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    Crop Culture and Nutrition, Genetic Breeding
  • Crop Culture and Nutrition, Genetic Breeding
    WU Min,WEI Jiashao,HE Peng,WU Bingsun,WU Wenguan,GAO Le,WANG Guihua,SUN Yong
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    The differences of nutrient contents of young stems and soil physicochemical properties were compared with CK after applying humic acid nutrient modifier (HANM) in 2906, 4100 and 5415 kg/hm 2 by a randomized block test in order to supply a theoretical direction for soil fertility management in pitaya fruit orchards. Soil nutrient contents of total nitrogen (TN), total phosphorus (TP), total potassium (TK), soil alkali-hydrolyzable nitrogen (AN), available phosphorus (AP) and available potassium (AK) did not decrease in the treatments with 13.40%, 18.90% and 24.96% of the fertilizer amounts of the control if HANM was used. Application of HANM in 5415 kg/hm 2obviously increased the contents of AK and organic matter (OM) in dressing furrow. Application of HANM did not decrease soil pH and nutrient contents of young stems in pitaya fruit. HANM can be used in pitaya fruit orchards in order to decrease fertilizer usages, stabilize soil fertility and guarantee the nutrient demand of pitaya fruit.

  • Crop Culture and Nutrition, Genetic Breeding
    QIU Quanmin,WANG Wei,WU Xuehua,ZHOU Changmin,BAI Cuihua,YAO Lixian
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    Typical acid soil from a litchi orchard was collected to conduct a soil incubation and a litchi pot experiment in a greenhouse to examine the response of soil attributes and litchi growth to soil pH conditioners, and to select suitable soil pH conditioners for litchi production. Lime (1 g/kg), dolomite (2 g/kg) and calcium magnesium phosphate (0.625 g/kg and 4 g/kg) were used respectively. The soils without conditioners were used as the control. The application of soil conditioners enhanced soil pH at different extents, and the influence on the availability of soil macro-, secondary and micro-nutrients, soil enzyme activities and litchi growth was associated with the type and use rate of conditioners and soil properties themselves. Generally, the usage of lime, dolomite and high dose of calcium magnesium phosphate obviously promoted the growth of litchi seedlings. Moreover, lime and dolomite exhibited better performance than calcium magnesium phosphate did with high dose. However, low dose of calcium magnesium phosphate inhibited litchi growth. It is suggested that lime and dolomite are practical soil pH conditioners in acid litchi orchards. The suitability of calcium magnesium phosphate as a soil pH conditioner and its proper use rate are dependent on the soil property of the target litchi orchard.

  • Crop Culture and Nutrition, Genetic Breeding
    ZHAN Shan,YUAN Hong,DU Tiantian,REN Wei,KUANG Huiwu,SONG Hongfu,SHENG Hao
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    The amplification effect of soil acid and alkali buffering ability, as well as the decreasing of available cadmium (ACd), was studied using a long-term positioning experiment of paddy soil in organic fertilizer, conditioner and lime in heavy metal contaminated restoration areas. Compared with CK, soil pH increased by 0.1-0.4 units, or by 5.62%-8.67%, and the improving effect was in a downtrend for lime, organic fertilizer and conditioner. The total cadmium (TCd) and ACd content of paddy soil decreased with the three treatments ranged between 0.24%-19.24% and 3.48%-11.01% respectively. Among them, the effect of the organic fertilizer treatment was better than that of the lime treatment, while that of the conditioner was the worst. The buffering capacity to soil acid and alkali was amplified for lime, organic fertilizer and conditioner in a downtrend. Soil fertility could be effectively improved by the three treatments, and the available phosphorus content increased significantly (P<0.05). The paddy soil buffering capacity in the study area was closely related to pH, total exchange acid, and other soil nutrient factors.

  • Crop Culture and Nutrition, Genetic Breeding
    LI Shaowei,YIN Guangtian,YANG Jinchang,LI Rongsheng,ZOU Wentao,YU Niu,WANG Zhihai
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    In order to screen out the optimal fertilizer combination of nitrogen, phosphorus and potassium for Mytilaria laosensis container seedling, an orthogonal experiment design with five factors and four levels was established on height, ground diameter, biomass and nutrient utilization. Different fertilizer combination had significant effects on the height, ground diameter, total biomass of container seedlings, indicating the promoting effects of fertilization formula on the growth of container seedlings. The effects of N, P, K on the height of container seedlings were N>P>K with the optimal combination of N1P3K2 (50 mg N+50 mg P+60 mg K per plant) while the effects of those on the ground diameter growth and biomass accumulation were N>K>P, and the best combination for the ground diameter growth and biomass accumulation was N1P4K2 (50 mg N+60 mg P+60 mg K per plant) and N1P4K1 (50 mg N+60 mg P+45 mg K per plant) correspondingly. Rational formula fertilization effectively improved the efficiency of nutrient exploitation of the seedlings. Conclusively, the optimal fertilizer formula for the seedlings growth of M. laosensis was N1P4K1 (50 mg N+60 mg P+45 mg K per plant) based on the comprehensive growth indices.

