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    25 December 2019, Volume 40 Issue 12 Previous Issue    Next Issue
    Crop Culture and Nutrition, Genetic Breeding
    Effects of Different N Rates on Storage and Remobilization of Urea- 15N by Rubber Tree
    ZHANG Yongfa,WU Xiaoping,WANG Wenbin,CHEN Yanbin,LUO Xuehua,XUE Xinxin,WANG Dapeng,ZHAO Chunmei
    2019, 40 (12):  2313-2320.  doi: 10.3969/j.issn.1000-2561.2019.12.001
    Abstract ( 602 )   HTML ( 17 )   PDF (435KB) ( 262 )  

    Two-year old young rubber trees were used as the materials. The soil transfer in leaf fall periods method and 15N isotope tracer technique were used to study the growth difference, nitrogen absorption, utilization and distribution characteristics of young rubber trees using three levels of N: less nitrogen (N28), proper nitrogen (N56) and over-dose nitrogen (N84). Results showed that the rational application rate of nitrogen fertilizer could promote the growth of young rubber trees in the current and following year. The N56 and N84 treatments promoted root growth and then above ground growth, and the N56 treatment had a better promotion effect than the N84 treatment on the shoot growth. The nitrogen use efficiency of rubber trees treatments with N28, N56 and N84 was 47.55%, 46.83% and 39.09%, respectively. After the first leaf stabilization period in the spring of the second year, the nitrogen use efficiency of each treatment was 44.49%, 43.79% and 38.17%, correspondingly. The main storage sites of nitrogen in young rubber trees were trunks and roots, with the 15N distribution rate of about 59.58%, and the 15N distribution rate in the xylem of trunks was the highest. That for the N28, N56 and N84 treatment was 24.65%, 28.69% and 25.50%, respectively. The 15N distribution rate of the ground shoots of the three treatments was N28 76.85%, N56 78.24% and N84 75.51%. After reuse in spring, the nitrogen absorbed and stored in the first year was transported to new organs (xylem of new shoots, bark of new shoots, leaves and petioles) in large quantities through branches and roots, meeting the needs of growth and development of seedlings. Among them, Ndff% of new growth organs of treatments with N28, N56 and N84 was the highest, 9.60%-11.31%, 18.39%-21.43% and 31.67%-34.04% respectively. However, Ndff% in the xylem of trunks was the lowest, 3.86%, 7.90% and 13.77% respectively. Nitrogen storage played an important role in the growth and development of the organs of young rubber trees in spring. The 15N distribution rates in the new growth organs of the three treatments was N28 50.60%, N56 53.98% and N84 53.28%. Under the appropriate nitrogen application level, the storage ratio of 15N in trunks and roots were higher, and the distribution ratio in new growth organs in the following year was also higher. This had a very important role in the seasonal recycling of nitrogen in young rubber trees and their growth and development.

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    Yield and Medicinal Quality of Clerodendranthus spicatus Intercropped under Rubber Plantation with Paired Row Planting System
    ZHENG Dinghua,CHEN Junming,CHEN Ping,ZHOU Lijun
    2019, 40 (12):  2321-2327.  doi: 10.3969/j.issn.1000-2561.2019.12.002
    Abstract ( 631 )   HTML ( 15 )   PDF (684KB) ( 267 )  

    The intercropping potential of Clerodendranthus spicatus under the rubber plantation with south-north paired row planting system, with cultivated in open field as CK, were studied, and the yield and main medicinal quality indexes of C. spicatus were assayed. The yield and medicinal quality were different with different treatments, different period and different plant parts. The yield of intercropped was much lower than that of CK. The highest yield of the middle and east side in the plantation treatments was 30% only that of CK. Although some extractive contents and ursolic acid contents were slightly higher than or similar to that of CK, the contents of crude flavonoids and rosmarinic acid as well as crude ash in the above-ground of the intercropped were less than that of CK, and the three indexes were worse when the shade density increased in rubber plantation simultaneously. By comprehensive consideration of yield and medicinal quality C. spicatus is not suitable for intercropping under the rubber plantation with south-north paired row planting system.

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    Preliminary Comparing of Agronomic Traits and Yield Between Three Different Banana Disease-resistant Varieties
    LIN Fei,SUN Peiguang,DING Zheli,HE Yingdui,LI Jingyang,WANG Lixia,HUANG Dongmei,TANG Fenling,WANG Bizun
    2019, 40 (12):  2328-2332.  doi: 10.3969/j.issn.1000-2561.2019.12.003
    Abstract ( 779 )   HTML ( 17 )   PDF (693KB) ( 334 )  

    Fusarium wilt is a global destructive disease for banana production, which can’t be effectively controlled. Breeding resistant varieties is one of the important measures to control it. The author conducted a plot experiment for three banana resistant varieties on the biological characteristics, agronomic traits, yield and morbidity. There were no big differences between ‘Nantian Huang’ and ‘Guikang 2’ varieties, but there were significant differences between ‘Zhongjiao 9’ and others. The growth period for ‘Nantian Huang’ and ‘Guikang 2’ was 383 and 393 days, separately, but the growth period for ‘Zhongjiao 9’ was 447 days. The agronomic traits for ‘Nantian Huang’ and ‘Guikang 2’ were not different obviously, and the short stalk, banana pesudostem height for the two was 285 and 298 cm separately. The average banana pesudostem for ‘Zhongjiao 9’ was 340 cm. The fruit index for ‘Nantian Huang’ and ‘Guikang 2’ was 21, and the fruit shape was moderate, which was similar to that of Banana Brazil. The fruit index was 16 for ‘Zhongjiao 9’, and the fruit shape was straighter and larger. The yield for ‘Zhongjia 9’ was the highest, which was 24.9 kg/bunch weight, and the yield for ‘Nantian Huang’ and ‘Guikang 2’ was 23.5 and 23.2 kg/bunch weight separately. The incidence rate of Fusarium wilt for ‘Nantian Huang’, ‘Guikang 2’ and ‘Zhongjiao 9’ was 0, 0.6% and 4.7% separately. In summary, ‘Nantian Huang’ and ‘Guikang 2’ are more suitable as Banana Fusarium wilt disease-resistant varieties, and more suitable for large-scale demonstration work for the future.

