Chinese Journal of Tropical Crops
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    25 November 2019, Volume 40 Issue 11 Previous Issue    Next Issue
    Crop Culture and Nutrition, Genetic Breeding
    Effects of Water-retention Treatment on the Physiological Characteristics and Latex Yield of Hevea brasiliensis
    YUAN Huifang,HUANG Jing,YUE Hai,TIAN Yaohua
    2019, 40 (11):  2097-2104.  doi: 10.3969/j.issn.1000-2561.2019.11.001
    Abstract ( 580 )   HTML ( 15 )   PDF (598KB) ( 400 )  

    Rubber tree variety ‘Yunyan 77-4’ was selected as the test material. With conventional management (without covering) as the control, covering film, covering grass and adding water-retaining agent were adopted as the three water-retaining treatments. Through field comparative experiments, the effects of different treatments on the physiological characteristics of leaves and latex yield at different growth stages of rubber tree in the whole year were studied. The results of variance analysis showed that covering film, covering grass and adding water retaining agent significantly increased soil water content in dry season, and significantly affected the contents of soluble protein (SP), proline (Pro), soluble sugar (SS) and sucrose (Suc) in the leaves of rubber trees. The yield of latex increased by the three water retaining treatments. Principal component analysis showed that the cumulative contribution rate of the first three principal components was 84.8%, indicating that the first three principal components could reflect most of the information of original variables. According to the comprehensive score, the order of the advantages and disadvantages of each treatment was as follows: adding water-retaining agent, covering grass, covering film and the control. The order of comprehensive performance of physiological indexes of rubber leaves at different growth stages in the whole year was as follows: December, March, January-February, November, June, July, September-October, August, May and April. Therefore, it can be inferred from the results that all water conservation treatments can effectively alleviate the adverse effects of seasonal drought on the growth of rubber trees. In terms of production, a reasonable tapping period can be selected according to the comprehensive performance of physiological indexes of leaves at different growth stages throughout the year.

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    Effect of Fertilization on Two New Planting Materials of Rubber Seedlings
    BEI Meirong,CAI Jun,QI Chunlin,LIN Qinghuo,LUO Wei,LIU Hailin,CHA Zhengzao
    2019, 40 (11):  2105-2111.  doi: 10.3969/j.issn.1000-2561.2019.11.002
    Abstract ( 521 )   HTML ( 16 )   PDF (496KB) ( 315 )  

    Two new planting materials, including mini-seeding budding seedlings and self-rooting juvenile are planted more and more widely in natural rubber cultivation. However, nutritional characteristics of the two new planting materials are still unclear. In this study, fertilizer test was carried out to study how the two planting materials responding to different fertilizer rates in dry matter accumulation (DMA), and nitrogen, phosphorus and potassium accumulation (NPKA), as well as fertilizer use efficiency (FUE). Results indicated that (1) DMA in self-rooting juvenile was significantly higher (P<0.01) than that in mini-seeding budding seedlings at fertilization level 2, 3, 4, and DMA increased by 32.1%, 66.7%, 32.9%, respectively. (2) NPKA of the two planting materials both increased firstly and then decreased with the increase of fertilizer rate. Also, NPKA of different organs of the two planting materials were both high in stem and low in lateral root except nitrogen accumulation of leaf of mini-seeding budding seedlings. Nitrogen accumulation was the largest, followed by potassium accumulation, and phosphorus accumulation was the least. Overall, NPKA of self-rooting juvenile was higher than mini-seeding budding seedlings. (3) FUE of the two planting materials both decreased with the increase of fertilizer rate. FUE of potassium was the highest, followed by nitrogen, and phosphorus was the lowest.

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    The Growth Difference of Cynodon dactylon Accessions of Different Aluminum Tolerance on Acidity Soil
    HUANG Chunqiong,LIU Guodao,CHEN Zhen
    2019, 40 (11):  2112-2118.  doi: 10.3969/j.issn.1000-2561.2019.11.003
    Abstract ( 466 )   HTML ( 17 )   PDF (425KB) ( 359 )  

    Five Al-tolerance and five Al-sensitive Cynodon dactylon (L) Pers. accessions respectively selected based on the preliminary study were planted in acidity soil. The growth index of the leaf color, turf high, number of tiller, and turf quality were assessed after growing in acidity soil for 28 days in order to study the growth difference of C. dactylon accessions. The results showed that Al-tolerance and Al-sensitive C. dactylon accessions were significantly different except turf height. The growth of Al-tolerance accessions was less inhibited than the Al-sensitive accessions. Al-tolerance accessions could maintain high growth rate in acidity soil. The results of the study would provide reliable materials for the follow-up study on the mechanism of aluminum resistance and the breeding of aluminum resistant varieties of C. dactylon.

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    Environment Impact Assessment of Pitaya Production System with LCA Method in Guangxi
    ZHAO Pengfei,CHENG Yu,REN Taijun,HUANG Zhijian,LI Guangze,TANG Hua,RUAN Yunze
    2019, 40 (11):  2119-2126.  doi: 10.3969/j.issn.1000-2561.2019.11.004
    Abstract ( 504 )   HTML ( 17 )   PDF (824KB) ( 353 )  

    To evaluate the environmental impact of pitaya production and find out the main impact factors, a baseline household survey in Guangxi was conducted meanwhile the method of Life Cycle Assessment (LCA) was used for data analysis. Among all potential impacts indexes, the significant environmental impact were eutrophication and global warming potential, with the contribution rate of 59.6% and 21.7%, respectively. Fertilizer production and application accounted for 98.0% and 99.8% of the eutrophication in agricultural production stage and agricultural operation stage, correspondingly. In the global warming aspect, fertilizer and pesticide production accounted for 20.0% and 77.9% in agricultural production stage, which made the largest contribution among all the links. Similarly, fertilizer application, which accounted for 86.6% of the global warming potential, made the largest contribution in agricultural operation stage. To sum up, reducing fertilizer and pesticide application rate are the important ways to mitigate the impact on the environment in pitaya production.

