Guangxi Area Research Articles

Gleditsia saxatilis (Fabaceae), a new species from limestone areas of Guangxi, China based on morphological and molecular evidence

Gleditsia saxatilis Z.C.Lu, Y.S.Huang & Yan Liu, a new species was found from limestone areas of Guangxi, China. The morphological and phylogenetic analyses showed that G. saxatilis is similar to G. sinensis, but differs by its habit indeciduous, winter buds globose or subglobose, apex round, petiolules glabrescent to glabrous, leaflets 2–4 pairs, leathery, both sides glabrous, racemes shorter, 2.5–7 cm long, ovary glabrous, legume slightly falcate, stipe 3–8 mm long.

Primulina papillosa (Gesneriaceae), a new species from limestone areas of Guangxi, China.

Primulina papillosa Z.B. Xin, W.C. Chou & F. Wen, a new species from limestone areas of Guangxi, China, is described and illustrated here. It morphologically resembles P. linearifolia (W.T. Wang) Yin Z. Wang and P. pseudolinearifolia W.B. Xu & K.F. Chung, but can be easily distinguished by some combined characters, especially its leaf blades densely papillose-hispid. We found only one population at the type locality with no more than 200 individuals, so that this new species is provisionally assessed as Critically Endangered (CR) using IUCN Criteria.

Study on the Evolution of Guangxi Traditional Pile-Dwelling Architecture —— Take Baise, Guangxi as an example

With the development of history and the transformation and renewal of production methods, human construction activities will reflect the content of production activities at that time to a certain extent. Guangxi is located on the southeastern edge of the Yunnan-Guizhou Plateau, the second step in the topography of the country. Guangxi is located in the western part of the hills of Guangdong, Guangxi. The mountain area is vast, and it is a zone of communication between regions, ethnic groups, and countries. It has rich ethnic and regional cultural characteristics, and various architectural phenomena are splendid. Pile-Dwelling architecture is a traditional dwelling form of the Baiyue people, belonging to a “native” type of regional architecture. It has the innate advantages of using topography and striving for space, and is widely used in the mountainous areas of Guangxi. This paper will take Guangxi traditional dry fence architecture as the research object, and will conduct research on Guangxi’s traditional vernacular architectural culture. Through combing and researching the development of dry fence architecture in China, it will summarize the evolution law of Guangxi traditional Pile-Dwelling architecture, in order to protect Guangxi Zhuang’s architectural cultural heritage and providing a basis for regional architectural creation in Guangxi. It will be of great significance for achieving ecological harmony and promoting the construction of new towns.

Value chain analysis of yellow broiler industry in Guangxi, China to inform H7N9 influenza control strategies

Yellow broilers are the primary source of poultry consumption in China and the predominant trade of live poultry. However, knowledge of the value chain is limited, which is vital evidence for the effective control of H7N9 and other zoonotic avian influenzas. The aim of the study was to map the yellow broiler value chain in Guangxi Zhuang Autonomous Region, China and investigate its governance structure and practices relevant to the risk of H7N9 transmission.A value chain analysis was conducted in five areas of Guangxi from May to August 2018. To map the value chain, three focus group discussions (FGDs) were conducted and stakeholders, products and premises involved and their interactions were identified. Then, 55 key informant interviews (KIIs) collected qualitative data on stakeholders’ profile, practices and interactions with other stakeholders and rules/norms that exist along the value chain. On-site observations were also carried out at different types of premises along the value chain to complement and validate findings of KIIs and FGDs. Participants were also asked to provide proportional estimates of each component in the value chain where possible. The qualitative data from FGDs, KIIs and on-site observations were analysed to create stakeholder profiles and a diagram of product flows and stakeholders’ interactions. Thematic analysis was used to identify the governance structure of the value chains and practices relevant to the risk of H7N9 transmission.The stakeholders and premises involved in Guangxi yellow broiler production, wholesale and retail were described, as well as their interactions. Contract farming is extensively adopted in Guangxi; consequently yellow broiler grower companies are the dominant stakeholders. The trading platform was identified as a key premise linking farms and live bird markets. The thematic analysis highlighted poor biosecurity practices in different premises along the value chain, which was supported by on-site observations. The operation of trading platforms reported in this study presents a disease risk but is not considered in the current H7N9 control programs. The study suggested that biosecurity management gaps need to be addressed through government-industry partnerships that require engagement with private stakeholders in the planning and implementation of H7N9 control strategies incentivising participation of grower companies, wholesalers and retailers.