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    Effects of Different Chewing Cane-peanut Intercropping Treatments on Yield, Economic Benefit and Soil Physicochemical Properties
    LIU Yufeng,PAN Zengbao,SU Tianming,ZENG Chengcheng,LIANG Zhiheng
    2019, 40 (12):  2333-2340.  doi: 10.3969/j.issn.1000-2561.2019.12.004
    Abstract ( 471 )   HTML ( 13 )   PDF (793KB) ( 343 )  

    A one-factor field experiment of randomized block design was carried out to investigate the yield, economic benefit of chewing cane and peanut, as well as the soil physicochemical properties before planting (BP) and after harvest (AH) under different chewing cane-peanut intercropping treatments. Three intercropping treatments including chewing cane-peanut (1:2) intercropping (T2), chewing cane-peanut (1:1) intercropping (T1) and chewing cane mono-cropping (T0) were designed. Compared with T0, chewing cane-peanut intercropping patterns (T2 and T1) had no significant effect on the agronomic traits yield of chewing cane and peanut. Analysis results on the soil physicochemical index before planting (BP) and after harvest (AH) indicated that the chewing cane-peanut intercropping patterns could significantly increase soil organic matter and soil available nitrogen contents, but decrease soil available potassium contents, and the effect of T2 was more obvious than that of T1. The economic benefit of chewing cane-peanut intercropping patterns could significantly increase the total output and economic benefit. The benefits of chewing cane-peanut (1:2) intercropping (T2) was significantly higher than that of chewing cane-peanut (1:1) intercropping (T1). The land equivalent ratio (LER) of chewing cane-peanut intercropping patterns of T2 and T1 was 1.94 and 1.72, respectively. It is suggested that LER of chewing cane-peanut intercropping patterns was significantly higher than that of T0. The correlation analysis of output, cost and profit among the three chewing cane-peanut intercropping patterns showed that chewing cane-peanut intercropping partly increased planting cost, but significantly enhanced the gross output and profit. In conclusion, chewing cane-peanut (1:2) intercropping (T2) had minimal impact on the yield of chewing cane and peanut, and soil physicochemical properties, and also the best economic benefit among the treatments.

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    The Improvement of Aerosol Cultivation on Growth Potential and Root Absorption Ability of Tea Plants
    LOU Yanhua,SHU Zaifa,LIU Yu,JI Qingyong,SHAO Jingna,ZHENG Shenghong,HE Weizhong
    2019, 40 (12):  2341-2346.  doi: 10.3969/j.issn.1000-2561.2019.12.005
    Abstract ( 550 )   HTML ( 15 )   PDF (1717KB) ( 354 )  

    The influence of aerosol cultivation on the survival rate, chlorophyll SPAD value, growth potential and root absorption ability was studied by the comparison of four different tea varieties short branchlet cutting ( i.e. Bizaoxiang, Fudingdabai, Lizaoxiang and of Huiming No. 1) in this article. The cutting survival rate of the cultivars reached 96% with aerosol cultivation treatment. Chlorophyll SPAD, growth potential, root morphology and root activity of the cultivars showed significant difference. Chlorophyll SPAD, growth potential and root morphology increased over the cultivation time and showed the regularity as follows: Bizaoxiang > Fudingdabai > Lizaoxiang > Huiming No. 1. The root system activity reached the peak after rooting 30 days and showed the regularity as follows: 30 days after rooting > 40 days after rooting > 20 days after rooting > 10 days after rooting. Especially, Bizaoxiang exhibited the highest root system activity.

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    The Selection of Superior Trees and Analysis of the Genetic Diversity of Forty Years Old Seedling Forest of Camellia vietnamensis
    CHEN Jing,GUO Yujian,WANG Peixuan,WANG Hong,YANG Chengkun,ZHOU Kaibing
    2019, 40 (12):  2347-2355.  doi: 10.3969/j.issn.1000-2561.2019.12.006
    Abstract ( 495 )   HTML ( 12 )   PDF (521KB) ( 275 )  

    In order to select superior trees and discuss the genetic diversity among the forest of the adult Camellia vietnamensis seedling trees, surveys and experimental studies about agronomic characters, economic characters and quality characters were carried out in 32 high-yielding seedling trees from 40-year-old forest at Baomeiling Nature Reserve in Hainan. Results indicated that 20 trees proved to be high yield and rich in oil content; meanwhile, the physical-chemical properties and the fatty acid content of the seed oil are essentially in accordance with the quality standards of Oil-tea camellia seed oil (GB/T 11765-2018). The analysis of cluster based on the difference of agronomic characters, economic characters, physical-chemical properties and the fatty acid component demonstrated that the 32 high-yielding seedling trees could be clustered specially into 6 clusters (r 2=0.932), 10 clusters (r 2=0.864) and 7 clusters (r 2=0.937). Each of the three cluster-analysis can distinguish the abundance between different genotypes, and the 20 superior trees can be clustered respectively into all in 6 clusters, 7 in 10 clusters and all in 6 clusters, thus all of the results above illustrated that abundant genomic diversity existed in seedling trees, especially in the aspect of the abundance and genotypes. In conclusion, the breeding efforts should aim to high and stable yields. There are ones which can be expected to be cultivated into superior strains such as Jinbo 5 and 23. The genetic diversity of C. vietnamensis is very high, and some rare germplasm resources can be discovered for breeding.

