Abstract:Coastal blue carbon mainly refers to the carbon sequestrated by the blue carbon ecosystems, such as mangroves, salt marshes, and seagrass meadows, which plays a vital role in mitigating climate warming. Salt marshes, the largest coastal wetlands in China, have been greatly affected by anthropogenic activities in the past several decades. However, there is still a lack of data synthesis of existing estimations and observations on carbon storage and sink of the salt marshes in China. Here, we systematically reviewed the distribution of salt marshes, carbon storage, carbon burial, carbon sources, and greenhouse gas fluxes in China. The distribution of salt marshes in China was (1.27-3.43)×10⁵hm², the soil organic carbon storage of salt marshes in China was (7.5±0.6) Tg, the carbon burial rate was 7-955 g C/(m²·a), and the greenhouse gas fluxes were 23.6-986 μg CH₄/(m²·h) and 1.58-110 μg N₂O/(m²·h), respectively. The research on the carbon cycle of Chinese salt marshes still needs to deepen the understanding of carbon sequestration mechanism and key regulators, so that salt marshes can make a greater contribution to the strategies of carbon neutrality in China.

Abstract:Photorespiration is a process, in which plant green tissue absorbs O₂ and releases CO₂ depending on light energy, which is considered to be a waste of energy. Photorespiration of normally growing C₃ plants can lose 25%- 30% of photosynthate, and the loss can be as high as 50% under stresses, such as drought, high temperature and high light. Therefore, significantly improving the productivity of C₃ plants can be achieved by reducing photorespiration flux. Although photorespiration has obvious negative effects on plant productivity, it may play an important role in some essential physiological activities of plants, including participating in photoprotection, H₂O₂ signaling, nitrogen metabolism, photooxidation and stress response. Thus, the transformation and optimization of photorespiration need to grasp the balance point and adaptation. The photorespiration modification based on Rubisco modification, CO₂ concentration mechanism (CCM) and photorespiration branch creation was reviewed. By understanding the latest progress in the regulation of photorespiration to improve the efficiency of plant light conversion, it is expected to provide guidance for the studies on molecular regulation and improvement of photorespiration metabolism.

Abstract:As one of the most important crops in the world, soybean provides more than 71% and 21% of the global consumption of vegetative protein and oil, respectively. As the increasing of population and the demand for soybean consumption, the genetic improvement of soybean quality has become more importance under the limited arable land area and yield per unit area. The research progress of the two important quality traits of soybean seed protein and oil contents was reviewed, the key enzymes and transcription factors controlling soybean protein and oil synthesis, and the interactions among different factors were summarized. The molecular regulatory network of soybean protein and oil synthesis was mapped according to the key enzymes and transcription factors in the pathway of protein and oil anabolic regulation. In addition, the current bottlenecks in soybean seed protein and oil improvement and the potential breeding strategies were discussed for providing understandings for the genetic improvement of soybean seed protein and oil.

Abstract:Hemerocallis, known as the mother flower of China, is a perennial root flower with important ornamental and medicinal values. Abiotic stresses lead to reduced photosynthetic efficiency, altered concentrations of osmoregulatory substances, increased levels of reactive oxygen species (ROS) and sustained damage to the membrane system, inducing the expression of gene families such as AP2/ERF and WRKY. The effects of drought, flooding, salinity, extreme temperature and heavy metal stress factors on the morphology, physiology, biochemistry and molecular level of Hemerocallis were reviewed, and the resources of Hemerocallis resistance cultivars under various stresses were counted. It was proposed that the effects of region and stress on the metabolic changes of medicinal components of Hemerocallis, the regulatory network of stress-related genes and multiple stress complex molecular breeding should be the key research directions in the future. It would provide a theoretical reference for the development and utilization of Hemerocallis resources and breeding of resistant varieties.

Abstract:In the context of global climate change, drought has become one of the major abiotic stresses limiting crop yield and quality worldwide, which causes huge losses to the global society, economy and ecology. Hence, it is increasingly critical to enhance the drought resistance of plants. Numerous studies at domestic and abroad have confirmed that silicon can promote plant drought resistance. For example, the application of exogenous silicon can improve water status of plants by affecting the stomatal conductance and changing the transpiration rate; silicon can also improve photosynthesis by regulating stomatal dynamics, synthesizing photosynthetic pigments and promoting photochemical reactions; in addition, silicon can not only balance the absorption and utilization of minerals by plants through osmotic adjustment but also regulate the antioxidant defense system to reduce the oxidative damage of plants under drought stress. Here, we systematically summarize the effects of silicon on plant water utilization, photosynthesis, mineral absorption, antioxidant systems, plant hormone metabolism and related physiological mechanisms under drought stress. It was suggested that the mechanism by which silicon enhances drought resistance of plants should be revealed from the aspects of combined stress and low silicon accumulating plants in the future, so as to provide a scientific basis and lay a theoretical foundation for the rational use of silicon in agroforestry ecosystems to improve production efficiency.