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    Technological Quality Evolution Analysis and Screening of Sugarcane Germplasm Introduced From the United States
    ZHAO Yong,ZHAO Liping,ZAN Fenggang,ZHU Jianrong,QIN Wei,ZHAO Jun,ZHAO Peifang,LIU Jiayong
    2019, 40 (11):  2127-2134.  doi: 10.3969/j.issn.1000-2561.2019.11.005
    Abstract ( 573 )   HTML ( 19 )   PDF (924KB) ( 309 )  

    The generational evolution and germplasm evaluation of major technological quality traits in the sugarcane germplasms introduced from the United States were analyzed based on the Projection Pursuit Classification (PPC). Fifty-eight American sugarcane germplasms were divided into four improved generations according to the breeding or improvement years (10-20 years as the time boundary). Based on field experiments, variance, projection pursuit classification and cluster analysis were carried out on five important technological quality traits such as brix, sucrose content, sugarcane juice sugar content, sugarcane fiber content and sugarcane purity to reveal the generational evolution characteristics and screen excellent germplasms for cross breeding. Variance analysis showed that there were significant differences in technological quality traits between generations and in generations (P<0.05), and the coefficient of variation was between 2% and 20%. There were significant interactions among generations and months among sugarcane sugar, sucrose content in juice and purity. PPC analysis showed that the projection values of sugarcane germplasms in different generations of the United States were significantly different, among which the first generation was the lowest, increased in turn, and the fourth generation was the highest; the projection direction was the highest sucrose content in sugarcane, followed by sucrose content in sugarcane juice and brix content in sugarcane, with the lowest purity and fiber content. Cluster analysis based on projection values showed that the germplasms could be divided into four groups. Eighteen sugarcane germplasms (group II) with good technological quality traits were screened for cross breeding. Six of them came from the fourth generation, accounting for 46.15% of the total number of materials in the fourth generation; ten from the third generation, accounting for 37.07% of the total number; one from the second generation, accounting for 18.18% of the total number; and no good quality germplasm resources were screened from the first generation. The above results showed that the main technological quality of sugarcane germplasm resources in the United States had been significantly improved, and had been significantly improved with the evolution of generations. Projection pursuit taxonomy could be used as another way to evaluate the improvement effect and germplasm resources of sugarcane.

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    Phytophysiology and Biochemistry
    Preliminary Evaluation on Cold Resistance of Cacao Germplasm Resources and Physiological Response under Low Temperature Stress
    LI Fupeng,WU Baoduo,QIN Xiaowei,YAN Lin,LAI Jianxiong
    2019, 40 (11):  2135-2141.  doi: 10.3969/j.issn.1000-2561.2019.11.006
    Abstract ( 518 )   HTML ( 18 )   PDF (4317KB) ( 356 )  

    During the extreme low temperature period of January 2016, cold resistance of 38 cacao germplasms were evaluated in Wanning, Hainan. According to the damage degree of cacao pods and leaves after low temperature, five grades were distinguished among the cacao germplasms. Using the selected cold resistance difference germplasms INA-t5 (grade Ⅰ), COM-e8 (grade Ⅱ), ECU-ev6 (grade Ⅳ) and THA-o6 (grade V), leaves anatomy and physiological responses of the cacao plants were studied after 4 ℃ low temperature treatment. Under low temperature stress, INA-t5 and COM-e8 showed obvious cold-tolerance over THA-o6 and ECU-ev6, and the damage degree of the leaves was significant. It was negatively correlated between cold resistance and malondialdehyde, proline content in cacao leaves. The protective enzyme systems of THA-o6 and ECU-ev6 were gradually destroyed in low temperature stress for 48 h, while the enzyme system of INA-t5 and COM-e8 were still active. It meant that the cold resistance of INA-t5 and COM-e8 was stronger than that of THA-o6 and ECU-ev6. The antioxidant enzyme activity, osmotic substances content and cold-resistance difference germplasm could be used for cold-resistant breeding and molecular mechanism investigation.

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    The Change Characteristics of Endogenous Hormone and Quality Content of Sugarcane under Different Nitrogen Fertilization
    ZHOU Huiwen,CHEN Rongfa,FAN Yegeng,QIU Lihang,LI Yangrui,WU Jianming,HUANG Xing
    2019, 40 (11):  2142-2148.  doi: 10.3969/j.issn.1000-2561.2019.11.007
    Abstract ( 560 )   HTML ( 15 )   PDF (445KB) ( 461 )  