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    Construction Strategy of Core Germplasm of Cherry Tomato
    NIU Yu,LIU Weixia,YANG Yan,LIU Ziji
    2019, 40 (12):  2356-2363.  doi: 10.3969/j.issn.1000-2561.2019.12.007
    Abstract ( 462 )   HTML ( 15 )   PDF (389KB) ( 277 )  

    In order to effectively identify the core germplasm and promote the innovative utilization of cherry tomato germplasm, the genotype values of seven traits (leaf length, leaf width, first inflorescence node, fruit length, fruit width, flesh thickness and weight per fruit) of 219 cherry tomato germplasms were predicted by a mixed linear model. Cherry tomato core germplasms were constructed based on genotype values by adopting two genetic distance (Euclidean distance and Mahalanobis distance), eight clustering methods (Single linkage, Complete linkage, Centroid method, Median method, Unweighted pair-group average, Flexible-beta method, Weighted pair-group average and Ward’s method) and three sampling methods (Preferred sampling, Random sampling and Deviation sampling) with 30% sampling proportion. The core germplasms constructed by different methods were evaluated based on mean, variance, range and variation coefficient. The variance of seven traits of cherry tomato core germplasm constructed by Euclidean distance and Mahalanobis distance were higher than that of the original population. By Euclidean distance, the means of seven traits had no significant difference between the core germplasms and the original population. By Mahalanobis distance, except four traits, the means of the other three traits were significantly different between the core germplasms and the original population. The result indicated that Euclidean distance was better than Mahalanobis distance. The variance and variation coefficient of seven traits of the core germplasms constructed by eight clustering methods were higher than that of the original population. The cherry tomato core germplasm constructed by the single linkage method had relatively larger genetic variation, which was better than the other clustering methods. The variance and variation coefficient of seven traits of the core germplasms constructed by three sampling methods were higher than that of the original population. The deviation sampling was superior to the preferred sampling and random sampling method. A total of 65 cherry tomato core germplasms were selected based on Euclidean distance, single linkage clustering and deviation sampling, which could represent the genetic diversity of the original population.

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    Quality Traits Diversity Analysis of Mallotus oblongifolius Germplasm Resources
    GU Wenliang,ZHANG Jianyu,QIN Yonglan,ZHUANG Huifa,WANG Hui,ZHANG Cuiling,TAN Lehe
    2019, 40 (12):  2364-2368.  doi: 10.3969/j.issn.1000-2561.2019.12.008
    Abstract ( 495 )   HTML ( 14 )   PDF (500KB) ( 252 )  

    The genetic diversity of five major quality traits including water extracts content, tea polyphenols content, free amino acid content, caffeine content and ammonia polyphenols ratio was analyzed by the principal component analysis and cluster analysis for 92 Mallotus oblongifolius germplasm resources from Hainan, China. The genetic diversity of the major quality traits of M. oblongifolius germplasms was abundant. The diversity index of the content of free amino acids was the highest, and that of the content of tea polyphenols was the second highest. The coefficient variation of the caffeine content was the highest, followed by the ammonia polyphenols ratio. The principal components analysis of the five quality traits revealed that the first two principal components accounted for 77.70% accumulation contribution rate, reflecting most of the information of the five traits. Based on the difference of the five quality traits between each resource, the 92 germplasms were divided into three groups. The third group had the best prominent antioxidant health care effect and the lowest caffeine content. It means that the third group could be used as a good material for breeding. Our results could provide a scientific basis for the utilization and breeding for excellent asexual strains of M. oblongifolius.

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    Phytophysiology and Biochemistry
    Physiological Responses and Evaluation of Cold Resistance under Cold Stress for Six Varieties of Eriobotrya japonica (Thunb.)
    PAN Cuiping,XIE Hongjiang,WANG Yongqing,ZHANG Hui,DENG Qunxian,YANG Zhiwu,WEN Lu,HE Shanshan
    2019, 40 (12):  2369-2374.  doi: 10.3969/j.issn.1000-2561.2019.12.009
    Abstract ( 760 )   HTML ( 18 )   PDF (572KB) ( 563 )  

    In order to investigate the physiological response and comprehensively assess cold resistance of different varieties under low stress, six varieties of Eriobotrya japonica (Thunb.) under cold stress were analyzed to determine the dynamic changes of relative electric conductivity (REC), malonadehyde (MDA), free proline (Pro), soluble sugar and soluble protein. The results showed that the relative electric conductivity (REC) in vitro seed embryos of young fruits of six loquat varieties presented an ‘S’ type curve change pattern as temperature decreased. The semi-lethal temperature of the six loquat varieties ranging from -4.759 to -2.73 ℃ using logistic equation, the semi-lethal temperature of white bud mutation was the highest and the Dawuxing loquat was the lowest among them. The contents of free proline (Pro) and malonadehyde (MDA) presented an inverted “V” type curve change pattern with the different time point of reaching the peak, which generally increased first and then decreased under cold stress. Furthermore, the soluble sugar and soluble protein increased as temperature decreased with the maximum value was obtained at the time of 24 h when treated at -5 ℃. The cold resistance ability of the six loquat varieties evaluated as WT (white bud mutation) > Guanyu > Ninghaibai > Longquan No.5 > Zaozhong No.6 > Dawuxing. In conclusion, the WT (white bud mutation) showed strong adaptability to low temperature stress and strong cold resistance. The median-lethal temperature combined with comprehensive evaluation based on subordinate function analysis could accurately identify the cold resistance of loquat varieties, which would provide a theoretical foundation and reference for screening of cold materials and looking for a new approach to increase the cold hardiness of loquat.

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    Analysis of Leaf Anatomical Structure of Wuyi Mingcong Tea Germplasm Resources
    WANG Feiquan,LI Jiyan,FENG Hua,LUO Shengcai,LIN Meijing,LI Shaohua,ZHNAG Jianming,ZHANG Bo,CHEN Rongbing
    2019, 40 (12):  2375-2389.  doi: 10.3969/j.issn.1000-2561.2019.12.010
    Abstract ( 904 )   HTML ( 10329 )   PDF (681KB) ( 1116 )  

