Current issue

• 2018 Vol.34 No.30 Published:31 October 2018

  Suitable Sowing Date for Rice Under Controlled Irrigation by Using ORYZA v3 Model 2018, 34 (30):  1-6.  DOI: 10.11924/j.issn.1000-6850.casb17070074 Abstract + ( 686 )   To develop non-flooding controlled irrigation in accordance with local conditions and minimize the yield loss caused by unreasonable cultivation measures, it is necessary to investigate the suitable sowing date for rice. In this text, ORYZA v3 model was firstly calibrated and validated based on data collected from non-flooding controlled irrigation rice field experiment in Kunshan, Jiangsu province, before it was used to simulate the growth of the rice under different climatic conditions from 1971 to 2010 (40 years). According to the model output value of DVS, the rice season period length, yield and some relevant rice growth factors were analyzed, and finally figure out the optimum sowing date. The RMSEn value for model calibration and validation was fell in the range of 9%-26%, and the determination coefficient R2 was between 0.85 and 0.99, which show good performance of ORYZA v3 model. According to the value of DVS, the earliest and latest available sowing date for the non-flooding controlled irrigation rice is determined to be March 28th and June 13th. To acquire the maximum yield, the sowing date was chosen from May 23rd to June 13th. Meanwhile, considering the instability of the model simulation output, the maturity rate of rice, yield uncertainty and procreation stage length corresponding to difference sowing date, the most suitable sowing date for the non-flooding controlled irrigation rice in southern Jiangsu province was recommended as from on May 23rd to June 3rd.

  Tillage Methods: Effects on Photosynthetic Characteristics, Dry Matter Accumulation and Quality of Wheat 乔玉强,杜世州,李玮,陈欢 and 曹承富 2018, 34 (30):  7-11.  DOI: 10.11924/j.issn.1000-6850.casb17070081 Abstract + ( 658 )   To know the best wheat tillage method in no irrigation and Shajiang black soil condition, a field positioning test is used under five tillage treatments, including straw returned conventional and repression (PCR), no straw returned deep scarification and repression (ASR), no straw returned rotary tillage and repression (ARR), no straw returned rotary tillage (AR), no straw returned compound drill (ACP). The results showed that the highestPn andTr were found in ARR treatment with 26.54 μmol/(m2·s) and 10.53 μmol/(m2·s), 11.17 mmol/(m2·s) and 3.84 mmol/(m2·s) in wheat flowering and 20 days after flowering. TheSPAD of ARR was in the second place among different tillage treatments in 10 days after flowering. ARR treatment had the highest protein content, wet gluten content, sedimentation value and hardness. Therefore, ARR treatment is recommended as the most appropriate tillage treatment for promoting photosynthetic characteristics, dry matter and filling rate of wheat in Huaibei area of Anhui Province, and plays a positive role in achieving high yield.

  Effects of Water-nitrogen Coupling on Photosynthetic Characteristics, Yield and Water and Nitrogen Use Efficiency of Winter Wheat Under Drip Irrigation 2018, 34 (30):  12-19.  DOI: 10.11924/j.issn.1000-6850.casb17080004 Abstract + ( 651 )   The aim is to clarify the effect of water-nitrogen coupling on photosynthetic characteristics and yield of super-high yield winter wheat under drip irrigation. Split plot design was employed in this study. There were three treatments of drip irrigation levels: W1 (2775 m3/hm2), W2 (3900 m3/hm2) and W3 (4350 m3/hm2) and three nitrogen application amounts: N0 (0), N1 (180 kg/hm2) and N2 (270 kg/hm2). The effects of these treatments on chlorophyll and proteins contents of flag leaf, net photosynthetic rate, water use efficiency and yield of ‘Xindong41’were studied. The results showed that the effect of water-nitrogen simultaneous increase was better than that of only water increase or only nitrogen increase on chlorophyll contents and soluble protein contents, photosynthetic rate of the flag leaves, water use efficiency and yield. The chlorophyll contents of the flag leaves (increased by 44.5%, 41.2% compared with W1N0), soluble protein contents (increased by 20.8%, 16.85% compared with W1N0), photosynthetic rate (increased by 46.4%, 54.5% compared with W1N0), water use efficiency (increased by 31.9%, 34.7% compared with W1N0) and yield (increased by 19.05%, 20.86% compared with W1N0) after flowering were higher with W2N2 and W3N2 treatments. The important reason of higher yield with W2N2 and W3N2 treatments was the greatly improved photosynthetic performance of the flag leaves. Taken together, W2N2 (3900 m3/hm2, 270 kg/hm2) was the optimal water and nitrogen model which gained nearly 9000.0 kg/hm2 wheat yield.