  • Crop Culture and Nutrition, Genetic Breeding
    LEI Fei,TAN Hao,XIAO Tongbin,FU Chuangliang,LIU Guobiao,ZHANG Dongming,WU Jiayu,ZHANG Wen
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    In order to understand the improvement effects of Zea mays on the secondary salinization of vegetable greenhouse soil, five cultivars of Z. mays (Xianyunuo 2, Taixi 2, Taixi 3, Bohong 5 and Meilan 16) were selected to study the nutrient accumulation of maize and the variation of soil nutrient, secondary salinization in different soil layers. The total biomass, nitrogen uptake, phosphorus uptake, calcium uptake and magnesium uptake of Xianyunuo 2 were the highest, which was 714.94, 12.30, 2.70, 6.11 and 1.13 kg/667 m 2, respectively. Compared with no catch crop, maize palnting could reduce the content of soil available N, available P, available K, exchangeable calcium, exchangeable magnesium in the 0-20 cm soil layer, and the reduction of soil available N, available P, exchangeable calcium, exchangeable magnesium content of Xianyunuo 2 were bigger than those of the other cultivars. Soil EC of the 0-20 cm soil layer dropped by 15.18% to 35.43% after the five cultivars planted, and Xianyunuo 2 showed the largest decline. Therefore, in the interim period of vegetable greenhouse, planting maize could reduce soil nutrient accumulation and remit soil secondary salinization.

  • Crop Culture and Nutrition, Genetic Breeding
    SUN Yanbo,ZHU Zhixin,HUANG Ting,LI Siming,ZHU Guopeng
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    In this study, the main sweet potato varieties planted in tropical areas, including ‘Xinxiang’, ‘Guangshu 87’, ‘Chuanshan Zi’, ‘Ning Zishu 1’, ‘Shulv 1’, ‘Gaoxi 14’ and ‘Sanjiao Ning’ were used as the materials. The selection of explants, disinfection schemes, medium formulation and anti-browning agent were explored. The optimum regeneration system of virus-free and rapid propagation was established for the main sweet potato varieties. The proliferation rate and survival rate of lateral buds were the highest among different parts of explants. In treatments of different explant disinfection, 75% alcohol for 60 s, 2% sodium hypochlorite for 15 min, and 0.1% mercury chloride for 15 min exhibited the lowest contamination rate. The medium formula with the shortest rooting time was as follows: MS+0.05 mg/L NAA+0.1 mg/L GA3. The medium formula with the fastest growth of stem length was as follows: MS+0.1 mg/L NAA+1 mg/L 6-BA+0.5 mg/L GA3. The medium formula with the fastest growth rate of dry weight was as follows: MS+0.1 mg/L NAA+1.5 mg/L 6-BA+0.5 mg/L GA3. Adding 5-6 g/L sodium thiosulfate and 1.25 g/L polyvinylpyrrolidone to the medium could effectively inhibit the browning of explants.

  • Crop Culture and Nutrition, Genetic Breeding
    WANG Shujun,SUN Jinhua,LI Huanling,WANG Guo,LI Fang,WANG Jiabao
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    In order to develop a new gene transformation pathway for litchi, the female flowers of Xinqiumili (24 h after pollination) were transformed by the pollen tube pathway method, using GUS as a report gene, and the fruit set percentage, seeding rate, and conversion rate were counted. A total number of 303 seedlings were obtained, and four positive transformed plants were verified according to PCR analysis and GUS staining, the transformation rate was 1.32%. This study would provide a simple and efficient way for the biotechnology breeding of litchi.