The Study on Normalization Mechanism of Consolidating Poverty Alleviation Achievements in China’s YunnanGuangxi Border Areas

For a long time, poverty reduction has been the focus of academic circles—scholars at home and abroad explain and explore the development law and spatial evolution of poverty from economics, ethnology, geography and other disciplines, and study poverty reduction practice, experience, population, and economic development. However, there are few research results from the perspective of defining the cross-border ethnic groups in Yunnan, Guangxi and Southeast Asia and consolidating poverty alleviation results. Yunnan-Guangxi border areas overcome various unfavorable conditions including natural environment, develop steadily, and get rid of poverty by the end of 2020. Although great progress has been made in the areas of politics, economy, society and people’s livelihood in the border areas of Yunnan and Guangxi, there are still complex domestic and international factors affecting the consolidation of poverty alleviation achievements in this area. In the future, it is necessary to strengthen the dynamic monitoring and mechanism construction of poverty alleviation, enhance the economic “hematopoietic function” of border areas, strengthen domestic and foreign cooperation and create a good border environment, so as to consolidate the hard-won poverty alleviation achievements and realize rural revitalization.

Influencing factors on transfer and bioaccumulation of soil cadmium and assessment of its environmental risk in a typical karst area, China

ABSTRACT Cadmium has become the foremost inorganic pollutant in farmland in China. It is widely accumulated in karst areas in southwest China, especially in Guangxi Province. In this study, vertical soil profiles, rice grains and corresponding root-soil samples were collected in Guangxi. The Cd contents of soil and rice grain samples and several soil properties, including organic matter, Fe2O3, Al2O3, CaO, MgO, SiO2 contents and pH were tested. Meanwhile, sequential extraction procedure were used to analysis the chemical fractions of Cd in root-soil samples. Based on the measured data, influencing factors on bioaccumulation of Cd and its contamination risk in study area were discussed. The results indicate that the bioaccumulation and mobility of Cd from soil to rice grain are restrained by high soil pH, high contents of organic matter, clay mineral and carbonate. Guangxi has strong development of karst landform, with the continuous process of soil formation, the activity of Cd in the soils in such areas will gradually become stable. In general, the environmental risk of soil cadmium contamination in karst areas of Guangxi is relatively low. But preventing soil acidification is the significant measure to prevent the environmental risk of it.

Population occurrence of the fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae), in the winter season of China

Fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith), has become an important pest in Chinese agricultural systems since its invasion on 11 December 2018. After its establishment, FAW months in the year-round breeding region have become the main source population migrating to other areas in China. Field investigations were conducted in tropical and subtropical regions to improve understanding of its year-round breeding area in China. The results showed that FAW larval density was significantly correlated with the seasonal temperature of the location surveyed. The FAW larvae maintained a high density in the tropical area and were frequently found in sites of the south subtropical region, but were absent from the north subtropical region and the northern part of the central subtropical region. These results indicated that FAW can reproduce annually in the tropical and south subtropical regions of China, including Hainan, Taiwan and the southern area of Fujian, Guangdong, Guangxi, Guizhou, and Yunnan. Hence, great effort should be made to monitor and control FAW in the year-round breeding region to suppress the population density of this area and to reduce migration of moths into northern parts of China. This study clarifies the occurrence area of the pest in winter in China and provides much valuable information for its population forecasting and management.