  Soybean Grain Detection Method Based on MATLAB Image Processing 2018, 34 (30):  20-25.  DOI: 10.11924/j.issn.1000-6850.casb17100005 Abstract + ( 1157 )   To solve the problems of low accuracy of human counting and time consuming of photoelectric counting and so on in laboratory test of single soybean plant, the computer vision system and the MATLAB software development platform were used in single plant test instead of human counting in laboratory test of single soybean plant. The algorithm used the spatial filtering of the soybean grain image to remove the noise, and the "Otsu" method optimized the global threshold segmentation of the image. Based on the image processing, the two factors, the number of grain and the size of grain, were measured. Two indexes, soybean grain counting and soybean grain size grading, were studied with six soybean varieties as materials, namely ‘Zhouhei soybean’,‘Zhouqing soybean’,‘Zhoudou 11’,‘Zhoudou 18’,‘Zhoudou 22’and‘Zhoudou 23’. The experimental results showed that the algorithm and the procedure were accurate and effective, and the grain number of single soybean could be calculated accurately. The algorithm and procedure determined that the average area of the soybean grain in each variety was positively correlated with the 100 grain weight, and the coefficient of determination was 0.987. So the algorithm and procedure can determine the size of soybean grain accurately and effectively. In short, the method of soybean grain detection based on MATLAB image processing can reduce the human labor intensity and human visual deficiencies relatively, and it is of certain significance in improving work efficiency and accuracy.

  Genetic Diversity Analysis of 130 Accessions Beta vulgaris Germplasms with Phenotype and Molecular Marker 2018, 34 (30):  26-36.  DOI: 10.11924/j.issn.1000-6850.casb18050020 Abstract + ( 738 )   The aim is to study the genetic diversity and genetic distances of sugar beet germplasms. Phenotype and molecular markers were combined to analyze the genetic diversity of 130 accessions B. vulgaris germplasms from three aspects, and the genetic distances were also analyzed. 130 accessions B. vulgaris germplasms showed more abundant genetic diversity. The Shannon- wiener indexes of 22 descriptive characters were between 0.0451 and 1.1867 with an average of 0.8559. The coefficients of variation (CV ) of 23 numerical characters were from 2.94% to 594.84% with an average of 59.10%. The polymorphism information contents (PIC ) of 34 SSR markers were 0.1289-0.7847 with an average of 0.4887. Morphological markers and molecular markers were combined to calculate genetic distances, and these 130 germplasms were divided into five related groups. Sugar yield, brix of root and root rot disease index exhibited significant differences between all adjacent groups. These results suggest that the analyzed B. vulgaris germplasms have abundant genetic diversity, the genetic distance analysis has biological significance and can be the reference for germplasm innovation.

  Studies on Correlated Characters of Monosomic Addition Lines of Sugar Beet and Aerial Experiment Material 2018, 34 (30):  37-41.  DOI: 10.11924/j.issn.1000-6850.casb17100053 Abstract + ( 641 )   To undersdand genetics mechanism of high frequence transfer of monosomic addition line M14, charecters of monosomic addition lines and aerial axperiment materials of beet were analyzed by means of ovule separation, pollen abortion investigation and sugar content detection method. The results showed that the facultative apomixis phenomenon was exist in monosomic addition line M14. The ratio of apomixis was 96.5%, and pollen abortion was above 90%. Blastocyst was formed through megasporocyte mitosis and sperm-egg binding was not needed for breed offspring. The ratio of zoogamy was 3.5% and sexual reproduction plants maybe exist a lethal gene. The results also showed that sugar contents of monosomic addition lines and aerial axperiment materials were higher than that of cultivated beets. The exclusive genetics charecters of distant hybridization and aerial axperiment materials of sugar beet were determined by the beta corolliflora chromosome carried with high sugar content, disease resistance as well as apomixis genes. These results will be useful for exploiting beta corolliflora beneficial genes on chromosome engineering.