    The sugarcane variety GT42 is a home-bred variety which is the most widely planted in China. It’s necessary to explore the nitrogen demand of the variety to provide references for the scientific management of the variety in the planting areas. Different nitrogenous levels (CK: 0 kg/hm 2, low level: carbamide 150 kg/hm 2, 300 kg/hm 2, middle level: carbamide 450 kg/hm 2, high level: carbamide: 600 kg/hm 2, 750 kg/hm 2) were applied to the variety before the tiller stage, and the content of endogenous hormone (GA, CTK, BR and ABA), final yield and sugar content were measured under different nitrogen fertilization level in the tillering stage. The yield under different levels nitrogenous fertilizer from more to less was 150 kg/hm 2, 300 kg/hm 2, 0 kg/hm 2, 450 kg/hm 2, 600 kg/hm 2, 750 kg/hm 2, and the yield at 150 kg/hm 2 and 300 kg/hm 2 fertilizer level was 5.40% and 2.54% more than the CK, respectively (P<0.01). And the highest yield was in the 150 kg/hm 2 of nitrogen fertilization treatment. The sugar content per hectare was in the same order as the yield, but the nitrogen fertilization levels had no effect on sucrose content. The economic benefit in the order from more to less 150 kg/hm 2, 0 kg/hm 2, 300 kg/hm 2, 450 kg/hm 2, 600 kg/hm 2, 750 kg/hm 2. The variation tendency of the content of GA and BR were the same that reached the maximum at 150 kg/hm 2 of nitrogen fertilization level and then decreased with the increase of nitrogen fertilization level. The content of ABA was the opposite, increasing with the increase of nitrogen fertilization level. The content of CTK increased first, decreased then and increased finally.

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    Effects of Rhizosphere Soil Chemicals on Growth and Quality of Tea Trees at Different Ages
    WANG Haibin,CHEN Xiaoting,WANG Yuhua,ZHAO Hu,ZHANG Huabin,DING Li,KONG Xianghai,YE Jianghua
    2019, 40 (11):  2149-2159.  doi: 10.3969/j.issn.1000-2561.2019.11.008
    Abstract ( 658 )   HTML ( 15 )   PDF (1349KB) ( 351 )  

    In order to analyze the effect of tea tree rhizosphere soil chemicals on the growth and quality of tea tree, the rhizosphere soils from Tieguanyin tea plantations of 0, 3, 9 and 25 years old were extracted and eluted through different polar resins to discuss the effects of rhizosphere soil with different planting ages on the growth and quality of tea trees. The inhibitory effects by resin eluents on the receptor dry weight were in the order, 25>9>3>0 years, furthermore, the ADS-7 resin adsorption eluent had the strongest inhibitory effect. After exogenous addition the different resin eluent, the contents of IAA and ZR in the tea leaves significantly decreased with the increase of tea tree age, when treated by the same resin eluent, while the ABA content showed a significant increase. In addition, when the tea trees were in the same age, and the effect of different resins were still the ADS-7 most, as showed that the contents of IAA and ZR in the tea leaves were the lowest and the ABA was the highest. Analysis of the contents of amino acids in the tea leaves showed that the contents of total amino acids, hydrophilic amino acids, sweet amino acids and umami amino acids in the tea leaves were showed a downward trend with the increase of tea tree age after treated by different resin eluent. In summary, the rhizosphere soil chemicals of tea tree had an autotoxicity effect on tea tree and the ADS-7 resin eluents from 25-year-old tea tree rhizosphere soil were the stronges.

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    Life Table and Survival Analysis of Heritiera littoralis Population in Baguang, Shenzhen
    SUN Hongbin,XIAO Shihong,CAI Jian,GAO Changjun,YI Xiaoqing,WU Yan,WEI Long,WANG Zuolin
    2019, 40 (11):  2160-2165.  doi: 10.3969/j.issn.1000-2561.2019.11.009
    Abstract ( 531 )   HTML ( 15 )   PDF (506KB) ( 400 )  

    The specific life table of Heritiera littoralis population in Baguang, Shenzhen was compiled based on the population life table and the survival analysis using the DBH (diameter at breast height) class method and smoothing out technique. The mortality rate curve, vanishing rate curve, survival rate curve and survival function curve were calculated, and the population dynamics were also analyzed. In H. littoralis population, the seedlings and young trees were in larger quantity, while the aged ones were fewer, indicating that the population was overall a growing population. The population was stable even taking potential future disturbance into account. The survival curve was more of Deevey-Ⅲ type. The mortality and vanishing curves both exhibited the same trend, existing two peaks in the lifespan. One was in the 1 st age and the other was in the 3 rd. Analysis of four survival functions of H. littoralis population showed that the survival function curve increased all long, while the cumulative mortality function curve decreased all the time. The increasing or decreasing range was higher at young stage than that at middle or mature stages. The death density function curve was relatively stable. The hazard rate function curve was increasing from the 3 rd age to the 12 th age, with the growth of age class. The death density and hazard rate function curves were highest during the 2 nd age class.

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    Biotechnology and Tissue Culture
    Screening of Suitable Reference Genes for qRT-PCR Normalization in Sisal
    ZHANG Yanmei,WANG Ruifang,YANG Ziping,LU Zhiwei,LI Junfeng,ZHAO Yanlong,LU Junying,ZHOU Wenzhao
    2019, 40 (11):  2166-2173.  doi: 10.3969/j.issn.1000-2561.2019.11.010
    Abstract ( 545 )   HTML ( 16 )   PDF (1909KB) ( 575 )  

    In this study, eight reference genes (EF1α, MADH, ACT2, GAPDH, TUB, ACT54, CYP and EF1β) from the transcriptome database, were selected and analyzed in Rema No.1 including Phytophthora nicotianae Breda, MeJA, SA and ABA treatments. Statistical tools, including GeNorm, NormFinder and BestKeeper, were utilized to assess the suitability of reference genes based on the stability rankings for different species. The stability of the eight reference genes was significantly different under different treatments in Rema No.1. For Phytophthora nicotianae Breda and MeJA stresses, EF1α was identified as the most stable gene and EF1β was identified as the least stable gene. For SA stress, EF1α was identified as the most stable gene, and ACT2 was identified as the least stable gene. For ABA stress, GAPDH was identified as the most stable gene, and ACT54 was identified as the least stable gene. The results would provide reliable and optional available reference genes in gene expression analysis of sisal.