    In order to identify and evaluate the leaf anatomical characteristics of tea germplasm resources in Wuyi Mountain tea region, the leaves of 70 Wuyi Mingcong tea germplasms were used as the materials for the comparative analysis of the anatomical structures and characteristics. There was abundant genetic variability in the 17 anatomical structure traits of the leaves of the 70 Wuyi Mingcong, with an average genetic diversity index of 1.85 and an average coefficient of variation of 17.64%. Strong stress resistance was found for all the germplasms. The mean value of the average membership function of drought resistance, disease and insect resistance and the average score of the cold resistance was 0.40, 0.39 and 1.28, respectively. Most of them were suited for making Oolong tea or green tea, while a few were suited for making black tea or both black and green tea. The average productivity index was 2648.85, indicating a higher potential productivity. The cluster analysis based on the anatomical structure traits of leaves showed that the 70 Wuyi Mingcong were divided into three groups. In addition to the thickness of upper and lower epidermis cuticle, the thickness ratio of upper epidermis to sponge tissue and the crystal number of calcium oxalate, other anatomical structure traits showed significantly or extremely significant difference among the three groups. The principal component analysis showed that the characteristic value of the former four principal components were bigger than one and represented 84.26% of the information of 17 anatomical structure traits of leaves. The composite scores of each Wuyi Mingcong were calculated based on the principal component and their corresponding characteristic value. The top ten Wuyi Mingcong had excellent comprehensive characters, which could be used in the development and innovative utilization of Oolong tea products, the selection and breeding of excellent tea varieties. The results were expected to provide references for the identification and utilization of local excellent tea germplasm resources and the breeding of new varieties in Wuyi Mountain.

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    Biotechnology and Tissue Culture
    Phylogenetic Analysis of Sweetpotato Germplasm Resources Based on SLAF-seq Technology
    LI Huifeng,HUANG Yongmei,LI Yanqing,HUA Jinfeng,WU Cuirong,FAN Jizheng,CHEN Tianyuan
    2019, 40 (12):  2390-2396.  doi: 10.3969/j.issn.1000-2561.2019.12.011
    Abstract ( 529 )   HTML ( 11 )   PDF (2156KB) ( 281 )  

    Based on SLAF-seq technology, 122 sweet potato germplasm resources were used to develop SNP sites, which were applied to the analysis of population structure and genetic evolution on all germplasm resources. Results showed that 563.18 Mb reads length was obtained by sequencing, the reads of the samples varied from 1 419 809 to 8 392 785. The sequencing quality value (Q30) changed from 90.61% to 96.82%, and the average Q30 was 92.78%. The GC content of the samples changed from 36.46%-40.33%, the average value was 38.17%, and that of the control was 40.72%. A total of 2 388 759 SLAF tags were developed, with an average sequencing depth of 17.45×. There were 77 761 polymorphic SLAF tags accounting for 3.26% of the total SLAF tags. Finally, 129 063 SNPs were found. The population structure and genetic evolution analysis showed that 122 germplasm resources could be divided into three groups, which was not directly related to the geographical source, and the results of clustering could provide scientific basis for parents combination and utilization of heterosis in sweetpotato breeding.

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    Cloning and Expression Analysis of Polygalacturonase-inhibiting Protein in Sisal
    ZHANG Yanmei,WANG Ruifang,YANG Ziping,LI Junfeng,LU Zhiwei,ZHAO Yanlong,LU Junying,ZHOU Wenzhao
    2019, 40 (12):  2397-2404.  doi: 10.3969/j.issn.1000-2561.2019.12.012
    Abstract ( 510 )   HTML ( 10 )   PDF (5084KB) ( 295 )  

    Polygalacturonase-inhibiting proteins (PGIPs), a group of plant defense proteins, play a crucial role in plant defense reaction. In order to excavate the important function of AhPGIPs, the study cloned AhPGIP1 and AhPGIP2 from H.11648 by PCR. The expression levels of AhPGIP1 and AhPGIP2 were analyzed in sisal H.11648 under several treatments, including Phytophthora nicotianae Breda, methyl jasmonate (MeJA), salicylic acid (SA), salt, low temperature and wounding by fluorescence quantitative PCR (qRT-PCR) technique. The results showed that the full-length cDNA of AhPGIP1 contained 1008 bp and was predicted to encode a protein of 335 amino acids with a theoretical molecular mass of 36.7 kDa and pI of 8.65. The full-length cDNA of AhPGIP2 contained 981 bp, and was predicted to encode a protein of 326 amino acids with a theoretical molecular mass of 35.8 kDa and pI of 8.98. The expression level of AhPGIP1 was not changed at 24 h and then significantly up-regulated by Phytophthora nicotianae Breda, and reached the max value after inoculating 48 h, and was up-regulated by MeJA, SA, salt, and wounding, and reached the max value after stresses 3, 12, 3 and 12 h, respectively. The expression level of AhPGIP1 was not changed by low temperature at 6 h and significantly down-regulated at 3, 12 and 24 h. The expression level of AhPGIP2 was significantly down-regulated at 24, 36 and 48 h and up-regulated at 72 h by Phytophthora nicotianae Breda, was significantly up-regulated by salt, low temperature, SA and MeJA, and reached the max value after stresses 3, 24, 3 and 12 h respectively. The expression level of AhPGIP2 was significantly up-regulated and reached the max value after stress 12 h by wounding, and significantly down-regulated after stress 3, 6, and 24 h. The study laid a solid foundation for further exploration of the function of AhPGIPs.

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    Transformation of Tissues of Litchi Fruit with Injection of Agrobacterium
    WANG Shujun,WANG Guo,LI Huanling,SUN Jinhua,LI Fang,WANG Jiabao
    2019, 40 (12):  2405-2410.  doi: 10.3969/j.issn.1000-2561.2019.12.013
    Abstract ( 792 )   HTML ( 13 )   PDF (1007KB) ( 329 )  

    To find an efficient transient gene expression method for litchi, the fruits of ‘Xinqiumili’ were used as the material to transform fruit tissues by Agrobacterium in this study. The effects of fruit developing stage, bacterium strains, injection sites, sampling time, bacteria solution concentration on the transformation efficiency were studied. The results showed that the GUS staining rates were better in four tissues under the condition that Agrobacterium strain GV3101 with OD600 of 2.4 was injected into the stalk, peel, seed and pulp of the stage Ⅱ b fruit with the pulp completely wrapped in the seed in vivo, and the fruits were sampled for detection after four days of injection. The transient gene expression system of litchi fruits was successfully established, which laid a foundation for the rapid identification of related genes of litchi fruits in the future.