  • Crop Culture and Nutrition, Genetic Breeding
    SU Qun,YANG Yahan,TIAN Min,BU Zhaoyang,MAO Liyan,ZHANG Jinzhong,PAN Jiechun,LU Jiashi
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    The genetic diversity of 46 waterlily germplasm resources introduced within China and abroad was analyzed by the ISSR molecular marker technology, and the DNA fingerprints of the original species and varieties were constructed in order to clarify the genetic relationship and provide a theoretical basis for the classification and identification of waterlily, hybrid breeding and functional gene mining, utilization and map-based cloning. The results showed that 10 primers with high polymorphism and good repeatability were screened out from 100 ISSR primers. A total of 281 bands were amplified from 46 waterlily germplasm resources, with an average of 28.1 bands per primer, 281 polymorphic bands and 100% polymorphic ratio. The average Shannon information index (I) was 0.4197, the average Nei's gene diversity index (H) was 0.2657, and the average effective allele number (N) was 1.4139, which showed abundant genetic diversity. The genetic similarity coefficient was between 0.51 and 0.98. Based on the genetic similarity coefficient, a clustering tree was constructed to reveal the genetic relationship of the 46 waterlily germplasm resources. When the similarity coefficient was 0.68, all the tested materials could be clustered into six groups. DNA fingerprints were constructed for 24 original species and varieties of waterlily, and different waterlily germplasms could be identified according to the differences of DNA fingerprints.

  • Phytophysiology and Biochemistry
  • Phytophysiology and Biochemistry
    WU Baoduo,TANG Hu,HU Lisong,FAN Rui,YANG Jianfeng,ZHOU Yanfei,HAO Chaoyun
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    Piper nigrum cv. Reyin1 is widely planted in China and is sensitive to cold stress. Five different concentrations of calcium chloride treatments including 0, 7, 14, 21, 28 mmol/L were set to spray black pepper. All the materials were treated with low temperature (10 ℃/5 ℃, 12 h/12 h) for four days and recovery training (28 ℃/20 ℃, 12 h/12 h) for six days. The phenotype and physiological indexes were analyzed. Calcium chloride treatment of 7 mmol/L could improve the cold damage phenotype and net photosynthetic rate of black pepper. With Ca 2+ concentration increasing, the cold damage phenotype gradually aggravated and net photosynthetic rate became lower. Compared with CK, the 7 mmol/L Ca 2+ treatment could significantly improve the activity of antioxidant enzymes, increase the soluble sugar content and reduce the malondialdehyde content. With the Ca 2+ treatment concentration increasing, the activity of antioxidant enzymes and the soluble sugar content became lower, and the malondialdehyde content became higher. The results would provide a reference for cold resistance technical guidance and cold resistance molecular breeding in black pepper production.

  • Phytophysiology and Biochemistry
    WANG Hong,YANG Chengkun,YUE Kun,GUO Yujian,ZHOU Kaibing
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    In order to evaluate the injures and responses of the anti-oxidation of mango fruits under two different doses of enhanced UV-B radiation treatments, the adult trees of the variety ‘Tainong No. 1’ in the field were treated with enhanced UV-B radiation at the levels of 24 kJ/(m 2·d) and 96 kJ/(m 2·d), and those with natural sunlight were used as the control (CK). The dynamic changes of physiological and biochemical indexes related to plant yield, fruit quality and physiological damage, antioxidant protection mechanism, etc. were observed. The results showed that the yield per tree and single fruit weight of 96 kJ/(m 2·d) was significantly decreased compared with CK, and the fruit soluble sugar was decreased, titratable acid content was increased, and then the sugar-acid ratio was decreased, resulting in the fruit quality was worse. The content of MDA in the pericarp of two UV-B radiation treatments was not significantly different from CK, but the flesh was significantly higher than the CK. The contents of vitamin C and unknown compounds in pericarp treated with 96 kJ/(m 2·d) were significantly higher than the CK, while the POD activity was significantly lower than the CK, and there was no significant effect on the activity of other antioxidant enzymes and content of reductive protective components. The antioxidant enzyme activity and reduced GSH content of the flesh treated with two UV-B radiations increased first and then decreased with time. Compared with CK, the activity of SOD and CAT in the flesh treated with UV-B radiation were significantly decreased. POD activities, flavonoids and reduced GSH contents in the flesh treated by 96 kJ/(m 2·d) were significantly lower than the CK, while POD activities treated by 24 kJ/(m 2·d) showed no significant difference from CK. Flavonoids and reduced GSH contents was significantly lower than the CK only in the post-ripping stage, while polyphenol contents was almost unaffected. It can be seen that enhanced UV-B radiation [96 kJ/(m 2·d)] caused damage to the tree body and flesh, but no damage to the pericarp.