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    Tissue Culture and Rapid Propagation Technology of Hopson Flower of Musa velutina
    HUANG Dongmei,XU Yi,LI Jingyang,LI Yujia,LIN Fei,LI Yanxia,SONG Shun
    2019, 40 (11):  2174-2177.  doi: 10.3969/j.issn.1000-2561.2019.11.011
    Abstract ( 560 )   HTML ( 14 )   PDF (1476KB) ( 373 )  

    As a wild banana resource, Musa velutina can be regarded as an important genetic and breeding resource and has an ornamental value. In this study, the tissue culture and rapid propagation technology of Musa velutina were studied using the hopson flowers as the plant materials. Callus could be induced by the callus induction medium. The best bud differentiation medium was MS+6-BA (3.0 mg/L)+NAA (0.1-0.2 mg/L), the best bud proliferation medium was MS+6-BA (2.0 mg/L)+NAA (0.1 mg/L), and the best rooting medium was MS+IBA (3.0 mg/L)+NAA (0.3 mg/L). It took about 100 d from sampling to obtaining tissue culture seedlings with complete root system, and the reproduction efficiency was more than 100 plants/flower bud.

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    Crop Pests, Diseases and Their Control, Environmental Protection
    Occurrence Pattern Investigation and Fungicides Control Effect in Field for Cassava Brown Leaf Spot Disease in China
    SHI Tao,LI Chaoping,CAI Jimiao,WANG Guofen,LU Cuimei,HAN Quanhui,HUANG Guixiu
    2019, 40 (11):  2178-2188.  doi: 10.3969/j.issn.1000-2561.2019.11.012
    Abstract ( 602 )   HTML ( 13 )   PDF (1217KB) ( 311 )  

    Brown leaf spot (BLS) is the common disease on in cassava worldwide, and it is also the important disease in China. Based on the previous study, the investigation and popular characteristic research in China was launched in our lab. The result showed BLS was widely occurred in the main cassava planting areas of China. BLS was seriously happened at partial cassava plantations, and most varieties were sensitive. In three years, the systematic investigation of three cassava varieties in two sites was finished. We found BLS usually occurred in the middle growing stage of cassava, increasing as the disease progressed, then popular and damage at mid-later stage. Field test studied illustrated Prochloraz, Carbendazim, Propiconazole had a better control effect for BLS, which was suggested to be used in cassava plantation.

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    Comparison and Analysis of Resistance of Eight Banana Accessions to Fusarium wilt
    HUANG Sumei,WEI Shaolong,WEI Liping,LI Chaosheng,QIN Liuyan,WEI Di,TIAN Dandan,LONG Shengfeng,HE Zhangfei,ZHOU Wei
    2019, 40 (11):  2189-2196.  doi: 10.3969/j.issn.1000-2561.2019.11.013
    Abstract ( 536 )   HTML ( 17 )   PDF (2556KB) ( 416 )  

    The resistant level of eight banana accessions to Fusarium oxysporum f. sp. cubense race 4 (Foc 4) was evaluated using indoor inoculating and planting in disease area. Resistance test at seedling stage revealed GCTCV-119 and GCTCV-217 presented high resistance, Guijiao 9 and GCTCV-218 exhibited resistance, GCTCV-105 and GCTCV-215 showed moderate resistance, but Guijiao 1 and Baxi presented susceptibility and high susceptibility, respectively. Field evaluation indicated that GCTCV-119 and GCTCV-217 also presented high resistance, GCTCV-215 was resistance, and GCTCV-105, Guijiao 9 and GCTCV-218 were of moderate resistance, and both Guijiao1 and Baxi presented high susceptibility. After successive planting in the field for three years, it was found that the morbidity of Guijiao 9 and GCTCV-218 showed a declining trend, but GCTCV-105 kept a stable incidence rate of Fusarium wilt with 9.7%-12.0%. Furthermore, all resistant banana accessions presented resistance grade to Fusarium wilt according to relative incidence rate (RIR) evaluation after ratoon planting for three years, while the incidence rates of Guijiao 1 and Baxi increased year by year, ranged from 98.2% to 100%.

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    Colletotrichum Species Responsible for Leaf Anthracnose of Liquidambar formosana Hance in Fujian
    ZHU Yangyan,SU Jinyu,PAN Aifang,HE Xueyou,HU Hongli
    2019, 40 (11):  2197-2204.  doi: 10.3969/j.issn.1000-2561.2019.11.014
    Abstract ( 814 )   HTML ( 39239 )   PDF (1966KB) ( 920 )  

    Six morphologically different Colletotrichum strains were obtained during the investigation of Liquidambar formosana Hance leaf diseases in Fujian. The six strains were identified based on morphology (colony, acervuli, conidiophores and conidia) and multi-loci (ITS, TUB2, ACT, GAPDH and CHS-1) phylogenetic analyses. The six strains belonged to three Colletotrichum species, i.e., C. fructicola, C. tropicale and C. fioriniae, which belonged to Colletotrichum gloeosporioides complex and Colletotrichum actatum complex, respectively. The results from Koch’s postulates supported the three Colletotrichum species could cause leaf anthracnose to Liquidambar formosana, and the pathogenecity of them was different. This is the first report of the three Colletotrichum species to cause leaf anthracnose on Liquidambar formosana.