  Soil Microorganisms and the Mechanism of Potato Continuous Cropping Obstacle: Research Progress 2018, 34 (30):  42-45.  DOI: 10.11924/j.issn.1000-6850.casb17110026 Abstract + ( 634 )   Continuous cropping can lead to a decline of potato yield and quality, and has become a prominent problem in the potato industry development in China. We summarized the mechanism of continuous cropping obstacle of potato from the aspects of soil nutrient loss, soil enzyme activity change, plant allelopathy and microecological imbalance. Then, we figured out that the main reason for potato continuous cropping obstacle was the function imbalance of root soil microecology. Finally, we put forward the countermeasures targeting the continuous cropping obstacles in potato planting from the perspective of multi-factor interaction, and discussed the research prospect.

  Multi-cropping and High Efficient Planting Patterns of Potato in Northeastern Dryland of Sichuan: Benefit Analysis 2018, 34 (30):  46-51.  DOI: 10.11924/j.issn.1000-6850.casb17080030 Abstract + ( 646 )   The paper aims to enrich the multi-cropping and high efficient planting patterns and improve planting efficiency of potato in northeastern dryland of Sichuan, two new planting patterns “spring potato/maize/sweet potato” and “wheat+winter potato/maize/sweet potato” with traditional planting pattern “wheat/maize/sweet potato” as control were conducted to observe the annual unprocessed food grain yield and economic benefits. The results indicated that: there was no significant difference in unprocessed food grain yield between “spring potato/maize/sweet potato” and control, while the total output value and net benefits were significantly higher than control, by 52.16% and 53.25%, respectively. Moreover, the net labor productivity of “spring potato/maize/sweet potato” was 14.85% higher than control. The unprocessed food grain yield and total output value of “wheat+winter potato/maize/sweet potato” were significant higher than that of control, while the net benefits and net labor productivity were 20.32% and 17.07% lower than control. The rate of return of material cost and cost benefit ratio of both new planting patterns were lower than control. Comprehensive comparison, “spring potato/maize/sweet potato” could be used as the alternative pattern for popularization and application.

  Identification of Main Potato Varieties in Shanxi with Peroxidase Isozyme 2018, 34 (30):  52-55.  DOI: 10.11924/j.issn.1000-6850.casb17080067 Abstract + ( 532 )   In order to identify the potato varieties, we used polyacrylamide gel electrophoresis to separate the peroxidase isozyme of the potato, and identify the potato varieties with the enzyme band map. With 14 different varieties of potato buds, stems and leaves as experimental material. Respectively to extract peroxidase isozyme of the different parts of the experimental materials for polyacrylamide gel electrophoresis. Analysis of isoenzyme zymogram differences, to determine the differences between the varieties and genetic relationship. The results showed that the peroxidase isozyme of buds could be used as a criterion to distinguish the potato varieties. In 14 different varieties, No.4 and No.7 enzymatic bands were similar, they were Jinshu 14 and Jinshu 11; No.6 and No.9 enzymatic bands were similar, they were Jinshu 21 and Jinshu 18; No.5 and No.12 enzymatic bands were similar, they were Tongshu 22 and Tongshu 20; No.13 and No.14 enzymatic bands were similar, they were 05-32-7 and Tongshu 23. It indicated that the genetic relationships between these cultivars were relatively close.

  Research Progress of Molecular Biology of Arabidopsis thaliana 2018, 34 (30):  56-62.  DOI: 10.11924/j.issn.1000-6850.casb18050095 Abstract + ( 743 )   Arabidopsis thaliana plays a reference role in plant science research. This research retrieved molecular biology papers from NCBI and Web of Science, and analyzed these papers with Noteexpress software. 1865 papers related to molecular biology ofArabidopsis thaliana published since October 2016 to September 2017 were collected, including 779 papers which had the impact factor above 5.0. The most important developments were reviewed from four aspects, metabolism, light and temperature, stress resistance, growth and development, which could provide guidance to the related research of other plants.