  • Biotechnology and Tissue Culture
  • Biotechnology and Tissue Culture
    SUN Xiwei,FAN Haikuo,Gong Shufang,LIU Rui,JIU Fengfeng,XIAO Yong
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    ZF-HD protein is a family of transcription factors that contain zinc finger domains and only exist in plants. It not only regulates the growth and development of plants, but also plays an important role in floristic response to stress. In this study, 20 ZF-HD proteins of coconut were identified by comparison with the developed coconut genome database. Bioinformatics methods were used to analyze its genic structure, protein physicochemical properties, protein conserved domains, motifs, phylogenetic trees and expression profiles. The analysis showed that the coconut ZF-HD proteins are mostly basic protein. And they are mainly located in the nucleus, chloroplast and mitochondria. The coconut ZF-HD gene family could be divided into 6 subfamilies, each of which had similar structural domains and super secondary structures. The motif search analysis showed that the CoMIF subfamily only contained the zinc finger domain conserved sequence, and the other subfamilies contained the zinc finger domain sequence and the homeobox domain sequence. And expression profiling revealed that CoZHD18 and CoZHD20 were not detected in the sequenced tissues, and the expression levels of other family members in each tissue were different.

  • Biotechnology and Tissue Culture
    XU Xiaoping,XIE Yanping,CHEN Fanglan,CHEN Xiaohui,CHEN Yukun,ZHANG Zihao,CHEN Chunzhen,LIN Yuling,LAI Zhongxiong
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    The tissue culture seedlings of a wild banana germplasm from Sanming were used to clone the cDNA and gDNA sequences of β-1,3-glucanase gene Mugsp7 by RT-PCR. Bioinformatics and qRT-PCR analysis of the expression at different low temperature were also carried out, and the enzyme activity of mperatureureent lowthe leaves was further determined by treating at 8 ℃ for 1, 2, 3, 4 and 5 days. The gDNA sequence of Mugsp7 was 1132 bp with an open reading frame (ORF) of 984 bp and one intron of 148 bp, which encoding 327 amino acids. Bioinformatics analysis showed that Mugsp7 was an acidic hydrophobic stable protein, and there was no signal peptide. The amino acid sequence of Mugsp7 shared significant similarity with that in Musa acuminata, Zostera marina, Maize, Hordeum vulgare L , Oryza sativa on the same branch, and it was closely related to Musa acuminata. The expression pattern of Mugsp7 under different low temperature treatments was different, suggesting that Mugsp7 was a low temperature stress related gene.

  • Biotechnology and Tissue Culture
    CHEN Yonggan,GU Fenglin,CAI Yingying,XU Fei,ZHU Kexue
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    The full length of bgl of Bacillus sp. XY18 and Bacillus sp. XY20 was amplified by RACE. The recombinant vectors pET28a (+)/bgl and pET28b (+)/bgl were constructed, then transferred into E. coli BL21 for induction expression, and the protein was purified by Ni affinity chromatography. The enzymatic properties of the two proteins were determined. The two proteins were weak acidic proteins, and the enzyme activity reached the maximum at 40 ℃ with certain heat resistance, suggesting that appropriate weak acid condition and temperature could be provided to optimize the vanilla curing process.

  • Biotechnology and Tissue Culture
    CHEN Shu,ZHAO Qiufang,CHEN Hongliang,JIN Hui
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    Ubiquitin-binding enzyme is an important component of the ubiquitin/proteasome pathway, playing an important role in protein ubiquitination. In this study, bioinformatics tools were used to systematically analyze the maize gene structure and evolution relationship of ubiquitin E2 family members. Phylogenetic analysis showed that the maize ubiquitin-binding enzyme genes could be divided into six subfamilies. The number of the members in each subfamily is different. Subfamily UBC1 contained the largest numbers (22 genes), while the least number of members was UBC3, only five genes. Based on the subfamily UBC2, it was found that there were four paralogous genes in UBC2, namely ZmUBC3/ZmUBC70, ZmUBC8/ZmUBC34, ZmUBC31/ZmUBC53 and ZmUBC45/ZmUBC66. Gene structure analysis revealed that the paralogous genes were similar in structure. ZmUBC45/ZmUBC66 contained the largest number of exons (9 exons) while ZmUBC31/ZmUBC53 only had four. Gene motif analysis results showed ZmUBC3/ZmUBC70 contained eight motifs while ZmUBC8/ZmUBC34 and ZmUBC31/ZmUBC53 only had three. Gene promoter element analysis revealed that there were five component types, which were photo response elements, hormone response elements, stress response elements, tissue expression related components, and periodic regulation related components. Gene expression analysis indicated that all the tested genes had high expression levels in the female flowers but the lowest expression in roots and stems. The low nitrogen stress test suggested that the relative expression of all the tested genes decreased rapidly to a minimum at 1th hour, then increased slowly. Under low concentration of NH4 + treatment, the expression level of each gene gradually decreased and reached the lowest value at the 24th hour point. The results suggested that the maize ubiquitin-binding enzyme genes may be involved in the response of low nitrogen stress pathway.