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    Agricultural Product Processing, Preservation, Storage, Analysis and Detection
    Processing Properties of Vacuum-assisted-acid Coagulated Natural Rubber
    HE Shuang,LIAO Shuangquan,ZHAO Yanfang,HU Benxiang,LIAO Xiaoxue,ZHAO Fuchun
    2019, 40 (11):  2205-2210.  doi: 10.3969/j.issn.1000-2561.2019.11.015
    Abstract ( 476 )   HTML ( 13 )   PDF (604KB) ( 370 )  

    The performance of natural rubber (NR) is closely related to the processing, and coagulation is an important step in the process. The study used vacuum-assisted-acid to coagulate natural rubber. Compared with naturally coagulated rubber, the effects of vacuum-assisted-acid coagulation on Mooney viscosity, physical and chemical properties, physical and mechanical properties and processing properties of natural rubber were discussed. The physical and chemical properties obtained by different solidification methods had certain differences of NR coagulated by different methods, and the nitrogen content of naturally coagulated NR, vacuum-assisted-acid coagulated NR and acid coagulated NR was in a downtrend. The plastic initial value (P0) and the plastic retention rate (PRI) of the vacuum-assisted-acid solidified NR was higher than that of the natural solidified NR and the acid solidified NR. The PRI of vacuum assisted acid coagulation NR was 85% and the PRI of acid solidification NR was 75.7%. The crosslinking density of vacuum-assisted-acid solidified NR was higher than that of natural solidified NR and acid solidified NR. The tensile strength and elongation at break of vacuum-assisted-acid coagulated NR were higher than that of natural coagulated NR and acid coagulated NR. The tensile strength of the three NRs was 21.06, 19.35 and 17.60 MPa. The RPA test showed that the G' of vacuum-assisted-acid solidified NR, natural solidified NR and acid solidified NR was in a increasing trend, while the tanδ of vacuum-assisted-acid solidified NR, natural solidified NR and acid solidified NR was in a downtrend. The sample obtained by vacuum-assisted-acid solidification had the best processing performance, followed by the natural solidified rubber, and the acid solidified rubber sample was the worst.

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    Dimensional Stability of Compressed Oil Palm Trunk
    LU Quanji,LI Jianing,ZENG Xianhai,JIANG Huichuan,LI Xiaowen,LIU Zhao,LI Min
    2019, 40 (11):  2211-2216.  doi: 10.3969/j.issn.1000-2561.2019.11.016
    Abstract ( 611 )   HTML ( 13 )   PDF (586KB) ( 344 )  

    In order to increase the density of oil palm trunk and improve the dimensional stability, the study presents the effect of initial moisture content and compressed temperature on some properties of compressed oil palm trunk. Oil palm trunk was thermo-mechanically densified in the laboratory scale at 160, 180 and 200 ℃ for the initial moisture content of 20%, 35% and 50%. The results showed that the density of the compressed samples was 0.79-0.88 g/cm 3 at the compression-set of 47.2%-48.8%. The dimensional stability including spring-back, compression-set recovery, water absorption and equilibrium moisture content were improved with increasing hot compressed temperature and initial moisture content. The hot compressed temperature had a more significant effect than that of the initial moisture content.

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    Optimization of Ultrasonic Assisted Extraction of Macadamia Oil and Its Physicochemical Properties
    TU Xinghao,SUN Liqun,TANG Jinghua,ZHANG Ming,SHUAI Xixiang,CHEN Hong,DU Liqing
    2019, 40 (11):  2217-2226.  doi: 10.3969/j.issn.1000-2561.2019.11.017
    Abstract ( 567 )   HTML ( 14 )   PDF (1092KB) ( 546 )  

    In order to improve the extraction rate of macadamia oil and obtain high quality oil, an ultrasonic assisted method was used to extract macadamia oil, and the physicochemical properties of the extracted oil were analyzed. The effects of extraction solvent, ultrasonic power, ultrasonic time and ratio of liquid to material on the extraction rate were investigated by single factor experiments, and then the extraction process parameters were optimized by response surface methodology (RSM). The results showed that the extraction rate of macadamia oil was higher with n-hexane, and the yield of macadamia oil increased with the proper increase of ultrasonic power, ultrasonic time and solvent content. The optimum extraction conditions of macadamia oil were as follows: the ratio of liquid to material 9.6∶1 (mL/g), the ultrasonic power 520 W, the ultrasonic time 32 min, and the yield of macadamia oil was 69.1% under the conditons. The total yield extracted twice reached 96.3%. The results showed that ultrasonic assisted extraction was an effective method for macadamia oil extraction. In terms of fatty acid composition and physicochemical properties, macadamia oil is a kind of natural vegetable oil with high nutritional value.

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    Analysis and Evaluation of Trace Elements in Different Varieties of Loquat Fruits
    YU Xinmiao,CHEN Faxing,LU Haifen,QIU Xiuyu,ZHENG Guohua,YANG Jun
    2019, 40 (11):  2227-2235.  doi: 10.3969/j.issn.1000-2561.2019.11.018
    Abstract ( 560 )   HTML ( 13 )   PDF (6860KB) ( 193 )  