  Cloning and Expression of psy Gene from Rhododendron molle 2018, 34 (30):  63-70.  DOI: 10.11924/j.issn.1000-6850.casb17070067 Abstract + ( 558 )   We aim to study the function of psy gene and its molecular mechanism in petal coloring. A psy gene was cloned from the Rhododendron molle cDNA by using RT-PCR and RACE methods. The full length of the psy gene was 1638 bp, named RmPSY (GenBank accession No. KX230461), which contained a 1296 bp open reading frame encoding 432 amino acid residues. RmPSY, a hydrophilic unstable protein with no signal peptide, was a non-secreted protein. The putative protein molecular weight was 48.91 kD and its theoretical isoelectric point was 8.78. Homologous alignment showed that it shared 81% amino acid identities with PSY from other plants in GenBank. The phylogenetic tree constructed on the basis of amino acid sequences of PSY suggested that the relationship between R. molle and Vitis vinifera was the most intimate. The results showed that the RmPSY gene was expressed in the petal during the flower development. The RmPSY transcripts were the most abundant in the initial opening period of flower, low in the bud stage, and decreased during the blooming period of flower. This study may provide references for further research on the molecular mechanism of RmPSY involved in the formation of R. molle flower color.

  Bx-Daf-22 in Bursaphelenchus xylophilus (Aphelenchida: Aphelenchoididae): Cloning and Expression 2018, 34 (30):  71-75.  DOI: 10.11924/j.issn.1000-6850.casb18040093 Abstract + ( 688 )   To explore the molecular mechanism ofBursaphelenchus xylophilus dauer larvae 3 formation, the cGMP pathway geneBx-Daf-22 was identified. Based on theB. xylophilus genome, a SCP2 homologous gene was identified by BLAST, and named asBx-Daf-22 .Bx-Daf-22 was cloned by the method of PCR. And some bioinformatics analysis, such as phylogenetic and conserved domain analysis were conducted based on the amino acid sequence of Bx-Daf-22. Then, the orthologous alignment and 3D structure of the Bx-Daf-22 were constructed. The expression levels ofBx-Daf-22 in different larvae and adults were tasted by Q-PCR. The results indicated that: the Bx-Daf-22 consisted of 4α helices, 1 310 helix at the C-terminal, and 5β -pleated sheets among the middle of theα helix. Compared with the expression level in L2, the expression of DL3 were significantly up- regulated, the expression of Bx- Daf- 22 in male adult was significantly suppressed. The structure of Bx-Daf-22 and the expression ofBx-Daf-22 indicate that the gene is involved in cGMP pathway and directly related to DL3 formation.

  Comparison of SSR and InDel Markers Amplified with Three Kinds of PCR Programs in Sugar Beet 2018, 34 (30):  76-80.  DOI: 10.11924/j.issn.1000-6850.casb18040116 Abstract + ( 800 )   To amplify the SSR/InDel labeled products with clear and less nonspecific bands, twelve different genotype beet cultivars from six countries were selected. The products were amplified using SSR markers, InDel markers and three PCR procedures, including touch-down PCR, gradient PCR, and conventional fixed annealing temperature PCR. By comparing the polymorphism, stability, and clarity of the amplification product, a PCR reaction program suitable for both molecular markers was selected. The results show that the touch- down PCR method can successfully amplify the sample products with clear bands and stable amplification effect, without invalid product through a single reaction. Gradient PCR amplification results are unstable, there are non-specific bands and diffuse phenomenon is serious. The fixed annealing temperature PCR has different amplification results due to different primers, and accompanied by diffusion phenomenon. The specificity and stability of touch-down PCR amplification products are higher than that of gradient PCR and fixed annealing temperature PCR, meanwhile the process of groping the optimal annealing temperature is omitted compared with gradient PCR method. Therefore, touch- down PCR procedure is recommended for sugar beet SSR and InDel molecular markers