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    Cloning and Expression of a Chitinase Gene SgGH19-1 from Stylosanthes and Its Enzymatic Properties Analysis
    LIU Pandao,WU Xique,LUO Jiajia,XU Wenrong,LIU Guodao
    2019, 40 (12):  2411-2417.  doi: 10.3969/j.issn.1000-2561.2019.12.014
    Abstract ( 489 )   HTML ( 8 )   PDF (899KB) ( 299 )  

    Chitin is a major component of the cell wall of fungi, exoskeleton of insects, and crustacean shells. Chitinase is one of the main hydrolase that catalyzes the degradation of chitin. Induction of PR-3 chitinase protein accumulation is an adaptive mechanism for plants to enhance the resistance to fungal diseases. Stylo (Stylosanthes spp.) is an important tropical forage legume. Although anthracnose caused by Colletotrichum gloeosporioides is one of the most destructive fungal diseases of stylo, little information is available regarding the responses of stylo chitinase during the pathogen infection. In the study, the PR-3 chitinase of stylo was characterized, and its expression pattern and biochemical properties were also analyzed. The results showed that a chitinase gene of PR-3 group in stylo was the cloned by homologous gene sequence method, and its coding region was 984 bp. The gene belongs to the Class I chitinase of the glycoside hydrolase 19 family, and was named SgGH19-1. Quantitative PCR analysis showed that the expression level of SgGH19-1 gene in the leaves of stylo was significantly increased after C. gloeosporioides infection, and with the increase of chitinase activity. Subsequently, the recombinant protein of SgGH19-1 was expressed and purified in Escherichia coli. Biochemical properties of SgGH19-1 showed both exochitinase and endochitinase activities, and the activities of endochitinase was 9.1 fold higher than that of exochitinase. Furthermore, the optimum pH and temperature for SgGH19-1 activity was 5.0 and 40 ℃ respectively. Taken together, SgGH19-1 is a chitinase that involved in the response of stylo to C. gloeosporioides attack. These results herein suggest that SgGH19-1 could potentially be employed as a new marker gene for developing cultivars of stylo with great tolerance to anthracnose.

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    Internal Reference Gene Actin of Setaria viridis and Its Application in Response to Different Drought and Salt Stress
    ZHANG Lili,ZHAO Hui,GUO Jingyuan,XIA Qiyu,HE Pingping,HUO Shanshan,QU Jing,FU Dongmei,GUO Anping
    2019, 40 (12):  2418-2425.  doi: 10.3969/j.issn.1000-2561.2019.12.015
    Abstract ( 473 )   HTML ( 11 )   PDF (1725KB) ( 498 )  

    In order to study the internal reference genes applied to the expression of different drought and salt stress genes in S. viridis, the cDNA sequence of 8 actin genes of S. viridis (accession A10.1) was obtained from https://phytozome.jgi.doe. gov/pz/portal.html. The primers for real time PCR were designed, and the templates of cDNA for the seedlings of S. viridis treated with different concentrations of drought and salt stress were used. Through the amplification fragment electrophoresis analysis, amplification curve and dissolution curve comprehensive analysis of RT-PCR, the results indicated that the actin gene corresponding to accession number Sevir.9G114100 was the most suitable internal standard gene among the eight actin genes. The practicability of the selected internal standard gene was verified. The results of the verification were consistent with the results of the transcriptome data, suggesting that the selected internal standard gene could be used in the verify experiments of S. viridis gene expression response to different drought and salt stress, giving a molecular base for further study of the functional gene of S. viridis.

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    The Expression Difference of Some Quantitative Characteristics of Okra (Abelmoschus esculentus) in Different Regions
    ZHANG Yiying,HUANG Zhicheng,ZHAO Hong,XU Li,LI Shouguo,GAO Ling,CHEN Hairong,REN Li
    2019, 40 (12):  2426-2431.  doi: 10.3969/j.issn.1000-2561.2019.12.016
    Abstract ( 549 )   HTML ( 8 )   PDF (547KB) ( 285 )  

    In order to investigate the effects of environmental conditions on the quantitative traits in okra, 16 okra varieties were used as the materials in different sowing sites. The results showed that the leaf length and leaf width fluctuated greatly among varieties and sites. Therefore, the two traits were more affected by the variety and environment. The petiole length was less varied among varieties, but it was greatly affected by the environment. Fruit thickness and fruit length were prone to instability among the varieties, 9.68% and 8.68% respectively, while the average coefficient variation (CV) of fruit length and fruit diameter among varieties was less significant. The number of seeds per pod had significant differences in different sowing sites, so it was susceptible to environment. Dwarf type, long fruit type, and red fruit type of okra were more susceptible to the environment than other types.

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    Crop Pests, Diseases and Their Control, Environmental Protection
    Trapping Effects of 12 Aggregation Pheromones on Rubber Bark Beetles
    CHEN Qing,LIANG Xiao,WU Chunling,CHEN Qian,ZHANG Zhe
    2019, 40 (12):  2432-2439.  doi: 10.3969/j.issn.1000-2561.2019.12.017
    Abstract ( 550 )   HTML ( 9 )   PDF (861KB) ( 335 )  