    Nine trace elements in 23 kinds of loquat fruits were determined by inductively coupled plasma mass spectrometry (ICP-MS), and the appearance quality index of the fruit was determined. Principal component analysis, cluster analysis and SPSS 19.0 statistical software were used to comprehensively evaluate the results, and the correlation between fruit quality and trace elements content of different varieties was analyzed too. The order of trace elements content in different varieties of loquat fruits was: Mn>Zn>Fe>Cu>Ni>Co>Mo>Se>V. Mn, Fe and Zn were the mainly trace elements in loquat fruit. Mn, Co, Cu and Se were selected by principal component analysis as the characteristic inorganic trace elements of loquat. The top three varieties were ‘Xinxiao’, ‘Zhuonan No.1’ and ‘Less seeds Dahongpao’ in total ranking. According to the trace element content, the loquat varieties were divided into 3 types. There were 19 varieties in the first type, including ‘Muyuzhong’ and ‘Xiaomaopipa’, which was of high Zn and Fe content. ‘Less seeds Dahongpao’ and ‘Hubei 26’ were in the second type, which was of high Cu content. ‘Zhuonan No.1’ and ‘Xinxiao’ were grouped in the third type, which was of high Mn and Co content. Correlation analysis among trace elements showed that there was an extremely significantly positive correlation between element Mn with Co (|r|=0.852) and Cu (|r|=0.538), and a significant correlation between elements V with Fe and Zn, Co with Cu was seen. As for Ni and Se, they showed a significant correlation. The element Cu showed a highly significant correlation in the transverse diameter of the fruits. At the same time, a correlation analysis between trace elements and fruit quality showed that there was a highly significant correlation between Fe and SSC in the flesh. Based on the results of principal component analysis and cluster analysis, it was concluded that ‘Xinxiao’ had the highest content of trace elements in all 23 loquat varieties. Comprehensive analysis showed the pulp was rich in beneficial trace elements such as Fe, Zn and Mn and other elements. ‘Xinxiao’ was the most nutritious one among the 23 varieties.

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    Effects of Rolling and Rocking Green on the Sensory Quality and Biochemical Components of White Tea
    WANG Feiquan,FENG Hua,ZHU Xiaoyan,LI Shaohua,ZHANG Jianming,ZHANG Bo,DU Hong,CHEN Rongbing
    2019, 40 (11):  2236-2245.  doi: 10.3969/j.issn.1000-2561.2019.11.019
    Abstract ( 555 )   HTML ( 12 )   PDF (1170KB) ( 362 )  

    To develop high fragrance white tea products, the Huangguanyin tea banjhi with three and four leaves were took as test materials. Taking traditional white tea technology as contrast (CK), adding rocking green process (YQ), rolling process (RN), and both two program together (YQ+RN) into the indoor natural withering were took as treatments respectively. The effects of different technology on its the content and composition of aromatic substance, the content of biochemical components and the quality of white tea were compared. The results showed that the fresh leaves of Huangguanyin were with abundant contents and reasonable composition. The aroma components of each treated tea were rich in variety and content: the number of species was between 101-106, and the relative content accounts for 78.10%-84.26% of the total amount of extract. Compared with CK, the treatment group had a significant influence on the total amount and type of principal aroma components of white tea, as well as the composition of aroma components. Among all treatments, the contents of biochemical components of tea was significantly different, the contents of 10 biochemical components including tea polyphenols were the highest in CK, 3 biochemical components including theaflavins were the highest in YQ, 3 biochemical components like flavonoids were the highest in RN, and the contents of theabrownin was the highest in YQ+RN. According to the comprehensive scores of sensory quality, the tea could be sequenced, from high to low, as YQ>YQ+RN>CK>RN, and the differences among the treatments were significant. Through comprehensive analysis, it could be concluded that white tea YQ were with the excellent quality, and the quality characteristics of flower-scented white tea.

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    Feasibility of Processing Black Tea with Fresh Leaves Picked from Famous Tea Bushes in Wuyi Mountains
    LU Li,CHENG Xi,ZENG Jingjing,YE Guosheng,LI Xinghui,CHEN Rongbing
    2019, 40 (11):  2246-2254.  doi: 10.3969/j.issn.1000-2561.2019.11.020
    Abstract ( 477 )   HTML ( 17 )   PDF (1252KB) ( 378 )  

    In order to make full use of the resources of Wuyi Mingcong (famous tea bushes), to enrich the category of black tea, 13 bushes of Wuyi Mingcong were steamed and processed to black tea respectivey, using cultivar ‘Shuixian’ as the control. The suitability for processing black tea of the tested bushes was analyzed based on the biochemical indicators and sensory quality assessments, in which the relationship between the biochemical indicators of fresh leaves and the quality of black tea was analyzed. The results showed that the content of water soluble extracts, amino acids, caffeine, flavonoids in fresh leaves and water soluble extract, tea polyphenols, caffeine, flavonoids, theaflavins, thearubigins in black tea processed from leaves of bush ‘Guidong Baijiguan’ were higher than those in the control, in which the content of theaflavin was 0.81%, being significantly higher than that of the control. The sensory quality of ‘Guidong Baijiguan’ was excellent. Comprehensive biochemical and sensory evaluation results showed that ‘Guidong Baijiguan’, ‘Jinsuoshi’, ‘Jinfenghuang’, ‘Baimaohou’ and ‘Queshe’ were suitable for processing black tea. The ratio of polyphenols to amino acids in fresh leaves was not significantly correlated with the quality of black tea. Water soluble extract, caffeine, the ratio of polyphenols to caffeine, the ratio of amino acids to caffeine in fresh leaves were significantly correlated with the quality of black tea or the factors relating to black tea quality, which could be used as a reference for assessing the suitability for processing black tea of tea cultivar.