  • Biotechnology and Tissue Culture
    YUAN Xiuyun,XU Shenping,ZHANG Yan,WANG Mofei,JIANG Suhua,LIANG Fang,CUI Bo
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    To study the molecular regulation mechanism of Phalaenopsis in response to low temperature stress, a cyclophilin gene PhCyP (GenBank accession number: MH992514) was cloned from the leaf of Phalaenopsis through the RT-PCR and RACE method. The full-length cDNA sequence was 829 bp with an open reading frame (ORF) of 522 bp encoding 173 amino acids. PhCyP contained a cyclophilin-like domain (CLD) with alkaline and hydrophilic properties. The phylogenetic tree showed that PhCyP was closely related to the cyclophilin from Phalaenopsis equestris, Vanda hybrid cultivar, Apostasia shenzhenica and Dendrobium catenatum in Orchidaceae. The expression analysis showed that PhCyP was highly expressed in different tissues including root, leaf, flower, ovary and seed in different development stage. Under 13 ℃/8 ℃ day/night temperature, the expression level of PhCyP reduced gradually with treatment time and was the lowest at 6 d, then increased gradually from 9 d to restoring. Under 4 ℃ treatment, the expression level of PhCyP increased gradually, and achieved the highest level at 4 h, then its expression level decreased gradually with a lower level than that before treatment at 48 h. The results suggested that PhCyP was involved in the response to low temperature stress with different molecular regulation mechanism to different low temperature stress.

  • Biotechnology and Tissue Culture
    ZHOU Niannian,GAO Jie,DING Mingzhu,AN Yulan,ZHAI Keqing,SHI Jiayin,GAN Defang,LIU Wen
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    New photovoltaic agriculture can generate photovoltaic power under the light demand of crop growth. To study the differential gene expression in lettuce leaves under different spectrophotometric films, the ‘Adina’ lettuce variety was used as the experimental material, and the gene expression level of lettuce leaves under the conditions of red and blue filter film (RBFF) and far infrared cut-off film (RICF) was analyzed by the transcriptome sequencing (RNA-seq) technique. The results showed that 2685 genes were differentially expressed in RBFF, including 1380 up-regulated genes and 1305 down-regulated genes; 3264 genes were differentially expressed in RICF, of which 881 were up-regulation and 2383 down-regulation. Further analysis revealed that 1498 differentially expressed genes were expressed in both RBFF and RICF, 1187 genes were differentially expressed in the RBFF, while 1766 were differentially expressed in RICF. Ten genes related to light stress were screened from the differentially expressed genes, and the reliability of transcriptome data was verified by qRT-PCR. The results of expression analysis of light response related genes showed that most of the genes under red-blue filter film were expressed in large quantities, and the expression reached peak at 15 d; under far infrared cut-off film, the expression of three genes was higher, while the expression of others was lower. The expression of most genes reached peak at 15-21 d. This study would provide a theoretical basis and data support for further exploring photoresponsive genes in the lettuce genome and revealing the molecular mechanism of the lettuce response to light.

  • Crop Pests, Diseases and Their Control, Environmental Protection
  • Crop Pests, Diseases and Their Control, Environmental Protection
    JING Yan,ZHOU Hui,LIU Xihui,TAN Fang,ZHANG Xiaoqiu,ZHANG Ronghua,SONG Xiupeng,LI Yangrui,YAN Meixin,LEI Jingchao,QIN Zhenqiang,LUO Yawei,LI Dongmei,WEI Jinju
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    The most effective way to control sugarcane smut is to plant resistant varieties. The evaluation of resistance to sugarcane smut is a very important procedure in the breeding of resistant varieties. In order to evaluate the resistance to smut of the eight new sugarcane clones bred by Sugarcane Research Institute of Guangxi Academy of Agricultural Sciences, the suspension of mixed Sporisorium scitamineum was inoculated to the new clones to obtain the incidence, also the natural incidences of smut in the field were investigated. The investigation period included new planting and first ratoon of sugarcane. ROC22 was used as the control. The results showed that GT12-765 and GT12-2262 were resistant to smut; the clones GT12-2476 and GT12-2004 were moderately resistant; GT12-162 was moderate susceptible; GT12-762, GT12-2425 and GT12-917 were susceptible to smut; and the CK (ROC22) was susceptible. The artificial inoculation could be used to more accurately evaluate the resistance to sugarcane smut, compared to the natural infection. The results of this study would provide a basis for breeding sugarcane varieties with high resistance to smut.