Study on Seismic Capacity of Single-story and Brick-concrete Structure Building in a Rural Area of Southern Guangxi

Based on the investigation and analysis of the brick-concrete and single-story houses in a rural area of southern Guangxi, the author established four different overall models of single-story house according to a certain proportion by ABAQUS-a software of finite element analysis, so as to analyze the seismic response of brick-concrete and single-storey buildings in this area under the action of 6-magnitude frequent earthquake. The results show that, under the action of 6-magnitude frequent earthquake, if the single-storey and brick-concrete house is built without reinforced concrete, its wood beam support or column support cannot reduce the stress concentration of the structure obviously;the displacement deviation between the top and the middle of the outer wall can be reduced when the wood beam is used as the support between the inner wall and the outer wall.

Distribution and secondary enrichment of heavy metal elements in karstic soils with high geochemical background in Guangxi, China

Karst environments are globally significant, and the soils that develop on these landscapes often have unique geochemical features, including elevated–levels of metals. However, it has not been determined whether the enrichment of metals in soils is mainly controlled by parent rocks or secondary enrichment during weathering. In this paper, we studied the control of the accumulation of heavy metals in soils by parent materials and/or the process of soil formation. We examined the un–weathered carbonate and clastic bedrocks, as well as surface soils in a typical karst area in Guangxi of China. The spatial distribution of heavy metal (Cd, As, Cr, Cu, Hg, Ni, Pb, and Zn) concentrations in soils was mainly controlled by the geological background. Except for Cd, the concentrations of heavy metals in carbonate rocks were much lower than those in clastic rocks, whereas the soils derived from the carbonate rocks were highly enriched with heavy metals than those in clastic area. The enrichment of Cd in surface soils from the carbonate substrates was the result of the dual effect of secondary enrichment and parent rock inheritance, whereas the enrichment of other metals was mainly the result of secondary enrichment. During the weathering process of carbonate bedrock, great majority of the quantities of inherent heavy metals were leached, with only 2% of Cd being retained in situ. The high concentrations of soil Fe, Al, and Mn oxides, organic carbon and clay content (Al2O3/SiO2) were closely related to the enrichment of heavy metals in studied surface soils.

Research on correlation analysis and prediction model of agricultural climate factors based on machine learning

This article uses machine learning technology to analyze the correlation of climate factors that affect crop yields, and conduct prediction and comprehensive evaluation to guide agricultural production. This paper selects early rice crops in Guangxi as the research object. Based on the climatic data of early rice planting areas in Guangxi from 1990 to 2017, a cart decision tree is constructed to generate a random forest model to analyze the correlation between early rice yield and climatic factors in each growth period, and obtain the various growth periods The ranking of the importance of climatic factors on the yield, thus forming the basis for calculating the weights of the climatic factors in each growth period of early rice; based on the climatic data in Guilin, Guangxi from 2008 to April to July 2017, predicted by the long and short-term memory network Guilin's various climate data from April to July 2018.

Registration of ‘YT 09‐13’ sugarcane

Abstract‘Yuetang 09‐13’ (‘YT 09‐13’) (Reg. no. CV‐197, PI 695070) sugarcane (a complex hybrid of Saccharum spp.) was selected and evaluated by the researchers of Institute of Bioengineering, Guangdong Academy of Sciences, from the progenies of a cross between YT 93‐159 (female) and ROC 22 (male). It was released to the growers in Guangdong Province, China, in July 2017. Yield data from three crop cycles (plant cane, first ratoon, and second ratoon) of 15 regional trials during 2015–2017 showed that the average cane yield of YT 09‐13 was 100.66 Mg ha−1, about 3.41% higher than that of ROC 22 (the check cultivar); the average sugar yield was 14.88 Mg ha−1, about 6.82% higher than that of ROC 22 (the check cultivar); and the average fiber content was 10.41%. YT 09‐13 is tolerant to drought and resistant to smut, Sugarcane mosaic virus, and brown rust diseases. YT 09‐13 is a suitable cultivar for planting and distributing in the main sugarcane areas of Hainan, Guangdong, Guangxi, and Yunnan.

