Current issue

• 2019 Vol.35 No.9 Published:26 March 2019

  Yield of Various Hybrid Rice Cultivars: Responses to High Temperature During Heading Period 2019, 35 (9):  1-6.  DOI: 10.11924/j.issn.1000-6850.casb17110071 Abstract + ( 758 )   PDF ( 1233KB )   ( 380 ) To detect cultivation techniques of high and stable yield of rice and breeding new cultivars with resistance to high temperature under global warming condition, a field experiment is conducted to study the effects of high temperature during heading period on yield of 13 hybrid rice cultivars. The results showed that rice yield was significantly reduced by high temperature during heading period, the yield declined by 15.3% for each 1°C increase in this period. There were significant differences in response of yield of different hybrid rice cultivars to high temperature during heading period. The combinations of male parent Fengxinzhan had low seed setting rate (40.5%-59.3%), which had poorer tolerance to high temperature during this period. On the contrary, the combinations of male parent GR560 had greater tolerance to high temperature during heading period with high seed setting rate (64.9%-75.6%). To solve the problem of high temperature stress in rice heading period, more attention should be paid to breeding new cultivars with growth period suitable for the local cultivation environment, or adjusting cropping system and rice improving cultivation technique to ensure the crop to avoid high temperature during heading period.

  ‘Shangmai 156’: Effects of Wide-narrow Row Planting and Seeding Rate on Growth and Yield 倪雪峰,闫向泉,朱伟,孟自力 and 谢红梅 2019, 35 (9):  7-11.  DOI: 10.11924/j.issn.1000-6850.casb18100103 Abstract + ( 567 )   PDF ( 1190KB )   ( 347 ) ‘Shangmai’156 is a new wheat variety selected and bred by Shangqiu Agricultural and Forestry Science Institute in 2015. To explore the suitable planting mode of‘Shangmai 156’, this experiment used the local traditional row spacing planting as the control to study the effect of row spacing and sowing amount on the growth and yield of wheat. The results showed that with the increase of seeding rate, the plant height and PAR value at 20 cm of canopy increased, the secondary root, tiller number, dry weight and PAR value at the bottom of canopy decreased, the larger the sowing amount, the more the number of panicles per hectare was, the less the number of grains per panicle and the 1000-grain weight were, and the difference in wheat yield under the treatment of high seeding rate (195 kg/hm2) and medium seeding rate (150 kg/hm2) was not significant, but both were significantly higher than that under the treatment of low seeding rate (120 kg/hm2); under the same seeding rate (150 kg/hm2), wide- narrow row treatment could reduce plant height, increase the number of secondary roots, tiller number, dry weight and PAR proportion at the bottom of the canopy, and coordinate the number of panicles per hectare, grain number per spike and 1000-grain weight, and increase the yield of wheat. In conclusion,‘Shangmai 156’is suitable for wide-narrow row planting, and the suitable seeding rate is 150-195 kg/hm2.

  Effects of Combined Pollution of Pb and Cd on Growth and Nutritional Quality of Chinese Cabbage Varieties 2019, 35 (9):  12-21.  DOI: 10.11924/j.issn.1000-6850.casb18100117 Abstract + ( 663 )   PDF ( 1313KB )   ( 282 ) To screen out high- quality, low- accumulation Chinese cabbage varieties adapted to lead and cadmium combined contaminated soil, 15 Chinese cabbage varieties were planted in four kinds of lead and cadmium combined contaminated soil, the effects of heavy metals on the growth of various varieties were determined by measuring the plant height and fresh weight of each cabbage; the lead and cadmium content were determined by atomic absorption spectrometry; the vitamin C content was determined by 2,6- dichlorophenol indophenol titration method; the nitrate content was determined by salicylic acid method and the soluble protein content was determined by Coomassie Brilliant Blue G- 250 method. Results of the pot experiments revealed that with the increase of lead and cadmium concentration, the plant height and edible fresh weight of Chinese cabbage increased first and then decreased. And the effects of heavy metal lead and cadmium on different Chinese cabbage varieties were different. With the aggravation of combined lead and cadmium stress, the content of lead and cadmium in the edible parts of the 15 varieties increased. Under mild pollution treatment, there was no significant difference in Cd content among the varieties, the lowest Pb content was found in‘Yihekuaicai1269’, followed by that of‘Cuinenpiaoerbai’, which was 0.05 and 0.06 mg/kg, respectively. However, the nitrate content of‘Yihekuaicai1269’exceeded the standard, while that of ‘Cuinenpiaoerbai’ was relatively low. Under moderate pollution treatment, only Pb and Cd of ‘Yihekuaicai1269’did not exceed the standard, but its nitrate content exceeded the standard. Under severe pollution treatment, there was no cabbage variety that met the requirements. Under the mild pollution treatment, the determination of vitamin C content and soluble protein content of cabbage found that the Vc content of‘Cuinenpiaoerbai’was the second, and the soluble protein content was the third, so it was a relatively high quality Chinese cabbage variety. ‘Cuinenpiaoerbai’is a low- accumulation, high- quality Chinese cabbage variety that is suitable for planting in light lead-cadmium combined contaminated soil.