  Numerical Wind Tunnel Simulation of Psammophyte Seed Wind Dispersal Along Railway Lines 2018, 34 (30):  81-89.  DOI: 10.11924/j.issn.1000-6850.casb18040086 Abstract + ( 549 )   To study the ecological adaptation strategy of the seed wind dispersal mechanism of psammophyte along railway lines, 5 Artemisia species along railway lines in sand dune areas in northwestern Liaoning Province were studied. With the aid of the fluid dynamics equation and computer graphics technology, the numerical wind tunnel was used to simulate and forecast the variation trend of seed dispersal time and dispersal distance at different wind speed and seed releasing heights. The results of software simulation showed that: (1) at the same seed releasing heights and the same wind speed, the flight time and flight distance of 5 Artemisia species showed the opposite trend with seed weight, the horizontal flight time and flight distance were shortened while the seed weight increased; (2) at the same seed releasing heights and the different wind speed, the flight time and flight distance of 5Artemisia species showed the same trend with wind speed, the flight time and flight distance increased while the wind speed increased; (3) at the same wind speed and the different seed releasing heights, the flight time and flight distance of 5Artemisia species showed the same trend with seed releasing heights, the flight time and flight distance increased while the seed releasing heights increased. Seed weight, wind speed and seed releasing heights are sensitive factors that influence seed dispersal time and dispersal distance, and should be taken into consideration in the selection of suitable plant sand-control in the sandy area along railway lines for ecological restoration.

  Effect of Returning Straw on Transfer and Accumulation of Cd in Soil-rice System: Research Progress 2018, 34 (30):  90-95.  DOI: 10.11924/j.issn.1000-6850.casb17080032 Abstract + ( 618 )   China is a big agriculture country for rice planting, and produces large quantities of straw annually, which could be used in resource recycling. Returning into soil directly is a common approach of straw resource recycling and a way to reduce the straw- burning effectively. However, with the pollution of heavy metal cadmium (Cd) in paddy soil increasingly, the degree of straw contaminated by Cd is also increased, which leads to the accumulation of Cd in rice straw, so returning straw to soil directly could bring Cd accumulated in rice straw back to soil again. On the other hand, there are many active organic matters produced during the progress of decomposition of straw, which have complicated effects on the activity of Cd in soil-plant system. It deserves further study on the effect of straw returning on transfer and accumulation of Cd in soil-plant system. The authors introduced Cd pollution in rice straw at present, especially summarized the influences on soil physical and chemical properties such as soil organic matter, pH value and the available content of Cd after straw returning. Returning straw back to soil could increase yield and also the risk of Cd enrichment. Finally, the article pointed out some practical problems for considering, and discussed the prospect of safe utilization of

  Effects of Iron-based Compound Soil Conditioner on Cd Absorption and Accumulation in Rice from Three Kinds of Cd Polluted Soils 2018, 34 (30):  96-100.  DOI: 10.11924/j.issn.1000-6850.casb17080016 Abstract + ( 486 )   To study the effect of iron-based compound soil conditioner on soil pH value, soil available Cd content, and yield and Cd content of rice in different polluted soil types, the mechanism of iron- based compound soil conditioner to reduce soil Cd bioavailability was discussed. In this paper, acid, weak acid and neutral Cd polluted soil were selected, with 2250 kg/hm2 application rate of iron- based compound soil conditioner for field plot test. The results showed that the iron-based compound soil conditioner could increase soil pH value, reduced soil available Cd content and the bioavailability coefficient of Cd. The iron-based compound soil conditioner had the best Cd reducing effect on the neutral paddy soil in Zhuzhou. The soil conditioner could also improve the yield of brown rice and reduce Cd content in brown rice. The content of Cd in brown rice of Zhuzhou and Xiangtan reached the national food hygiene standard. The results could provide a theoretical basis and data support for the treatment of cadmium contaminated soil and safe production of rice.