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    Optimization of Extraction Process and Detection Method of Dencichine
    DUAN Shaofeng,CHEN Geng,YAN Jing,QIN Zhongming,ZHANG Guanghui,LIANG Yanli
    2019, 40 (11):  2255-2260.  doi: 10.3969/j.issn.1000-2561.2019.11.021
    Abstract ( 485 )   HTML ( 18 )   PDF (631KB) ( 577 )  

    The extraction process of dencichine in Panax notoginseng was optimized by the L9(3 4) orthogonal test, and the content of dencichine was determined by HPLC. The optimized extraction condition for dencichine was extracted once with ultrapure water at solid-to-liquid ratio of 1∶20 (g/mL) for 10 min. Flower bud had the highest dencichine content, followed by rhizome, main roots and leaves. The content of dencichine in flower buds was 3.33%. There was no significant correlation between the content of dencichine and the rhizom size. The content of dencichine in the rhizome of P. zingiberensis and P. vienamensis var. fuscidiscus was significantly lower than that of the main root of P. notoginseng. It was also significantly lower than that of other parts of P. notoginseng, indicating that P. notoginseng was the best source of dencichine. The content of dencichine was mainly affected by species and parts, and had nothing to do with product specifications. The extraction method and HPLC detection method established in this paper could quickly and easily determine the content of dencichine. It can lay a foundation for the establishment of related standards of dencichine and provide a basis for the comprehensive utilization and development of P. notoginseng.

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    Ecology and Review
    Newly Recorded Species of Orchidaceae in Hainan, China
    YE Kang
    2019, 40 (11):  2261-2263.  doi: 10.3969/j.issn.1000-2561.2019.11.022
    Abstract ( 625 )   HTML ( 20 )   PDF (495KB) ( 661 )  

    Three species of Orchidaceae were newly recorded in Hainan. The newly recorded species were Cheirostylis takeoi (Hayata) Schltr, Nervilia lanyuensis S. S. Ying and Cryptostylis taiwaniana Masam. All voucher specimens were kept in Herbarium of Shanghai Chenshan Botanical Garden, Shanghai (CSH).

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    Resources Investigation, Conservation and Evaluation of Wild Mallotus oblongifolius in Hainan
    GU Wenliang,ZHUANG Huifa,WANG Hui,ZHANG Jianyu,QIN Yonglan,ZHANG Cuiling,QIN Xiaowei,TAN Lehe
    2019, 40 (11):  2264-2269.  doi: 10.3969/j.issn.1000-2561.2019.11.023
    Abstract ( 538 )   HTML ( 12 )   PDF (1366KB) ( 342 )  

    Mallotus oblongifolius is a substitute tea beverage plant and medicinal plant with local and national characteristics in Hainan. It has been developed as a popular tourism product now. But large-scale development and utilization of wild Mallotus oblongifolius without plan has caused great damage to its germplasm resources. Wild resources investigation, collection and conservation as well as evaluation of M. oblongifolius were carried out in this research. The results showed that among the 13 survey locations in 10 cities of Hainan, wild M. oblongifolius grown in only 2 locations were not artificially affected. The growth of M. oblongifolius in the other sites were destructed artificially. Total 285 germplasm resources of M. oblongifolius were collected and safely preserved in different places. Botanical identification and evaluation of 5 descriptive traits and 6 numerical traits were carried out on these 285 germplasm resources. The variation range of diversity index of descriptive traits was 0.69~1.74 and the variation range of diversity index of numerical traits was 1.93~2.11, which indicating that the collected and preserved germplasms had rich genetic diversity. This research would provide resource basis and evaluation data for artificial breeding of excellent M. oblongifolius cultivars.

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    The Communities and Species Diversity Features of the Cerbera manghas in Dazhou Island
    LYU Linling,CHEN Hui,LI Weijie,YANG Haijian,DAI Bo,HUANG Liangming,ZHENG Xilong
    2019, 40 (11):  2270-2277.  doi: 10.3969/j.issn.1000-2561.2019.11.024
    Abstract ( 551 )   HTML ( 15 )   PDF (656KB) ( 600 )  

    In this study, the features and species diversity of the Cerbera manghas communities in Dazhou Island, Wanning, Hainan were studied based on field investigation, in order to provide references for the germplasm conservation, the reasonable matching of coast shelter-forest species and the ecological restoration of mangrove forest. There were 62 species in 58 genera and 37 families of vascular plants in the quadrats. Cerbera manghas, Ardisia humilis, and Peristrophe bivalvis occupied the predominant position in the tree layer (36.45% of Importance Value (IV)), shrub layer (8.31% of IV) and herb layer (25.53% of IV) respectively. Flora of seed plant was dominant with tropic zone. The pantropic type was the most widely distributed form, with 27 families and 17 genera. The Margalef’s index, Shannon-Wiener index and Pielou’s index order of all layers in the community was shrub layer>tree layer>herb layer. The pattern of the Simpson index was shrub layer>herb layer>tree layer.

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    Threshold Effect of Soil Moisture on Photosynthetic Efficiency of Tomato Leaves at the Seedling Stage in Dry-hot Valley, Yunnan, China
    LI Jiancha,YAN Bangguo,PAN Zhixian,ZHANG Lei,YUE Xuewen,HE Guangxiong,FAN Bo,SHI Liangtao,FANG Haidong
    2019, 40 (11):  2278-2284.  doi: 10.3969/j.issn.1000-2561.2019.11.025
    Abstract ( 536 )   HTML ( 11 )   PDF (540KB) ( 356 )  