  Correlation analysis between yield per plant and agronomic traits of Interspecific Hybrid between Brassica napus.L and Brassica japonica Sieb 2019, 35 (9):  22-27.  DOI: 10.11924/j.issn.1000-6850.casb18100119 Abstract + ( 792 )   PDF ( 1094KB )   ( 252 ) The aims are to clarify the effects of characters on the yield per plant of interspecific hybrid between Brassica oleracea L. and Brassica rapa, and to promote the application of new interspecific hybrid in breeding. The agronomic characters of 133 BC1F4 individuals were analyzed with variation analysis, correlation analysis, path analysis and principal component analysis. The results showed that the number of invalid siliques had the maximum variation while plant height had the minimum variation. The yield per plant was positively correlated with plant height, the first branch height, the length of main inflorescence, the number of primary branches, the number of invalid siliques on main inflorescence, seed number per silique and the 1000-seeds weight, among which the yield per plant had significantly positive correlation with plant height. The main affecting factors of yield were: plant height, primary branch height, number of siliques on secondary branch and number of efficient siliques on main inflorescence. Moreover, the principal component analysis sorted the characters into 5 categories: the 1st and 3rd category controlled the yield and the other three were responsible for plant height, main inflorescence-controlling characters and branch-controlling characters, respectively. Thus, the yield per plant of interspecific hybrid between Brassica oleracea L. and Brassica rapa was mainly affected by plant height, the first primary branch height, the number of siliques of the secondary branch and the number of siliques on main inflorescence.

  Related Factors Analysis of Grape Downy Mildew Initial Occurrence 2019, 35 (9):  28-33.  DOI: 10.11924/j.issn.1000-6850.casb18100073 Abstract + ( 612 )   PDF ( 1159KB )   ( 249 ) To clarify the relationship between the initial occurrence of grape downy mildew and sporangia, meteorological factors and grape varieties, the initial occurrence periods of grape downy mildew of Ruby Seedless, Muscat Hamburg and Cabernet Girnischt were investigated for 6 consecutive years. A spore trap device was installed to collect the grape downy mildew spores in the air. The meteorological data of field were detected by a small climate station. The relationships between temperature, humidity, rainfall and the initial occurrence of grape downy mildew were analyzed. The results showed that downy mildew spots were seen in field after 10 days of the discovery of grape downy mildew spores. The downy mildew occurrence period of different grape varieties was different, that of Ruby Seedless was the earliest, followed by that of Muscat Hamburg fragrance, and then was that of Cabernet Girnischt. The incidence of grape downy mildew was closely related to temperature, humidity and rainfall, in which the rainfall was the main factor. Based on the above data analysis, this study proposes a direct and simple method for the prediction of grape downy mildew, which could be a basis for the prevention and control of this disease.