基于MaxEnt优化模型的闽楠潜在适宜分布预测

闽楠是我国二级保护珍稀濒危植物，不仅是珍贵用材树种，还具有重要的生态价值，预测其潜在适生区变化具有重要意义。采用Enmeval优化包调用MaxEnt模型建立最优模型。基于186条分布记录和9个环境变量模拟闽楠现代2050和2090年代的6个气候情景潜在分布区。综合Jackknife检验、置换重要值和贡献率、多元相似度面和最不相似变量，探讨影响闽楠适生分布区的环境因子，并分析空间变换格局。结果表明：（1）最优模型的参数为：FC=PT，RM=0.5，Maxnnt模型的预测准确度极高，AUC=0.9846±0.0037，现代闽楠潜在适生区的面积为54.32×10⁴km²，闽楠现代高度适生区集中分布在湖南南部和广西东北部；（2）在未来6种气候变化情景下，闽楠潜在适生分布区均有向北扩张的趋势，除2050s-SSP585外，其余情景适生区面积均增加较小，特别是情景2090s-SSP126下，高度适生区将减少40.32%；（3）最干月降水量（bio14）、降水季节性变化（bio15）、最冷月最低温（bio6）、最暖季降水量（bio18）和最暖月最高气温（bio5）是制约闽楠分布格局的主要环境因子；（4）闽楠各个时期的地理分布范围差别较大，说明闽楠对气候变化抗逆性较差，滥砍滥伐、生境破坏和自身繁育问题可能是致濒的重要原因，福建、江西、湖南和广西东北部是闽楠的稳定适生区和未来气候避难区，台湾中部、福建、江西、湖南、湖北西南部和浙南为理想的闽楠人工林引种区，随着气候变暖的日益加剧，粤桂黔三省（区）丧失区面积比较大，并建议对粤桂黔群体进行优先保护。;Phoebe bournei is a rare and endangered plant under second-class protected plant in China. It is not only a valuable timber tree species, but also has important ecological value. It is of great significance to predict the changes of its potential suitable areas. In order to establish the optimal model, we use the maximum entropy (MaxEnt) optimized by the Enmeval data packet. Based on 186 distribution records and 9 environmental variables, the potential distribution areas of six climatic scenarios in 2050s (average of 2041-2060) and 2090s (average of 2081-2100) were simulated. Integrating Jackknife test, important value and contribution rate of replacement and the limited environmental factors, the environmental factors affecting the suitable distribution area of P. bournei were discussed. The results show that (1) the parameters of the optimal model are FC=PT, RM=0.5, Maxnnt model has high prediction accuracy, the area under the receiver operating characteristic curve (AUC) of 0.9846±0.0037. The total suitable area of the modern potentially geographical distribution of P. bournei 54.32×10⁴km². The modern highly suitable areas of P. bournei are concentrated in northeast Guangxi and southern Hunan. (2) In the prediction of the future suitable growth areas, the potential suitable growth areas under the six climate scenarios all expanded northward, with the exception of 2050s-SSP585; the other scenario suitable areas increased slightly, especially under the scenario 2070s-SSP126, the highly suitable areas will be reduced by 40.32%. (3) The precipitation of the driest month (bio14), precipitation seasonality (coefficient of variation) (bio15), minimum temperature of the coldest month (bio6), precipitation of the warmest quarter (bio18), and maximum temperature of the warmest month (bio5) are important environmental factors restricting the distribution pattern of P. bournei. (4) The geographical distribution range of P. bournei in different periods was quite different, which indicated that P. bournei had poor resistance to climate change. Deforestation, habitat destruction and self breeding problems may be the important reasons for its extinction. Fujian, Jiangxi, Hunan and southern Zhejiang are stably suitable areas and future climate refuge areas for P. bournei. The central Taiwan, Fujian, Jiangxi, Hunan, southwest Hubei, and southern Zhejiang are ideal introduction areas of P. bournei plantation. With the aggravation of climate warming, most areas of Guangdong, Guangxi and Guizhou will no longer be suitable for the growth of P. bournei, and it is suggested that priority should be given to the protection of the population in Guangdong, Guangxi and Guizhou.