    Tomato plants were selected as the experimental material. Soil water gradients were obtained by the balances between water provision and consumption in experimental pots in a covered shed. The Li-6400 portable photosynthesis system was used to measure the photosynthetic efficiency parameters under different soil water conditions. It was found that the net photosynthetic rate (Pn), transpiration rate (Tr), water use efficiency (WUE) and photosynthetic parameters of tomato leaves had clear thresholds of soil moisture. Pn, Tr, WUE and stomatal limiting value (Ls) first increased and then decreased with decreasing soil water content, but their thresholds were different. The water saturation points of Pn and Tr were 18.18% and 20.68% respectively, the water efficiency point of WUE was 15.83%, and the maximum soil moisture of Ls was 10.74%. SOD activities of tomato roots and leaves increased significantly when soil water moisture was below 10.74%. The soil water of 10.74% was a critical point that the photosynthetic structure of tomato leaves was impaired, and it was also the maximum thershold point of soil water deficit allowed tomato seedling growth in the dry-hot valley. Soil moisture from 15.83% to 18.18% was classified as the intervals of high productivity and high efficiency; in this range, tomato had high photosynthetic capacity and efficient physiological characteristics for water consumption. This range of soil water meets to tomato production with high productivity and high efficiency in the dry-hot valley.

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    Distribution of Heavy Metal Contents in Soils of Main Crop Production Areas in Hainan and the Health Risk Assessment
    LIANG Jie,SUN Hongfei,GE Chengjun,MENG Lei
    2019, 40 (11):  2285-2293.  doi: 10.3969/j.issn.1000-2561.2019.11.026
    Abstract ( 2094 )   HTML ( 35 )   PDF (752KB) ( 457 )  

    The risk assessment in regards to the accumulation degree of heavy metals in soil (Cr, Cd, Pb, Cu, Ni and As), potential ecological hazards, and the health risks evolved from various exposure methods, including oral ingestion, inhalation and direct skin contact were conducted based on the soil samples obtained from the major crop growing areas in Hainan. The result revealed that in comparison with the risk thresholds suggested by the Soil Environmental Quality Risk Control Standard for Soil Contamination of Agricultural Land (Trial), the concentrations of Ni, Cd, Cr, Cu and Pb exceeded the thresholds in general whereas the highest exceeding which comes from Cd overtook the threshold by 307%; except for Cd, five heavy metals accumulated and incurred mild ecological hazards whereas Cd had a high accumulation degree and induced medium, critical or even severe ecological hazards in some particular areas. The indices for non-carcinogenic health risk of mentioned heavy metals were less than one; the carcinogenic health risks generated from As, Ni and Cr were acceptable. However, the health risks and carcinogenic risks were more severe for children than adults.

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    Soil Organic Carbon Distribution in Five Forest Types in the Northeast of Hainan Island
    XUE Yang,SU Shaofeng,LIN Zhipan,WANG Xiaoyan,CHEN Yiqing,XUE Yanwen,CHEN Pingmei
    2019, 40 (11):  2294-2299.  doi: 10.3969/j.issn.1000-2561.2019.11.027
    Abstract ( 521 )   HTML ( 9 )   PDF (504KB) ( 354 )  

    To reveal the soil organic carbon (SOC) distribution characteristics in different forest types in Northeastern Hainan, the data of SOC content and storage under five forest types (Pinus elliottii×P. caribaea, Casuarina equisetifolia, Cocos nucifera, Secondary forest and Mingled forest) in this region were analyzed. The results showed that in the 0-100 cm soil profile, the average SOC content of the five forests was significantly different (P<0.05). The highest was found in the secondary forest soil (3.78 g/kg), while in Casuarina equisetifolia the values were the minimum (0.90 g/kg); SOC storage values were 46.06 t/hm 2 in the secondary forest, 40.52 t/hm 2 in the mingled forest, 39.08 t/hm 2in Pinus elliottii×P. caribaea, 31.26 t/hm 2 in Cocosnucifera and 15.22 t/hm 2 in Casuarina equisetifolia. The secondary forests on shallow marine deposits and mingled forests on coastal sandy soil had relatively high SOC storage, which were significantly higher than Cocos nucifera and Casuarina equisetifolia on the same parent material respectively (P<0.05). In summary, the planting of different types of forests within this region would have a profound prospect on SOC storage, and the establishment of secondary forests and mingled forests may help the increment of SOC sequestration.

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    Research Progress of Silica Nanoparticle Effects on the Growth and Development of Plants
    SUN Dequan,LU Xinhua,HU Yulin,LI Weiming,DUAN Yajie,PANG Zhencai,HU Huigang
    2019, 40 (11):  2300-2311.  doi: 10.3969/j.issn.1000-2561.2019.11.028
    Abstract ( 657 )   HTML ( 22 )   PDF (532KB) ( 500 )  

    With the rapid development of nanotechnology, the interest in the applications of the technology in plants and agricultural sectors has increased. Among all the nano-materials, silica nanoparticles (SiNPs) are being widely used because of the unique structure and physicochemical properties. As the production and application of SiNPs continues to increase, they are inevitably discharged into the environment and conduct uncertain influences on plants and crop species. This paper mainly summarized in detail the researches on the interactions between SiNPs and plants, and the effects on the growth and development of plants in recent years. Firstly, the uptake and absorption of SiNPs by plants was introduced, and the transportation and distribution of SiNPs in plants was described. Then, the effects of SiNPs on each of the life cycle stages of plants including seed germination, seedling growth, seeding and production were present, and the physiological and molecular mechanisms of these impacts were explored. Meanwhile, the influences of SiNPs on plant stress resistance were documented and the reasons were given. In addition, the application of silica nano-fertilizers on plants especially crops and their effects were introduced. Finally, the problems such as the theoretical depth and further research directions in the study on the interactions between SiNPs and plants were mentioned. Therefore, suggestions were given in order to provide a reliable and in-depth theoretical basis for the safe and efficient utilization of SiNPs on agricultural sections.

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