Abstract:Calcium (Ca²⁺) is an important second messenger in plants. The intracellular concentration of Ca²⁺ is often elevated instantaneously under various kinds of biotic and abiotic stresses, and which is recognized by Ca²⁺ signal effectors. By binding to downstream target proteins and regulating their activities, Ca²⁺ participates in the regulation of various physiological activities of plants. Calmodulin binding proteins bind calmodulin in a Ca²⁺-dependent or Ca²⁺-independent manner. The structure characteristics of calmodulin binding proteins identified in plants were reviewed, and emphasizing on how calmodulin binding proteins are involved in regulating plant responses to biotic and abiotic stresses was focused, which would provide a theoretical basis for study of improve disease-tolerance and stress-tolerance of crops.

Abstract:Strigolactone (SLs) as a new group of plant hormones, plays a variety of crucial functions in plant growth and development, including regulating plant branching, promoting seed germination, and affecting root system formation. MAX2 (more axillary growth 2) is a key regulator of SL signal transduction pathway. It is located downstream of the synthesis pathway genes MAX1, MAX3 and MAX4, and affects almost all phenotypes controlled by SL_S. In recent years, the diversified functions of MAX2 have been gradually revealed. A large number of data show that MAX2 is not only an important component of SL signal, but also involved in the cross interaction between SL and a variety of hormone signals, which plays a vital role in all aspects of plant growth and development, as well as in the response to biotic and abiotic stresses. However, the specific regulation mechanism still needs to be further studied. The current known functions of MAX2 were summarized and elaborated, in order to provide theoretical reference for fully revealing the function of MAX2 and the cross- mechanism of regulating various hormone signals.

Abstract:In order to understand the adaptation of Gahnia tristis in the red soil erosion zone of southern China, the functional traits of leaves and roots of G. tristis, and the physicochemical properties of soil were determined and their correlations and the responses of leaves and roots of G. tristis to soil factors were analyzed by using mathematical statistics method. The results showed that there were significant differences in phenotypic traits of Gahnia tristis leaves between winter and summer, leaf length, leaf width, leaf tissue density and chlorophyll content were significantly higher in summer than those in winter, while the root phenotypic traits were more stable. The nutrient content of roots in winter was higher than that in summer, and the nutrient allocation in leaves was higher than that of roots. Leaf tissue density had positive correlation with chlorophyll content and negative with specific leaf area. There was significant negative correlation between root tissue density and specific root length and specific root area, and significant positive correlation between leaf and root nutrients. Soil carbon, nitrogen, and phosphorus contents were the main factors affecting the functional properties of G. tristis. Therefore, it was suggested that G. tristis could adapt to environmental changes by adjusting its functional traits, which could be used as a zonal plant for vegetation restoration and soil erosion control in the red soil erosion areas of south China.

Abstract:In order to understand the ecological adaptability of plant species to high temperature, intense radiation and deficit soil in tropical coral islands, the differences of leaf functional traits and the ecological strategies among different life forms of plants grown on coral island were studied. The results showed that there were significant differences in total N, cellulose concentrations, leaf C/N ratios, water use efficiency and specific leaf area among the life forms, and there were significant correlations among leaf function traits, indicating trade-offs between resource allocation and growth investment of the plants. Plant species exhibited significantly different and divergent ecological strategies grown in the coral islands. In the practice of vegetation restoration in coral island, plant species like Pisonia grandis and Tournefortia argentea could be preferentially adopted, but herb like Wollastonia biflora, Chromolaena odorata and Sphagneticola trilobat should be strictly monitored to avoid their expansion.

Abstract:Phaeocystis globosa is a common harmful algal bloom species in the Beibu Gulf in recent years. As one of the areas with high frequency harmful algal blooms in Guangxi coast, there are seldom study on the P. globosa blooms in Weizhou Island. In order to investigate the status of nutrient and the effects of P. globosa blooms on phytoplankton community near Weizhou Island, a sampling survey was conducted on the area of P. globosa bloom occurred around Weizhou Island in late March 2017. The results showed that dissolved organic phosphorus (DOP) content had significantly positive correlation with the cell and colony density of P. globosa during the bloom. The bloom was mainly affected by the dissolved inorganic nitrogen (DIN), the ratio of DIN to dissolved inorganic phosphate (DIN/DIP) were lower than 10 in many stations, while the ratio of dissolved silicate to DIN (DSi/DIN) were higher than 1, indicated that nitrogen limitation existed in these areas. Nitrogen limitation was thought to be a major factor during the bloom’s demise. There were 58 species in 4 phyla of phyto- plankton identified in the survey area. The maximum abundance of P. globosa reached 1.04×10⁸ cells/L, accounted for 98.28% of total phytoplankton. There was a significantly negative correlation between the abundance of P. globosa and the species diversity index. In addition, under nutrient deficient condition, species of diatoms with chainlike structure which were beneficial to the formation of P. globosa colony had relatively greater abundance.