  • Crop Pests, Diseases and Their Control, Environmental Protection
    DUAN Yajie,MEI Zhigang,SUN Dequan,LI Weiming,PANG Zhencai,HU Huigang
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    The screening of antagonistic bacteria from soil microorganisms in the areas with banana Fusarium wilt is of great practical significance for controlling this disease. In this report, a strain, designated FS-4, was isolated from healthy banana rhizosphere soil in the area affected by Fusarium wilt. Based on Gause’s No. 1 synthetic medium, the optimization of medium, single factor experiments and response surface experiments were conducted to maximize the production of the antibacterial substances of actinomycete FS-4. The best fermentation medium and fermentation conditions were as follows: sucrose 2.4%, peptone 0.5%, K2HPO4 0.05%, NaCl 0.05%, MgSO4 0.05%, fermentation temperature 28 ℃, initial pH 7. Under the conditions, the inhibition zone diameter of actinomycete FS-4 fermentation filtrate reached 27.1 mm on the test plates of Bacillus subtilis after 62 h incubation

  • Crop Pests, Diseases and Their Control, Environmental Protection
    CHEN Min,ZHANG Jing,CHEN Lilang,YE Huochun,YAN Chao,FENG Gang
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    The insect growth inhibitor activity of allamdin was evaluated against Spodoptera litura (Fabricius) in the laboratory. The growth regulatory activity was found to be depended on the concentration of allamdin. Compared to the control larvae, the amount of food intake was reduced, the growth of larvae was inhibited, and the development of larvae was prolonged. The treated larvae molted to malformed pupae in the pupal stage and the moths after emergence exhibited morphological defect. A higher percentage of mortality at the prepupal and pupal stages was found and caused by moult disruption. The work shows that allamdin needs to be further studied as a lead compound for a novel potential insect control agent or for pests field population management.

  • Crop Pests, Diseases and Their Control, Environmental Protection
    GUO Lijia,WANG Jun,YANG Laying,LIANG Changcong,ZHOU You,LIU Lei,HUANG Junsheng
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    Bacillus strains, including Bacillus amyloliquefaciens, B. subtilis and B. thuringiensis, are important beneficial microbes, which have been applied for the biocontrol of plant diseases and pests. We isolated a Bacillus strain named JK05 previously, and it was identified as Bacillus amyloliquefaciens subsp. plantarum based on its morphological characterization, physiological, and biochemical properties as well as 16S rRNA and gyrA gene seqences analysis. The confrontation assay showed that JK05 had antifungal activities against a number of fungal phytopathogens. Plant growth promotion assay revealed that JK05 played roles in promoting plant growth of maize (Zea mays L.) and banana (Musa spp.). The pot assay demonstrated that JK05 possessed a prominent effect on the control of Fusarium wilt of banana caused by F. oxysporum f. sp. cubense. The PCR assay performed using the specific primers for genes related to the antibiotic biosynthesis revealed that the genome of JK05 contained the genes responsible for the synthesis of surfactin, fengycin and iturin A. The results suggested that JK05 had an excellent biocontrol potential, which could be applied as biopesticides and biofertilizers.

  • Crop Pests, Diseases and Their Control, Environmental Protection
    GUO Ying,LIN Zhikai,WANG Wenhua,LIU Liqing,HE Enming
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    Sugarcane variety ‘Badila’ which infected with Leifsonia xyli subsp. xyli (Lxx) was used as the materials in this research. The accumulation of Lxx in sugarcane stems was studied by real-time qPCR. And the pathological changes of vascular bundle of stems were studied by the semi-thin section technique. The results showed that the accumulation of Lxx decreased from the base layer to the tail layer in ‘Badila’. Severe damage to phloem and xylem in the vascular tissue of the base of sugarcane stems. The basal cells between the stem nodes were much smaller than those between the stems. The xylem was heteromorphism, the cell of xylem was different in size and arranged tightly. The damage of phloem and xylem in the vascular tissue of sugarcane stem infected with Lxx was positively correlated with the distribution of Lxx. It was speculated that the structure difference between the stem node and stem was one of the reasons why the quantity of Lxx decreased from the base layer to the tail layer. It would provide a theoretical basis for the further study of the interaction between bacterial of Lxx and sugarcane hosts.