  Heat Damage on Single-cropping Rice in Nanchong: Occurrence Regularity and Its Effects on Yield 黄维,,刘永裕 and 吴炫柯 2018, 34 (30):  101-109.  DOI: 10.11924/j.issn.1000-6850.casb17070069 Abstract + ( 557 )   Heat damage is one of the major agricultural meteorological disasters affecting rice production in Nanchong. By studying the occurrence regularity of heat damage and its relationship with the fluctation of rice yield, it could provide a reference for stabilizing rice yield and ensuring the normal production of rice in Nanchong. Based on the data during 1960-2014 from 7 meteorological stations in Nanchong, the authors analyzed the temporal and spatial distribution of heat damage; meanwhile, we combined with rice yield from 1981 to 2014 in Gaoping and the authors analyzed the influence of heat damage on rice yield with the wavelet analysis. The results showed that: heat damage showed mostly mild degree, followed by moderate degree, and then was severe degree in Nanchong; the occurrence frequency of total heat damage showed a firstly decreased and then increased trend; there was lower occurrence frequency of heat damage in 1980s; there was more heat damage in the south than in the north; there was a significant reverse resonance period of 3-4 a between relative meteorological yield and heat damage after 2000. Heat damage becomes a major agricultural meteorological disaster which influences rice yield fluctuation in Nanchong after 2000. The results of the study could provide a basis for relevant departments to formulate rational production layout and defensive measures for heat damage.

  National Observation Stations and Automatic Weather Stations in Vineyard Area at the East Foot of Helan Mountain: Comparative Analysis of the Minimum Temperature 2018, 34 (30):  110-117.  DOI: 10.11924/j.issn.1000-6850.casb18030104 Abstract + ( 1027 )   The paper aims to promote the development of grape industry in Ningxia, enhance the meteorological service ability for grape production, and provide support for future lattice forecast and professional forecast services. Based on the hourly minimum temperature data of 27 automatic weather stations and 7 national observation stations of vineyard area at the east foot of Helan Mountain from April to May during 2009-2016, we compared and analyzed the differences of the minimum temperature between the automatic weather stations which were represented the chateau and the national observation stations in the area (abbreviation: Dajian Station). The results showed that the minimum temperature appearing at the east foot of Helan Mountain was from 20:00 to 10:00, with the majority in 03:00 to 08:00, and the occurrences at 07:00 were the most. According to historical data analysis and the comparison of actual cases, there was a significant difference between the minimum temperature of chateau station and national observation station, and the difference was generally within 3℃.

  Spatial-temporal Change of Consecutive Dry Days in Changtang National Nature Reserve of Tibet During 1971-2017 2018, 34 (30):  118-122.  DOI: 10.11924/j.issn.1000-6850.casb18050139 Abstract + ( 696 )   The paper aims to comprehensively analyze the drought characteristics of Chang Tang national nature reserve region of Tibet during 1971-2017 and effectively response to drought risk and ecological environmental protection. The authors obtained the spatial-temporal drought distribution characteristics of Chang Tang national nature reserve region by using daily precipitation data of 5 meteorological stations from 1971 to 2017 with drought evaluation indicator as the Consecutive Dry Days (CDD) and statistical methods like linear regression, Mann-Kendall test and rescaled range analysis (R/S analysis) et al. The results shows that: On a multi-year average, the CDD ofSeachSstation were 78-162 days in nature reserve region, and the distribution was decreasing from eastern to western, as well as the probability of more CDD was 51.1%. The CDD exhibited decreasing trend with a rate of 3.4 d/10a in nature reserve region during the recent 47 years, and it increasing trend since the 1990s. On the decadal scale, the CDD was more in the 1970s and normal during 1980s to 2100s, in addition the CDD was the highest in the 1970s during the past 47 years. Also, the CDD were more anomalous years in the 1990s with a frequency of 2 times, whereas less anomalous years not occurred. According to the Mann-Kendall test, the abrupt change of CDD occurred in 1980, indicating a change from the more period to the less one. The results of R/S analysis showed that changes of CDD had the persistence with a Hurst index of larger than 0.5 in nature reserve, which indicates that it will assume continuous decrease in future.

  Preparation and Identification of Cronobacter sakazakii Polyclonal Antibody 2018, 34 (30):  123-128.  DOI: 10.11924/j.issn.1000-6850.casb17090123 Abstract + ( 602 )   To obtain high titerCronobacter sakazakii antibody,C. sakazakii polyclonal antibody was prepared in rabbits using formalin- inactivated C. sakazakii and C. sakazakii cell debris as antigen. The titers of antiserum were 256000 and 64000, respectively, and formalin-inactivatedC.sakazakii antigen was chosen to prepare the antibody. Antibody was purified by octanoic acid-ammonium sulfate precipitation method, the purity of the pAb was detected by SDS- PAGE. The antibody had no cross reaction with S.aureus , L. monocytogenes ,S.typhimurium ,S.flexneri andE.coli by dot blot hybridization method butsalmonella . To get rid of the disturb ofsalmonella , the purified pAb was dealt withsalmonella bacterial antigens with reverse adsorption method to eliminate the cross reaction withsalmonella . The high-titer pAb special toC.sakazakii could be obtained by formalin-inactivated antigen and purified by reverse adsorption method and it was a good foundation for immune detection method development.