    This study aims to understand the trapping effects of 12 aggregation pheromones on rubber bark beetles. Field pest investigation together with one-way ANOVA multiple comparisons were used to compare the trapping effect of the aggregation pheromones. The results showed that the trapping effects of the 12 aggregation pheromones on rubber bark beetles were significantly different in different spacing and suspension heights of field traps. The trapping effects of 20, 35 and 50 m spacing were significantly higher than those of 65 m and 80 m spacing. The trapping effects of 2.0 m and 2.5 m suspension height were significantly higher than those of 1.5, 3.0 and 3.5 m. The trapping effects of (S)-(-)-ipsenol, (S)-(+)-ipsdienol, (4S)-cis-verbenol showed the best effect, the average number of traps per day of 20, 35 and 50 m was 56.89, 59.06 and 56.42, 54.69, 57.38 and 53.89, 51.27, 54.81 and 50.36, respectively; the average number of traps per day of 2.0 m and 2.5 m hanging height was 57.89 and 59.06, 53.77 and 57.38, 50.63 and 54.81, correspondingly, the percentage of the number of Xyleborus perforans and Xyleborus aquilus was 48.28% and 41.12%, 47.89% and 41.08%, 47.69% and 41.05%, separately, the average number of traps per day was 28.51 and 23.69, 27.48 and 23.00, 26.14 and 21.95, respectively. α-Pinene and dimethyl bark beetle bait also had better trapping effects on rubber bark beetles, the average number of traps per day of 20, 35 and 50 m spacing was 19.24, 22.16, 18.12 and 18.42, 20.96, 18.12, correspondingly; the average number of traps per day of 2.0 and 2.5 m hanging height was 18.23 and 22.16, 16.32 and 20.96, respectively; the percentage of the number of X. perforans and X. aquilus was 47.26% and 40.02%, 47.12% and 40.02%, separately, the average number of traps per day was 10.47 and 8.87, 9.88 and 8.39, respectively. With the increase of field time, the trapping effects of the 12 pheromones on rubber bark beetles increased gradually at first, reached the peak at 30 days, then decreased gradually, and decreased significantly after 60 days. (S)-(-)-ipsenol, (S)-(+)-ipsdienol and (4S)-cis-verbenol had the best trapping effects and α-pinene and dimethyl bark beetle bait had also good trapping effects on rubber bark beetle, and the suitable field spacing, suspension height and the effective period of the five aggregation pheromones was 35-50 m, 2.0-2.5 m and 60 d, correspondingly.

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    Expression Analysis of Genes Involved in Biosynthesis of Secondary Metabolites for Fusarium oxysporum f. sp. cubense in Response to Three Carbon Sources
    ZHAO Yanjuan,ZHAO Yajuan,LIU Junqi,JIN Tian,CHENG Mao,HUANG Liyu,WANG Zhenzhong,QIN Shiwen
    2019, 40 (12):  2440-2446.  doi: 10.3969/j.issn.1000-2561.2019.12.018
    Abstract ( 480 )   HTML ( 12 )   PDF (905KB) ( 306 )  

    To understand the pathogenesis mechanism of secondary metabolites for Fusarium oxysporum f. sp. cubense (Foc) during infection in banana, genes involved in the biosynthesis of secondary metabolites were predicted based on the transcriptome of Foc 1 and Foc 4 in response to different carbon sources, using antiSMASH and PHI-base database. 486 genes involved in the biosynthesis of secondary metabolites in the transcriptome were identified and sorted to 32 gene clusters, including 13 virulence-associated genes. Additionally, the gene expression pro?les involved in the biosynthesis of secondary metabolites of Foc 1 and Foc 4 in response to different carbon sources appeared remarkably different. A great majority of genes were differentially expressed in Foc when induced by host cell wall. Besides, more specific differentially expressed genes with high transcription level were identified in Foc 4 as comparison with Foc 1 during the degradation of banana cell wall. The results would provide a theoretical basis for understanding and studying the molecular pathogenesis mechanism of Foc.

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    Effects of smy1 Gene Knockout on Physiological Function of Fusarium oxysporum f. sp. cubense race 4
    HE Zhuang,QI Yanxiang,ZENG Fanyun,DING Zhaojian,LIANG Junwei,ZHANG Xin,PENG Jun,XIE Peilan,XIE Yixian
    2019, 40 (12):  2447-2455.  doi: 10.3969/j.issn.1000-2561.2019.12.019
    Abstract ( 507 )   HTML ( 10 )   PDF (17628KB) ( 167 )  

    Smy1 is a kinesin involved in the regulation of fungal growth. In the study, the smy1 kinesin gene of Fusarium oxysporum f. sp. cubense race 4 (Foc 4) was cloned. The smy1 knockout mutant of Foc 4 was obtained by homologous recombination technique. Besides observing the mycelial morphological characteristic, growth rate and sporulation of the mutants, pathogenicity to banana seedlings and sensitivity to fungicide were studied in order to reveal the role of smy1 played in the growth and development of F. oxysporum and resistance to fungicide. The results showed that, compared with the Foc 4 wild-type strain, the knockout mutants grew slowly, the mycelial morphology changed, the sporulation increased, and the pathogenicity to banana plantlets seedlings decreased, but the resistance level to fungicide changed little. This indicates that the smy1 gene may play an important role in the growth, sporulation and pathogenicity in Foc 4.

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    Genetic Diversity and Pathogenic Variability Among Isolates of Corynespora cassiicola from Tropical Crops in China
    LI Boxun,FENG Yanli,LIU Xianbao,CAI Jimiao,LU Cuimei,ZHENG Xiaolan,HUANG Guixiu
    2019, 40 (12):  2456-2465.  doi: 10.3969/j.issn.1000-2561.2019.12.020
    Abstract ( 482 )   HTML ( 8 )   PDF (2636KB) ( 321 )  

    Corynespora cassiicola is an important plant pathogenic fungus distributed globally and has a wide host range. In recent years, C. cassiicola had infected a variety of tropical crops. The diseases caused by C. cassiicola has outbroken in some areas, causing huge economic losses. In this study, we used ITS, EF-1α and β-tubulin genes to analyze the population diversity of isolates of C. cassiicola collected from rubber trees, cassava, papaya, tropical fruits and vegetables. When the similarity coefficient was 0.97, the tested isolate could be divided into two divergent clusters by the maximum likelihood method. Cluster I was the isolates of rubber trees, which came from China and some foreign countries, and cluster II was the isolates of other hosts. There was significant correlation between genetic clusters and host source. Pathogenicity test showed that the pathogenic differentiation of C. cassiicola was obvious. The isolates of cluster I could only infect rubber trees, but could not infect other hosts. They had obvious host specificity, and there was no significant difference in pathogenicity among isolates from different geographical sources. C. cassiicola in cluster II could infect each other among different hosts, but the pathogenicity and symptoms of the isolates were different, showing a high pathogenicity to the original hosts. The results of genetic diversity and pathogenic variability showed a good consistency, which would provide a theoretical basis for understanding the population structure and main pathogenic types among the isolates of C. cassiicola from tropical crops in China, as well as the occurrence, epidemic and control method of the diseases caused by C. cassiicola.