基于“三生空间”的土地利用功能演变及生态环境响应——以桂西资源富集区为例

分析土地利用功能演变及生态环境响应是区域'三生空间'划定和管控以及生态环境保护的重要依据。以桂西资源富集区为例，基于1995年、2000年、2005年、2010年和2015年5期遥感数据，构建'三生空间'土地利用主导功能分类体系，运用转移矩阵、重心转移和生态环境响应模型分析研究区20年土地利用功能演变特征及生态环境响应情况，结果表明：（1）研究区生态生产空间和生活生产空间面积呈上升趋势，生产生态空间和生态空间面积呈下降趋势。（2）生态生产空间重心转移距离最大，其次是生活生产空间重心，生产生态空间和生态空间重心转移距离较小。（3）研究区生态环境质量指数从1995年的0.6337持续降至2015年的0.6323，整体质量有所下降。（4）以林草地为主要地类的县域生态环境质量较高，重点矿产资源型县域和农产品生产基地生态环境质量较低，城镇化重点县域生态环境质量最低。

Comprehensive evaluation of low temperature and waterlogging stress of direct-seeding rice at bud stage and seedling stage using membership function method

[Objective] Under the double stress of low temperature and waterlogging stress, some rice varieties area were evaluated, evaluation of the ability of early rice varieties to withstand low temperature and waterlogging stress during bud stage and seedling stage in double cropping rice area of Guangxi was conducted, and screened out the rice varieties suitable for early rice direct seeding, so as to provide reference for suitable early rice varieties of direct seeding in Guangxi. [Method] Based on the artificial simulated low temperature environment, the germination seeds of 25 tested rice varieties were treated with low temperature and waterlogging [daily average temperature 5 °C (12 h light +12 h darkness), water depth of germination box was 5 cm] and control [daily average temperature 5 °C (12 h light+12 h darkness), water depth of germination box was 3 mm]. The seeds of tested varieties after accelerating germination were cultured for 10 d. After this treatment, the seeds were restored to 28 T and continued to grow for 10 d. The seedling rate, root length, root numbers, seedling height, fresh weight per plant, above-ground fresh weight and root fresh weight were measured, and their low temperature and waterlogging tolerance abilities were comprehensively evaluated by membership function analysis and correlation analysis. [Result] Seedling rate stress coefficient of 25 rice varieties was different, the variation was 0-1.00, the average stress coefficient was 0.935. Through the correlation analysis of stress coefficient, there was significant positive correlation between seedling rate and above-ground fresh weight per plant under stress ( P<0.05, the same below), and positive correlation with other traits, but the correlation did not reach significant level ( P>0.05, the same below). Seedling height was extremely positively correlated with root length, above-ground fresh weight and root fresh weight ( P< 0.01, the same below), and significantly positively correlated with root number and plant fresh weight. According to the average results of membership function, the tested varieties were divided into three types: strong, medium and weak tolerance. There were nine varieties with strong tolerance, they were: Guiyu 12, Wushansimiao, High quality farm seed 2, Guiyu 