  Quantitative Determination of Anthocyanins from Purple and Black Crops 2018, 34 (30):  129-135.  DOI: 10.11924/j.issn.1000-6850.casb18030048 Abstract + ( 609 )   To find a rapid and economic method for the determination of total anthocyanins from purple and black crops in nature, the anthocyanins were extracted from three different crops of black wheat, eggplant and grape by using acidic ethanol. The total anthocyanin content from the three samples was determined by retentate analysis with pH differential method and subtraction method. The results showed that there was no significant difference in the accuracy of the results between the two methods using for black wheat and grapes. It was found that the absolute value of the difference between the results of the two methods was less than the uncertainty of quality determination when the two kinds of samples were re- tested, indicating that pH differential method and subtraction method were both applicable to laboratory quantitative detection of anthocyanin from black wheat and grapes. The relative standard deviation of eggplant measured by pH differential method was 2.20%, the precision was better than that of the subtractive method. There was a case of 4 consecutive points rise for the eggplant anthocyanins detected value from the quality control chart, showing that the accuracy of eggplant peel anthocyanin test results was poor by using subtraction method. The retesting showed that the absolute value of the difference between the two results obtained by the subtraction method was 0.023 mg/g, which was higher than the uncertainty of the measurement result 0.011 mg/g, indicating that the test results of anthocyanin from eggplant by pH differential method were reliable, but the test results by subtraction method had some problems.

  Potato Late Blight in Sichuan: Research Progress 2018, 34 (30):  136-139.  DOI: 10.11924/j.issn.1000-6850.casb18060041 Abstract + ( 703 )   The potato late blight, caused by Phytophtora infestans, has become the disastrous disease of potato. Sichuan province is one of the major potato production areas in China, and it is also a major disaster area for potato late blight. This paper summarizes occurrence characteristics, pathogens, surveillance Techniques and prevention methods of potato late blight in Sichuan province. It points out that the change of P.infestans population and the results of suitable potato varieties for different ecological regions. It is necessary to strengthen the research on disease resistant varieties and monitoring and early-warning technology based on big data analysis, which will be the focus of future research and major measures of control preparation.

  Mixing of Herbicides by Spraying on Stems and Leaves of Flax: Effects for Controlling Weeds in Flax Field and Large Area Application 2018, 34 (30):  140-147.  DOI: 10.11924/j.issn.1000-6850.casb17080101 Abstract + ( 764 )   To control broadleaf weeds and grass weeds in flax field by spraying at one time, the authors carried out application test on 3 new types of broadleaf weeds herbicides including 40% MCPA- sodium and bromoxynil octanoate EC and 7 kinds of grass weeds herbicides including haloxyfop-P to control weeds in flax field by spraying on stems and leaves of flax seedling. The results showed that: 40% MCPA- sodium and bromoxynil octanoate EC 1500 mL/hm2 or 30% bromoxynil octanoate EC 1500 mL/hm2 mixed with 7 kinds of grass weeds herbicides including 108 g/L haloxyfop- P EC 1500 mL/hm2 had excellent control effects on broadleaf weeds in flax field, the plant and fresh weight control effects were between 94.17%-98.71%. 40% MCPA-sodium and bromoxynil octanoate EC 1500 mL/hm2 or 30% bromoxynil octanoate EC 1500 mL/hm2, 80% bromoxynil SP 600 g/hm2 mixed with 108 g/L haloxyfop-P EC 1500 mL//hm2 or 10% quizalofop-ethyl EC 900 mL/hm2, 50 g/L pinoxaden EC 1350 mL/hm2, 15% clodinafop-propargyl WP 750 g/hm2 had excellent control effects on grass weeds in flax field, the plant and fresh weight control effects were between 97.22%- 100%. Comprehensive evaluation from safety on flax, control effect, herbicides cost and yield effect, 40% MCPA-sodium and bromoxynil octanoate EC 1500 mL/hm2 or 30% bromoxynil octanoate EC 1500 mL/hm2 + 108 g/L haloxyfop-P EC 1500 mL/hm2 or 10% quizalofop-ethyl EC 900 mL/hm2 are the best combination for controlling broadleaf weeds and grass weeds in flax field by spraying on stems and leaves of flax at one time, which should be popularized and applied in flax production.