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    Effect of Plastic Film Mulching on the Ant Communities in Lemon Orchards
    YANG Jiandong,GUO Lina,WANG Ziran,GUO Jun,LI Jinxue,GAO Junyan
    2019, 40 (12):  2466-2473.  doi: 10.3969/j.issn.1000-2561.2019.12.021
    Abstract ( 392 )   HTML ( 9 )   PDF (712KB) ( 286 )  

    In order to explore the effects of plastic film mulching and conventional planting patterns on the ant communities, the ground-dwelling and canopy foraging ant communities were conducted by traps in different lemon orchards. The results showed that 35 ground-dwelling ant individuals, representing 6 species, 13 canopy foraging ant individuals, representing 5 species in the lemon orchardⅠ; 253 ground-dwelling ant individuals, representing 7 species, 67 canopy foraging ant individuals, representing 7 species in the lemon orchard Ⅱ; 159 ground-dwelling ant individuals, representing 7 species, 99 canopy foraging ant individuals, representing 6 species in the lemon orchard Ⅲ. There were significant differences of canopy foraging ant species richness and relative abundance, the species richness and relative abundance of canopy foraging ants of lemon orchard Ⅲ were significantly higher than lemon orchardⅠ. Ant community structures of lemon orchardⅠwere dissimilar with those in lemon orchard Ⅱ and Ⅲ. Monomorium orientale and Tapinoma melanocephalum were the indicator species of ground-dwelling ant in the lemon orchard Ⅱ, Odontoponera transversa was the indicator species of ground-dwelling ant in the lemon orchard Ⅲ; the indicator species of canopy foraging ants were Camponotus parius and T. melanocephalum of lemon orchard Ⅱ and Ⅲ, respectively. The results suggested that the ant communities of lemon orchards were affected by plastic film mulching, and plastic film mulching had temporal effects on the ant communities in lemon orchards.

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    Agricultural Product Processing, Preservation, Storage, Analysis and Detection
    Application of Principle Component Analysis of Fruit Storability Between Harvested ‘Nanfeng’ and ‘Xinyu’ Tangerines
    CHEN Chuying,LIU Shanjun,FU Yongqi,PENG Xuan,CHEN Jinyin
    2019, 40 (12):  2474-2480.  doi: 10.3969/j.issn.1000-2561.2019.12.022
    Abstract ( 429 )   HTML ( 11 )   PDF (761KB) ( 285 )  

    Cultivar is one of the most important factor affecting the storability of postharvest citrus fruit. Principle component analysis (PCA) was used to evaluate the difference of fruit storability between harvested ‘Nanfeng’ and ‘Xinyu’ tangerines, the two main cultivars of mandarin in Jiangxi Province. Fourteen physiological and biochemical indexes of decay rate, weight loss, citrus color index (CCI), browning index (BI), titrable acid (TA), vitamin C (VC), total soluble solid (TSS), total sugar, respiration rate, relative electrical conductivity (REC), antioxidant enzymes activities in ‘Nanfeng’ and ‘Xinyu’ tangerines during cold storage were statistically analyzed. Three important major constituents were selected, which representing 88.781% comprehensive information about the fruit storability of above two citrus cultivars. The first principal component was reflected the information of weight loss, CCI, BI, TA, respiration rate, REC, CAT and PPO. The second one was used to obtain the information of the decay rate, TSS, total sugar, SOD and POD. The third one was just expressed for VC content. PCA can be used to evaluate the difference of fruit storability between harvested ‘Nanfeng’ and ‘Xinyu’ tangerines. The fruit storability of ‘Nanfeng’ tangerine was superior to ‘Xinyu’ tangerine.

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    Effects and Mechanism of Calcium Chloride Treatment on Reducing Pineapple Black Rot
    GU Hui,JIA Zhiwei,HOU Xiaowan,ZHANG Lubin
    2019, 40 (12):  2481-2488.  doi: 10.3969/j.issn.1000-2561.2019.12.023
    Abstract ( 493 )   HTML ( 8 )   PDF (752KB) ( 291 )  

    In order to reduce the loss of pineapple fruit caused by black rot after harvest, the effects of calcium chloride treatment on black rot and related mechanism were studied in this paper. The results showed that 1% calcium chloride treatment had the best inhibitory and control effect. Calcium chloride treatment (1%) had little effect on the growth of mycelial, but could significantly inhibit the sporulation of pathogens. Calcium chloride treatment significantly reduced the enzymatic activities of PMG, CX and CB in the treated fruits, but had no significant effect on the changes of PG activity. Calcium chloride treatment significantly increased the content of H2O2 during the middle and late storage, and significantly increased the activities of resistance-related enzymes such as PAL, PPO, CHI and GLU. These results showed that calcium chloride treatment displayed effects on inhibiting black rot probably due to it reduced the pathogenicity of pathogens and induced disease resistance of treated pineapple fruits. Therefore, the appropriate concentration of calcium chloride treatment would provide a new way for the green control of pineapple black rot after harvest.

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    Comparison of Dissolved Organic Matter from Biochar on Attenuating Biotoxicity of Oxytetracycline
    GE Chengjun,ZHAO Yuanyuan,YU Huamei,YUE Lin,FU Yue,MA Ruiyang,CHENG Lei
    2019, 40 (12):  2489-2497.  doi: 10.3969/j.issn.1000-2561.2019.12.024
    Abstract ( 396 )   HTML ( 6 )   PDF (2500KB) ( 269 )  

    In order to explore and state the possibility effects of dissolved organic matter (DOM) on the biotoxicity of oxytetracycline (OTC), aqueous solution and soil culture incubation experiments were conducted to investigate the effects of DOM extracted from biochar, derived from the cassava residue at 350 ℃, 500 ℃, 650 ℃, on the pakchoi (Brassica rapa var. glabra) seed germination, root and bud elongation. Results showed that DOM350 and DOM500 had a promoting effect on seed germination rate of Brassica rapa var. glabra in hydroponic and soil culture condition, which was 3.33% and 10.00%, respectively. For DOM-OTC system, there was a significant correlation between DOM concentrations and bud elongation of pakchoi (B. rapa var. glabra) seeds (P<0.05). Furthermore, DOM had a synergistic effect with low concentration (<34.78 mg/kg) of OTC to promote root and bud extension of seeds, and antagonized the biotoxicity of OTC with high concentration (>94.09 mg/kg) of OTC. However, DOM alleviated the toxicity of OTC on root elongation rate, and had a highly significant effect on shoot elongation of seeds cultured in water (P<0.01), when DOC concentration at 10 mg/L.