9, Jinsimiao, Xiangzhou fragrant rice, Hexifengzhan, Y liangyou 1, Guiyu 11. Compared with the medium tolerancetypes and weak tolerance types, the rice varieties with strong tolerance hadimprovement in root length, root number, root fresh weight and seedling height. Compared with the control, under the condition of low temperature and waterlogging stress (LT+W), all measurements of plant traits were decreased, and the root length decreased the most, reaching 19.0%, followed by root fresh weight and root number, which decreased by 18.2% and 16.3% respectively. [Conclusion] The key indexes of tolerance to low temperature and waterlogging stress of direct seeding early rice are seedling rate, root indexes (root length, root number and root fresh weight) and seedling height. Nine varieties such as Guiyu 12 can be directly used in the production of direct seeding rice in Guangxi, and can also provide materials for the study of the mechanism of rice tolerance to low temperature and waterlogging and the cultivation of suitable direct seeding rice varieties. 摘要: 【目的】 对广西双季稻区早稻品种芽期和幼苗期耐低温淹水能力进行评价, 为广西稻区直播早稻品种选择 供参考。 【方法】 以25个水稻品种为试验材料, 基于人工模拟低温环境, 设低温淹水[日均温5 °C:(12 h光照+ 12 h黑 暗), 发芽盒水层深度5 cm]和对照[日均温5 °C:(12 h光照+12 h黑暗), 发芽盒水层深度3 mm]2个处理, 对供试品种已 催芽的种子培养处理10 d,处理结束后, 恢复到28 t条件下继续培养10 d,使种子恢复生长。测定成苗率、根长、根 数、苗高、单株鲜重、地上部鲜重和根鲜重, 通过隶属函数值分析和相关分析, 对其耐低温淹水能力进行综合评价和筛 选。 【结果】 25个水稻品种的成苗率胁迫系数存在明显差异, 变幅为0~1.00,平均胁迫系数为0.935。各指标胁迫系数 的相关分析结果表明, 成苗率与单株地上部鲜重呈显著正相关( P<0.05, 下同), 与其他性状也呈正相关, 但相关性未 达显著水平( P>0.05)。苗高与根长、地上部分鲜重和根鲜重呈极显著正相关( P<0.01), 与根数和株鲜重呈显著正相 关。根据隶属函数值将供试品种的耐低温淹水胁迫能力分为强、中、弱3种类型, 其中耐性强的品种有9个, 分别为桂 育12号、五山丝苗、优质农家种2号、桂育9号、金丝苗、象州香米、河西丰占、Y两优1号和桂育11号; 与耐性弱和耐性中 的水稻品种比较, 耐性强的水稻品种在根长、根数、根鲜重和苗高上有明显优势。与对照相比, 低温淹水胁迫下, 幼苗 的根长、根数、苗高、单株鲜重、地上部鲜重和根鲜重均有所降低, 其中根长降幅最大, 达19.0%, 其次是根鲜重和根 数, 降幅分别为18.2%和16.3%。 【结论】 成苗率、根系指标(根长、根数和根鲜重)和苗高可作为直播早稻耐低温淹水逆 境胁迫的关键筛选指标。桂育12号等9个品种可直接用于广西直播稻生产上, 也可为水稻耐低温淹水机理研究及培 育适合机直播的水稻品种提供材料。

Soil Threshold Values for Zn Based on Soil-Rice System and Health Risk Assessment in a Typical Carbonate Area of Guangxi.

Zinc (Zn) is enriched in carbonate area related to geological genesis. To ensure safety of rice, soil threshold values of Zn in soil-rice systems were assessed based on analysis of soil-rice Zn concentration in relation to human health risk. Models for the prediction of Zn concentration of early-season and late-season rice grain were accurately established on the basis of significant partial correlations between log10 (BAFs) and log10 (soil properties). The rice threshold value ranged from 10.67 to 37.90 mg/kg, which might not suitable for male and urban residents. The soil safety threshold of early-season rice and late-season rice in carbonate area ranged from 148-200 mg/kg, 119-200 mg/kg with pH below 6.5, 148-250 mg/kg, 119-250 mg/kg with pH ranging from 6.5 to 7.5; 148-300 mg/kg, 119-300 mg/kg with pH above 7.5, respectively.