  The Rural Tourism Development Mode in China and Its Influencing Factors 2018, 34 (30):  148-152.  DOI: 10.11924/j.issn.1000-6850.casb17110040 Abstract + ( 585 )   The rural tourism is a new attempt to extend modern tourism to traditional agriculture. Since the beginning of the 21st century, the rapid development of rural tourism practice has provided a large number of research cases for domestic scholars. It is urgent to summarize the researches and put forward the representative development model, to better guide the practice. From the concept of rural tourism, the essentials of rural tourism include the core connotation of spatial attribute, subjective attribute and resource (product) attributes. Based on that, the discussion and summary of the rural tourism development model and its influencing factors should also focus on the core influencing factors such as the development subject and the development stage of rural tourism, the geographical location of rural areas nd natural and cultural attributes, and should dynamically consider the role of each factor and their interrelationships. Results showed that: different rural tourism destinations have different locations, resource endowment, policy environment and the development stages, and there are also great differences in rural tourism development model. Rural tourism development model could not be judged as good or bad, only be suitable for or not. The model should adapt to local conditions and circumstances, and cannot be applied mechanically.

  Influencing Factors of Farmers’Behavior of Agroforestry Based on Probit-ISM Model 2018, 34 (30):  153-159.  DOI: 10.11924/j.issn.1000-6850.casb18040031 Abstract + ( 626 )   Based on the survey data of 302 households from 27 villages in northern part of Jiangsu Province, using the Probit-ISM model to explore the influencing factors on farmers’ behavior of agroforestry and their relevance and hierarchies. The results indicated that the age and gender of householders, the household population and the understanding of relevant policy were significantly at the level of 5%; educational levels, annual income, woodland area, participating in farmer cooperatives or not, having agricultural technology promotion stations or not and the willing to loan were significantly at the level of 1%. Among these, annual income, having agricultural technology promotion stations or not and the willing to loan are the surface direct factors; woodland area and the understanding of relevant policy are the intermediate indirect factors; household population, educational levels and participating in farmer cooperatives or not are the deep roots of factors.

  Ozone: Purification Effect and Mechanism on Suspended Particulates in Circulating Water System 2018, 34 (30):  160-164.  DOI: 10.11924/j.issn.1000-6850.casb18040095 Abstract + ( 562 )   To study the purification effect and the mechanism of ozone on suspended particulates in water, discuss its application and process integration in aquaculture water treatment, the authors built several smallscale test systems, added different amounts of ozone into aquaculture water, analyzed the effect on TSS and turbidity, and conducted the grading analysis of particle size of suspended particulates. The control group did not add ozone, and the ozone adding amount of the 3 test groups was 30.1, 60.2, 90.3 mg, respectively, the treated water volume were all 4 L. The results showed that: (1) adding ozone could remarkably reduce the turbidity of aquaculture water; the turbidity of the 3 test groups was reduced by 12.47%, 25.31% and 30.20% respectively when the turbidity of initial water was (5.22 ± 0.55) NTU; (2) adding ozone was helpful for coagulation of suspended particulates in water body; the particle size of the suspension particulates in control group was mostly distributed in 48-68 μm; however, the rate of the suspended particulates whose particle size was above the 64 μm was 99.22% in test group water with the ozone adding amount of 90.3 mg, which contributed to subsequent physical filtration. The study suggests that the effect of ozone purification on suspended particulates is achieved by changing particle size distribution by the way of oxidizing organic compounds to produce complex precipitates and colloidal flocs, which provides theoretical support for the application of ozone in circulating water system.