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    Composition of Essential oils and Hydrosols Acquired from Alpinia officinarum Hance by Supercritical CO2 Extraction and Steam Extraction
    LIN Lijing,HUANG Xiaobing,LIU Mengjie,LI Jihua
    2019, 40 (12):  2498-2504.  doi: 10.3969/j.issn.1000-2561.2019.12.025
    Abstract ( 538 )   HTML ( 18 )   PDF (517KB) ( 382 )  

    The essential oils and hydrosols were acquired from Alpinia officinalis Hance by supercritical CO2 extraction and steam extraction, and the extraction rate and appearance color of the oils and hydrosols were analyzed. The components of the samples were analyzed by gas chromatography-mass spectrometry (GC-MS). The results showed that the yield of the essential oil and hydrosols extracted by supercritical CO2 was higher than that by steam extraction, and there was no difference in the appearance color of hydrosols. There were 35 components of essential oils and 20 components of hydrosols extracted by supercritical CO2 technology, and 29 components of essential oil and 19 components of hydrosols extracted by steam extraction. The components extracted by the two methods were different. The relative content of 1,8-eucalyptin in the oils extracted by supercritical fluid was 15.49%, and that extracted by steam was 10.61%. The highest content of hydrosols extracted by supercritical fluid was limonene, with a relative content of 68.50%. The highest content of hydrosols extracted by steam was 1,8-eucalyptin, with a relative content of 31.83%. The experimental results could provide a theoretical basis for the extraction of essential oils and hydrosols of A. officinalis Hance.

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    Two-Step Fermentation Technology of Passionfruit Pericarp
    ZHANG Shun,HUANG Wei
    2019, 40 (12):  2505-2511.  doi: 10.3969/j.issn.1000-2561.2019.12.026
    Abstract ( 558 )   HTML ( 7 )   PDF (632KB) ( 274 )  

    The two-step fermentation process of Saccharomyces cerevisiae and lactic acid bacteria was studied to prepare passionfruit pericarp pulp with high viability of lactic acid bacteria and Saccharomyces cerevisiae, good retention of polyphenols and mellow flavor. Through single factor and orthogonal experiments, the fermentation process parameters of single lactic acid bacteria and yeast were optimized by taking the number of live S. cerevisiae and lactic acid bacteria, total phenol and ethanol production as the indexes. On this basis, by measuring the changes of total acid content, viable bacteria number and total phenol content, the technological parameters of the two-step fermentation of passionflower pericarp pulp were determined. The total fermentation time was 40 h. The initial inoculation amount of the mother bacteria was 1.5%. After 16 h of fermentation at 29 ℃, 2.0% mixed Lactobacillus (L. caseiL. plantarum = 1∶1) was added, and the fermentation continued at 37 ℃ for 24 h. In the fermentation broth, the number of live Lactobacillus was 8.9 lg CFU/mL, the number of live S. cerevisiae was 7.78 lg CFU/mL, the total phenol content was 24.0 μg/mL, and the total acid content was 4.4 mg/mL. The two-step fermentation method had the advantages of S. cerevisiae producing aroma, ethanol inhibiting impurities, and lactic acid bacteria improving acidity and retaining polyphenols.

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    Determination of Dimethomorph and Gibberellin A3 Residues in Fruits and Vegetables by Liquid Chromatography
    GUO Hongbin,WANG Mingyue,ZHANG Chunyan,LIN Ling,YE Jianzhi,YANG Chunliang
    2019, 40 (12):  2512-2518.  doi: 10.3969/j.issn.1000-2561.2019.12.027
    Abstract ( 435 )   HTML ( 16 )   PDF (606KB) ( 346 )  

    A simple, sensitive and reproducible high-performance liquid chromatographic method was developed for determining dimethomorph and gibberellin A3 residues in fruit and vegetable samples (strawberry, watermelon and tomatoes). The samples were extracted with ethyl acetate under acid conditions (pH 2.5), cleaned up by florisil solid-phase extraction cartridge, and analyzed by high-performance liquid chromatography with ultraviolet detection. There were good linear correlations between the peak area and the corresponding concentration of dimethomorph and gibberellin A3 in the range of 0.025-1.00 μg/mL and the correlation coefficient was above 0.9995. The average recovery of dimethomorph and gibberellin A3 in three levels (0.025, 0.050 and 0.100 mg/kg) was between 81.2 and 91.3. The limit of detection of the dimethomorph and gibberellin A3 was 0.01 mg/kg and 0.02 mg/kg, respectively.

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    Research Progress and Prospect Analysis of Sandponics
    MU Dawei,ZHENG Jie,WANG Qin,AI Tengteng
    2019, 40 (12):  2519-2527.  doi: 10.3969/j.issn.1000-2561.2019.12.028
    Abstract ( 855 )   HTML ( 205 )   PDF (1160KB) ( 618 )  

    Sandponics, an eco-friendly, low-cost, low-tech soilless cultivation technique, accords with national condition of China and soilless culture development of world. The paper illuminates the Sandponics system composition and states sand substrates indexes including particle size, salt content, mud content and acidity-alkalinity. Element requirements of nutrient solution is explored and sustainable theory of the Sandponics is analyzed. The paper builds up the Sandponics technique standard to provide reference for production practices and future studies. The paper analyzes nutritional quality of vegetables cultured with the Sandponics, including sugar content, nitrite content and heavy metal content. The characteristics of the Sandponics and its ecological significance and social significance were claimed. The paper analyzes the prospect of the Sandponics in the Urban Agriculture and the South Sea Islands.

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