不同入侵程度下飞机草对喀斯特地区土壤理化性质的影响

外来生物入侵威胁着全球的生物多样性和生态系统的功能，研究外来入侵植物对土壤理化性质的影响有助于理解外来入侵植物的入侵机制。以广西喀斯特地区飞机草（Chromolaena odorata）入侵生境为研究对象，比较分析了不同飞机草入侵程度下（对照、轻度入侵、中度入侵、重度入侵）土壤物理和化学指标变化特征。结果表明：随着飞机草的入侵程度加重，土壤容重显著增加，轻度入侵、中度入侵和重度入侵生境下土壤容重分别比对照增加了10.3%、16.7%、22.3%，土壤非毛管孔隙度、总孔隙度和土壤含水量显著降低，土壤毛管孔隙度无显著变化；飞机草入侵对土壤pH值无显著影响，随着入侵程度加重，土壤速效磷和速效钾的含量显著升高，在重度入侵生境下土壤速效磷和速效钾含量分别比对照增加了4.3倍、3.8倍，土壤全氮和有机质含量显著降低。飞机草入侵显著改变了土壤理化性状，导致喀斯特地区土壤物理结构退化，生态系统水土保持能力下降，同时飞机草通过改变土壤养分循环提高了土壤可直接利用养分的水平，创造对自身有利的土壤环境，进而促进其生长和扩散。;Invasion of alien species threatens the global biodiversity and ecosystem functions. Studying the effects of alien invasive plants on soil physical and chemical properties is helpful to understand the invasion mechanism of alien plants. In this study, the characteristics of soil physical and chemical indexes under different invasion degrees (control, mild invasion, moderate invasion, and heavy invasion) of Chromolaena odorata in karst area of Guangxi were compared and analyzed. The results showed that soil bulk density increased significantly with the invasion of C. odorata. Compared with the control, the soil bulk density increased by 10.3%, 16.7% and 22.3% respectively in light invasion, moderate invasion and heavy invasion habitats, while soil non capillary porosity, total porosity and soil water content decreased significantly, and soil capillary porosity had no significant change. C. odorata invasion had no significant effect onsoil pH value. The contents of soil available P and K increased significantly with the increase of invasion degree. Compared with the control, the contents of soil available P and K increased by 4.3 times and 3.8 times in heavy invasion habitat, respectively. The contents of soil total N and organic matter decreased significantly. The invasion of C. odorata significantly changed the soil physical and chemical properties, resulting in the degradation of soil physical structure and the decline of soil and water conservation capacity of ecosystem in karst area. Meanwhile, the invasion of C. odorata improved the level of soil available nutrients by changing the soil nutrient cycle, created favorable soil environment for itself, and then promoted its growth and spread.

Study of the genotypic and hematological feature of hemoglobin H disease in West Guangxi area

To analyze the incidence, genotype and hematological feature of hemoglobin H (HbH) disease in West Guangxi region. A total of 1246 patients diagnosed with HbH disease from January 2013 to December 2018 in our hospital were enrolled. Red blood cell parameters, hemoglobin electrophoresis, Gap-polymerase china reaction (Gap-PCR) and polymerase chain reaction-reverse dot blot (PCR-RDB) techniques were used to detect the 6 common α-thalassemia mutations and 17 common β-thalassemia mutations. The results were compared with those of other regions. The detection rate for HbH disease was 5.66%. Among the 1246 patients, 614 (49.28%) had deletion-type HbH disease, including -α 3.7/--SEA (35.32%),-α 4.2/--SEA(13.72%) and -a 3.7/--THAI(0.24%), 632(50.72%) had non-deleted HbH disease, mainly α CS α /--SEA (44.86%), followed by α WS α/--SEA (4.33%), α QS α /--SEA (1.45%) and α CS α/--THAI(0.08%). Co-committent HbH disease and β-thalassemia were detected in 54 cases (4.33%). Most patients with HbH disease showed mild to moderate anemia. Very few had severe anemia. Among these, patients with HbH-CS had the most severe anemia, and HbH-WS were the mildest. Hb levels in patients with HbH disease alone were lower than those with co-committent HbH and β-thalassemia. Compared with other regions, the incidence and genotype of HbH disease of West Guangxi are different. The prevalence of HbH disease is high in West Guangxi region, and the main genotypeis non-deletion. α CS α /--SEA is the most common, and most of them had moderate anemia. Compared with the deletion-type HbH disease, non-deleted HbH patients were more severe. When HbH disease co-committed with β-thalassemia, the severity of anemia is reduced. The difference between West Guangxi and other regions may account for the variance of clinical manifestations and incidence of HbH disease in this region.