Abstract:To understand the variation characteristics of timber traits among Chinese fir (Cunninghamia lanceolata) families, the phenotypic diversity analysis and comprehensive evaluation of 10 growth indexes of 14 families were studied by using methods of variance analysis, cluster analysis, principal component analysis. The results showed that the phenotypic diversity indexes of 10 main timber traits in 14 families ranged from 1.438 to 2.008 with an average of 1.735, among which the highest was height, and the smallest was tracheid length. The phenotypic diversity was rich, height, diameter at breast height, volume, length-width ratio and green density had strong genetic variability, and there was a certain correlation among traits. The family heritability (H²) ranged from 0.012 to 0.934, the largest was length-width ratio, and the smallest was green density. The phenotypic variation coefficient varied from 3.81% to 39.90% with an average of 15.03%, the biggest and smallest were volume and tracheid cavity to width ratio, respectively, indicating that the genetic improvement potential was great. The 14 Chinese fir families could be divided into three major groups, group III had the best comprehensive traits, and group I had the best growth. The top 3 families for growth traits were JX3, JX10, JX2. Therefore, the phenotypic diversity of the 10 main timber traits was rich, and the top 3 families could be used as excellent materials for the conservation and efficient utilization of Chinese fir germplasm.

Abstract:To investigate the chemical constituents from rhizomes of Panax zingiberensis, nine compounds were isolated and purified by methods of column chromatography on silica gel and Sephadex LH-20. Based on physical and chemical properties and spectral data,their structures were identified as ginsenoside SL₁ (1), ginsenoside Rh₁ (2), notoginsenoside R₈ (3), chikusetsusaponin IVa (4), vina-ginsenoside 10 (5), ginsenoside Rg₁ (6), spinasaponin A 28-O-β-d-glucopyranoside (7), oleanolic acid 28-O-β-d-glucopyranoside (8) and zingbroside R₁ (9). Compounds 1, 3, 5, 7, and 8 were isolated from P. zingiberensis for the first time. Compound 5 belongs to the ocotillol-type saponin, which was not previously reported from this species.

Abstract:To reveal the resources status of medicinal seed plants in Mao County, the floristic characters of medicinal seed plants in Mao County was studied based on the data of the 3rd and 4th Chinese materia medica resource survey. The results showed that there were 1 342 species of medicinal seed plants in Mao County, belonging to 582 genera and 130 families. Among them, there were 7 families, 14 genera, 18 species in gymnosperms, 123 families, 568 genera, 1 324 species in angiosperms, and national key protected wild plants had 18 families, 37 genera, and 57 species. Fifteen large families (containing more than 20 species) were dominant, accounting for 48.45% and 56.56% of the total genera and species, respectively, while small genus (including 2-4 species) had 507 genera and 783 species, accounting for 87.11% and 58.35% of the total genera and species, respectively. In terms of areal types, the tropical component was dominant at family level (56.52%), while the north temperate component was dominant (68.11%) at the genus level. Compared with neighboring areas, the flora of medicinal seed plants in Mao County showed more distinct temperate than that in Jiange County and Yanbian County, while the tropical component of Mao County was more active than that in source area of Lancang River and Cuona County, revealing that latitude and altitude might be the key factors in determining the floristic character of medicinal seed plants in Mao County. Therefore, the flora of Mao County medicinal seed plants not only had a high species diversity, but also had a certain degree of complexity of floristic geographical components, which was mainly reflected in the dominant temperate zone nature and also showed a relatively obvious transitional nature. MAO County could be regarded as one of the key areas for studying the north-south plant communication in Hengduan Mountain region. It was worth paying more attention to the diversity protection and exploitation of medicinal seed plants.

Abstract:A newly recorded species of China, Myriophyllum siamense (Craib) Tardieu (Haloragidaceae) found in Hainan Island, China was reported and described. The species is semi-aquatic, without pinnate leaves and with highly reduced male flowers. In terms of morphological characteristics, it is related to some species in Australia and Oceania, and provides evidence for the intercontinental spread of Myriophyllum. Its discovery also shows that there are still many weak areas and blind spots in Hainan Island.

Abstract:Bonia saxatilis var. danxiaensis, a new variety from Danxia Mountain National Nature Reserve is described and illustrated. It differs from the nominate variety by having ligules of both culm and foliage leaves without long cilia on the margin. The key to the varieties of Bonia saxatilis is provided here. We also emend the descriptions of some vegetative characters and provide a supplementary description of floral morphology for another species newly described from Danxia Mountain, Dendrocalamus pulverulentoides.

Abstract:Amomum pauciflorum Baker, a newly recorded species of Amomum s.s. (Zingiberaceae) from Ximeng, Yunnan, China is reported. The species is morphologically similar to A. longipetiolatum Merr., but can be distinguished by its wider corolla lobes and crescent anther crest (vs. trilobed). A detailed description, geographical distribution and color photoes are provided here. The voucher specimens are deposited in the Herbarium of Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences.

Abstract:The historical development, main achievements and social contributions of the South China National Botanical Garden were retrospected in several key periods of the past nearly one hundred years. In addition, the reasons for the establishment of South China National Botanical Garden from the respective respect of country, the Chinese Academy of Sciences, and the local government were analyzed. Finally, we discussed the development prospects of the South China National Botanical Garden and put forward some suggestions for the future construction of China’s national botanical garden system.