  • Crop Pests, Diseases and Their Control, Environmental Protection
    AO Lisi,WANG Wei,REN Dongdong,LI Huijing,HUANG Jiaqi,JI Chunyan
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    A rapid nested-PCR detection system for Falcataria moluccana stem canker disease was established. The outer pair of primers EF-688F/986R and the inner pair of primers EF-AF/AR were designed based on the EF 1-α gene sequences of Lasiodiplodia theobromae. The established specific nested-PCR could amplified a single product of 264 bp with annealing temperature of 63 ℃, reaction cycles of 37. The lowest detectable concentration was 1 fg/μL. L. theobromae could be specifically detected by nested-PCR from the diseased plant samples. The establishment of rapid, sensitive nested-PCR detection system of L. theobromae might have significance in early diagnosis, and disease control of F. moluccana stem canker.

  • Agricultural Product Processing, Preservation, Storage, Analysis and Detection
  • Agricultural Product Processing, Preservation, Storage, Analysis and Detection
    CHEN Yunlan,LI Xueling,JIANG Kuaile,MO Lizhen,ZHOU Zhiwei,CHEN Zhihua,GUI Hua
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    Yunnan arabica coffee was used as the raw material. Pectinex Ultra SP-L pectinase was added in the wet fermentation process of coffee to remover pectin, and the physicochemical and sensory properties of the processed coffee beans were analyzed. The results show that pectinase could effectively and rapidly remove coffee pectin compared with the natural fermentation, and the pectin removing time was positively correlated with the concentration of pectinase, pectin removing temperature and maturity of fresh fruits. There was no significant difference in the contents of coffee beans obtained with pectinase and natural fermentation, and the cup quality was clean and stable. The cup quality of coffee beans treated by pectinase with low concentration of 0.01% was higher than that by natural fermentation, while that of the 1.00% and 0.10% pectinase treated was slightly lower than that of the natural fermentation.

  • Agricultural Product Processing, Preservation, Storage, Analysis and Detection
    LIU Xinting,YAN Ning,LI Wen,ZENG Jiaoke
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    In order to investigate the effect of spermidine on the texture and ripening of postharvest papaya fruit, the papaya fruit (cv. Risheng) was used as the test material. The changes of respiration rate and color of the spermidine treated papaya fruit during storage were determined, and various texture parameters of papaya fruit were determined by the texture profile analysis (TPA). Papaya fruit softening was delayed by appropriate concentration of spermidine, and the treatment of 5 mmol/L spermidine had the best effect, followed by 1 mmol/L spermidine, which resulted in higher hardness, chewiness, adhesiveness, significantly reduced the rate of fruit respiration, and delayed the fruit transformation. On the contrary, the treatment of 10 mmol/L spermidine accelerated the softening of papaya fruit. Correlation analysis indicated that there was significant positive correlation between fruit firmness, chewiness, adhesiveness, cohesiveness and recovery, but there was no obvious correlation between elasticity and other texture parameters (P<0.519). The results indicated that the TPA test could be used to evaluate the changes of postharvest papaya fruit texture.

  • Agricultural Product Processing, Preservation, Storage, Analysis and Detection
    LI Ying,LIU Xialei,LIN Yaxin,CHEN Xuemei
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    The extracting rate of the pectin was used as the analytical index, and the ultrasonic-microwave synergistic extraction of dried fruit peel pectin from passion fruit was optimized by the response surface methodology. The optimum process parameters of the ultrasonic-microwave synergistic extraction of the peel of passion fruit were obtained, namely liquid to material ratio 30 mL/g, pH 2.0, temperature 50 ℃, water bath 60 min, ultrasonic power 50 W, microwave power 600 W, ultrasonic-microwave time 8.0 min. Under the condition, the yield of pectin could reach (12.14±0.06)%. Compared with water extraction, ultrasonic and microwave methods, the extraction rate of ultrasonic-microwave synergy method increased by 47.33%, 34.74% and 23.50%, respectively. The esterification degree of the four extraction methods was≥50%, indicating that the peel pectin of passion fruit was a high methoxyl onein. The results of scanning electron microscopy showed that the cell wall of the fruit peel was broken more thoroughly under the synergistic effect of ultrasound-microwave, which was beneficial to the dissolution of pectin.