Influence of complex topography on magnetotelluric-observed data using three-dimensional numerical simulation: A case from Guangxi area, China

Influence of complex topography on magnetotelluric-observed data using three-dimensional numerical simulation: A case from Guangxi area, China

Spatial distribution of preferential flow paths in paddy field in the Karst Area of Guangxi.

The spatial distribution of the preferential flow path in soil affects the occurrence and movement of preferential flow. In afield soil staining and tracing experiment, with the help of morphological image analysis technology and community ecological analysis method, we examined the spatial distribution characteristics of preferential flow path in paddy fields under straw mulching (CM) and non-mulching (CK) in karst areas of Guangxi. The results showed that, under the same external water supply conditions, with the increases of soil depth, soil horizontal dyeing changed from overall distribution to clump aggregation distribution in paddy field under straw mulching. In the non-mulching paddy field, the main dyeing was branch, with an average shape coefficient of staining patch of 21.69. The dyeing morphology in the non-mulching paddy field was 1.04 times of straw mulching paddy field. The preferential flow paths of straw mulching and non-mulching paddy fields showed both clustered distribution. In straw mulching paddy field, the Morisita index was 1.28 as the preferential flow paths with radius of influence less than 1.0 mm were the main ones (importance value 0.31). The importance value of preferential flow paths with radius less than 1.0 mm was 0.28 in non-straw mulched rice field. Straw mulching affected the preferential flow paths in paddy fields, which could help to improve water and fertilizer utilization of crops in the field.

Genetic Diversity of Phyllanthus emblica From Two Different Climate Type Areas.

Phyllanthus emblica L. is a well-known medicinal and edible plant species. Various medicinal compounds in the fruit make it an important medicinal and promising economic material. The plant is widely distributed in Southwestern and Southern China. However, due to massive deforestation and land reclamation as well as deterioration of its natural habitat in recent years, the wild resources of this species have been sharply reduced, and it is rare to see large-scale wild P. emblica forests so far. In order to effectively protect and rationally utilize this species, we investigated the genetic diversity, genetic structure, and population dynamics of 260 individuals from 10 populations of P. emblica sampled from the dry climate area in Yunnan and wet climate area in Guangxi using 20 polymorphic EST-SSR markers. We found high genetic diversity at the species level (He = 0.796) and within populations (He = 0.792), but low genetic differentiation among populations (FST = 0.084). In addition, most genetic variation existed within populations (92.44%) compared with variation among the populations (7.56%). Meanwhile, the NJ tree, STRUCTURE, and hierarchical analysis suggested that the sampled individuals were clustered into two distinct genetic groups. In contrast, the genetic diversity of the dry climate group (He = 0.786, Na = 11.790, I = 1.962) was higher than that of the wet climate group (He = 0.673, Na = 9.060, I = 1.555), which might be attributed to the combined effects of altitude, precipitation, and geographic distance. Interestingly, only altitude and precipitation had significant pure effects on the genetic diversity, and the former was slightly stronger. In addition, DIYABC analysis suggested the effective population size of P. emblica might have contracted in the beginning of the Last Glacial Maximum. These genetic features provided vital information for the conservation and sustainable development of genetic resources of P. emblica, and they also provided new insights and guidelines for ecological restoration and economic development in dry-hot valleys of Yunnan and karst areas in Guangxi.