherrima is two-celled. The pollen began to germinate after pollinated one day. After pollinated five days, the division of generative cell occurred in pollen tube and formed a pair of sperm cells. The pollen tubes were induced to development in the ovary after artificial pollination and sperm cells were isolated from the tubes by immediately blowing up in a broken solution containing 5%-12% mannitol. The two sperm cells isolated were dimorphism, one was big and the other small, and the fluorescent intensity was distinctly different. It suggested that both sperm cells would have different futures.

Abstract:Camellia grandibracteata, a species extirpated about ten years, was rediscovered around its type locality. The description ‘ovariis 5-locularibus glabris’ in the protologue does not match the type specimens which show that its ovary is 3-5-loculed and puberulent in different degree. A morphological amendment was presented here.

Abstract:Carex trongii K. K. Nguyen (Cyperaceae) is reported as a newly recorded species from Guangxi, China. It grows under the forest in the limestone hills at 900-1000 m. It resembles the plants in Carex sect. Siderostictae Ohwi, but differs by its central culms and densely hispid perigynia. Further study on its position is necessary. The description and illustration of Carex trongii K. K. Nguyen are provided.

Abstract:Nine compounds were isolated from the ethanolic extract of roots of Atalantia buxifolia (Poir.) Oliv. by means of chromatographic technology. On the basis of spectral data, their structures were identified as buxifoliadine A (1), 1,3-dihy-droxy-2,4-diprenylacridone (2), 5-hydroxy-N-methylseverifoline (3), buxifoliadine B (4), N-methylatalaphylline (5), atalaphylline (6), atalafoline (7), aurapten (8), and coniferyl aldehyde (9). Compound 9 was isolated from the roots of A. buxifolia for the first time. Compounds 1 and 8 showed cytotoxic activities towards human hepatoma (SMMC-7721), and compound 3 showed significant inhibitory activity towards chronic myelogenous leukemia (K562).

Abstract:Nine compounds were isolated from the ethanolic extract from the whole plant of Elephantopus tomentosus Linn. On the basis of spectral data, their structures were identified as epifriedelanol (1), lupeol (2), 6-deoxyisojacreubin (3), butulinic acid (4), ursolic acid (5), ferulic acid (6), 3-formylindole (7), pinellic acid (8) and 30-oxo-lupeol (9), respectively. All compounds were obtained from Elephantopus tomentosus for the first time. Compounds 6 and 7 had inhibitory effect on Staphylococcus aureus, as well as compounds 6 and 8 exhibited inhibitory effects on Ralstonia solanacearum by paper disk diffusion method.

Abstract:Triarrhena lutarioriparia L. Liu is a kind of perennial herbaceous plant with high cellulose content. It has aroused high attention by related industries for its specific ecological adaptability, wide uses and productive development potential. In order to promote the comprehensive application and intensive research, the resources distribution, biological characteristics, breeding and cultivation technique of Triarrhena lutarioriparia were summarized, and the application of cellulose was also prospected.