  Regulating Mechanism of Rose Flowering and Senescence: Research Progress 2019, 35 (9):  34-38.  DOI: 10.11924/j.issn.1000-6850.casb17120027 Abstract + ( 659 )   PDF ( 1190KB )   ( 369 ) Roses hold high symbolic value and great cultural importance in different societies throughout human history. They are widely used as garden ornamental plants, as cut flowers, and for the production of essential oils for the perfume and cosmetic industries. Opening and senescence of rose flower is still an unsolved problem in the world of floriculture industry and the mechanism behind the onset of the very early events still remains to be elucidated. In this review, we comment on the physiological and molecular mechanism on flower buds opening and senescence of roses. Physiological and genetic factors regulating rose flowering and senescence were discussed. Furthermore, we analyzed the effects of hormones, water metabolism, sugar metabolism, respiration, antioxidant system and other physiological processes during rose flower senescence, and provide some ideas for future breeding direction of cut rose flowers.

  Formulation Optimization of Shuangmei Juice Beverage 2019, 35 (9):  39-45.  DOI: 10.11924/j.issn.1000-6850.casb17110117 Abstract + ( 552 )   PDF ( 1252KB )   ( 333 ) To explore the techniques for making Shuangmei juice beverage with aroma and taste good, first, the single-factor random block experiment was used to study the process parameters of extracting roselle juice, and then, the roselle juice was used as raw material to clarify the effect of the rose juice, sucrose, fructose syrup and citric acid on the appearance quality of the beverage. Based on this, orthogonal design experiments were carried out to explore the optimal ratio of the original rose juice, sucrose, fructose syrup and citric acid required for the production of the beverage. The results showed that: (1) the ratio of material to liquid, the extraction time, the extraction temperature and licorice all affected the sensory quality of roselle juice, the extraction parameters of roselle juice were: ratio of material to liquid of 1:80, the extraction time of 40 min, the leaching temperature of 75℃, and the adding amount of licorice of 0.4%; (2) rose juice mainly affected the rose flavor quality of Shuangmei juice beverage, and its dosage should be 2%-4%, sucrose mainly affected the sweetness, and its dosage should be 3%-4%, glucose syrup mainly regulated the sweetness and reduced the dosage of sucrose, its dosage was preferably 2%-4%, the citric acid mainly affected the sour taste, and the dosage should be 2%-4%; (3) the best blending scheme for the production of Shuangmei juice beverage was 1.25% roselle extract juice+ 4% rose juice+ 2% sucrose+ 2.5% fructose syrup+ 0.12% citric acid. The Shuangmei juice beverage processed by this technique process is a healthy flower drink with soft color and rose fragrance.

  Optimization and Improvement of Detection Conditions for Potassium, Calcium and Magnesium in Plants by Hydrochloric Acid Extraction-AAS Method 2019, 35 (9):  46-52.  DOI: 10.11924/j.issn.1000-6850.casb17110050 Abstract + ( 819 )   PDF ( 1284KB )   ( 374 ) To optimize the detection conditions, hydrochloric acid extraction- AAS method was used to determine the content of potassium, calcium and magnesium under different conditions, such as different particle size, oscillation time, temperature, extraction methods and concentrations of hydrochloric acid. The results showed that sieving 60 mesh plant particles were suitable for hydrochloric acid leaching method, suitable oscillation time was 90 min with hydrochloric acid soaking at room temperature. With hot hydrochloric acid soaking, the temperature of hydrochloric acid was 55℃ and suitable oscillation time was 60 min. Proper concentration of hydrochloric acid was 1 mol/L. The proper method of hydrochloric acid leaching sample was oscillation. Hydrochloric acid extraction- AAS method established in this experiment was accurate and efficient, economic and security, easy operation, it was suitable for inspection of batch sample.

  Extraction and Determination of Total Water-soluble Sugars in Cotton 2019, 35 (9):  53-60.  DOI: 10.11924/j.issn.1000-6850.casb17110066 Abstract + ( 702 )   PDF ( 1318KB )   ( 266 ) The reaction condition and extracting condition of the anthrone colorimetric method to determine the soluble sugar content of cotton were investigated in this paper. The results showed that the optimum determination condition was: detector wavelength of 575 nm, color- display reagent consumption of 5 mL, reaction time of 10 min, reaction stalling time of 10 min to 1 h. Under this condition, there was a good linear relationship between the concentration of glucose and absorbance (C= 0.1318A + 0.0004， R2=0.9992). The limit of detection (LOD) for glucose of the proposed method was 0.003 mg/mL. The relative standard deviation (RSD) and the average recovery rate of the method was 0.04 and 100.3% , respectively, which denoted high repeatability and precision. Hence the established method is simple, economical, rapid and accurate, and suitable for routine analysis of bulk samples.