  • Ecology
  • Ecology
    ZHI Jiazeng,ZHOU Jinsong,DU Hao,LI Zongkai,WANG Chao,GAO Mei,ZHANG Guangyong,CHEN Weiqiang
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    Using the Levins and Shannon-Wiener niche breadth, Pianka niche overlap index, we researched the niche dynamics of the dominant weeds in the banana fields in the mountainous regions of Hekou to analyze the dynamic response characteristics on the niche of the dominant weeds in dry and rainy seasons, and to provide guidance for the ecological control of the weeds in the mountainous banana fields. The niche breadth and overlap of the weeds in rainy season and dry season had significant changes. Digitaria sanguinalis, Echinochloa colona, Cyperus rotundus had the widest niche breadth in rainy seasons, and Bidens pilosa, Conyza canadensis, Myosoton aquaticum had the widest niche breadth in dry seasons. The niche overlap among weeds was generally large, the value more than 0.50 for the two seasons accounted for 66.7% and 44.4% respectively. The similarity ratio was high, and the mean value was 0.54 and 0.40 correspondingly for the two seasons. It indicated that there was no obvious single dominant species, there was a high competition or complementarity in the utilization of resources among weeds. The weeds with larger niche breadth and overlap value will intensify the competition and exclude other weeds in the process of community succession under the condition of insufficient resource allocation.

  • Ecology
    HUANG Xuguang,QIN Ling,HUANG Lidan,LU Yansong,LUO Enbo,HUANG Lingpu,LIU Yuefei
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    A pot experiment using a cultivar ‘Purple Peony’ as the experimental material was conducted under drought and rehydration condition. The effects of drought at seedling stage and rehydration on the physiological characteristics of roots and the soil microbial diversity in the rhizoshere were studied. The total root length, root surface area and root tip numbers were significantly decreased in the drought and rehydration treatment (T2), compared to the normal condition (CK), but they were significantly increased compared with the drought stress without rehydration (T1). Under drought stress (T1), Algiphilus, Aureispira, Chloronema, Acrospermum were the special bacteria. Anaerolineaceae, Acidobacteria, Acidimicrobiales, Sphaerobacter and Streptomyces were the dominant bacteria in the rhizoshpres of all drought and normal treatments. Sordariale, Eurotiales, Pseudallescheria, Pleosporales and Cladosporium were the dominant fungi. Goniomonas, Lamprospora and Sorodiplophrys were the special fungi in drought stress (T1) and rehydration after drought stress (T2). Bacteria such as Acidimicrobium, Anaerolineaceae, Algiphilus, Pseudallescheria, Cladosporium, having certain biocontrol effects, could be reasonably used in agricultural production, which could contribute to the resistance of plants to drought stress and the improvement of water use of Hibiscus under drought stress.

  • Ecology
    WANG Ru,LIU Xianglin,ZHOU Zhiqiang,LI Yunyun,CHEN Yanhui,CHEN Jin,WANG Guo
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    In order to investigate the effect of ammonium chloride (NH4Cl) and tea saponin (TS) on cadmium speciations in soil, the Cd-contaminated agricultural soils around mining areas were used as the experimental material. The effects of different doses of NH4Cl, TS and mixed application on the physical chemical properties of the Cd polluted agricultural soil and Cd availability were simulated. The chemical of cadmium speciations was transformed from residual fractions into acid extractable or oxidizable fractions by adding NH4Cl or TS singly. NH4Cl obviously improved available Cd in soil, and high (60 mg/kg) concentration of NH4Cl was better than low (20 mg/kg). Moreover, the chemical cadmium speciations was transformed from residual fractions into acid extractable fractions and improved available Cd by adding the combination of NH4Cl (40 mg/kg) and TS (4 mg/kg), and mixed application had the same effect with NH4Cl or TS. Stepwise regression analysis showed that pH and Cl -were the two key factors affecting Cd availability in soil. In the actual phytoremediation work, in order to increase the Cd content of plants, we could take appropriate agronomic measures to increase Cl - or decrease pH in soil. Low concentration NH4Cl and TS mixed application significantly would improve the Cd bioavailability and avoid soil environment destruction caused by high concentration NH4Cl application.