  Diversity Analysis of Culturable Bacteria in Intestine of Drosophila melanogaster and Drosophila suzukii 2019, 35 (9):  61-67.  DOI: 10.11924/j.issn.1000-6850.casb17100064 Abstract + ( 599 )   PDF ( 1626KB )   ( 235 ) To understand the intestinal bacterial diversity in Drosophila suzukii and D. melanogaster, the bacteria in eggs, the intestine of larvae, pupae and adults of two Drosophila species were separated and purified, and identified with 16S rDNA genetic analysis. The results showed that, the number of bacteria was the lowest in eggs and the highest in larval intestine at different developmental stages of the two Drosophila species. And the number of bacteria in D. suzukii was more than that in D. melanogaster ignificantly. 31 species of bacteria were isolated from the two Drosophila species, the bacteria of Proteobacteria was the dominant population. The species of bacteria were 20 and 21 in D. suzukii and D. melanogaster, respectively. Therein, there were 13 species in both the two Drosophila species. The stable bacteria in intestine of D. suzukii were Citrobacter freundii, Klebsiella oxytoca, Chryseobacterium sp. and Lysinibacillus fusiformis. While, Acetobacter thailandicus, Paenibacillus taichungensis, Providencia rettgeri and Morganella morganii were stable bacteria in intestine of D. melanogaster. It is concluded that, the number and species of bacteria in D. suzukii and D. melanogaster are different at different development stages.

  Pathogen Isolation of Fusarium Wilt of Island Cotton and Indoor Fungicides Screening 侯 仙,王梦瑶,邓亚辉,张 桦 and 2019, 35 (9):  68-74.  DOI: 10.11924/j.issn.1000-6850.casb18010093 Abstract + ( 554 )   PDF ( 1308KB )   ( 206 ) The aims are to screen out the chemicals that can effectively control cotton wilt, reduce blindness of farmers’medication, improve control level of the disease, and enhance economic benefits of cotton in Xinjiang. 4 strains with cotton wilt pathogen were identified by separation and purification, Koch’s postulate and sequence analysis. 4 fungicides 100 billion/g Bacillus subtilis WP, 8% Ningnanmycin AS, 0.3% Tetramycin AS, 80% mancozeb WP were selected to detect the toxicity for DD64, DD89, DD11 and DD22 pathogenic strains. It was identified that the 4 pathogenic strains were strong pathogenic strains. The results showed that for the DD64 and DD89 in northern Xinjiang, the inhibitory rate of 100 billion/g Bacillus subtilis WP was the best, 96.47% and 95.29% , respectively, followed by 0.3% Tetramycin AS. For the DD11 and DD22 strains in southern Xinjiang, the antibacterial effect of 0.3% Tetramycin AS was the best, 97.91% and 99.35% , respectively, followed by100 billion/g Bacillus subtilis WP. In the toxicity determination of DD64 and DD89, the 8% Ningnanmycin AS had the strongest virulence, and the EC50 values were 0.044 mg/L and 0.046 mg/L, respectively. In production, 0.3%Tetramycin AS is recommended to prevent the expansion and spread of the disease in the early stage. 100 billion/g Bacillus subtilis WP and 8% ingnanmycin AS could be used as rotation agents to effectively control the disease.

  Research Progress of Plant bHLH Transcription Factor Yu bing,,李海英,, and Duanmu Huizi 2019, 35 (9):  75-80.  DOI: 10.11924/j.issn.1000-6850.casb18100098 Abstract + ( 1387 )   PDF ( 1277KB )   ( 517 ) The bHLH transcription factors are one of the largest families of transcription factors in plants. In order to understand the functions and structure features of plant bHLH transcription factors, we clarify the structure features of bHLH transcription factors, and summarize the functions of plant bHLH transcription factors, including bHLH transcription factors regulating signal transduction, bHLH transcription factors regulating plant development, and bHLH transcription factors taking part in plant stress resistance. But the next step is still to systematically classify and analyze the functions of the gene family, in particular, the study of bHLH transcription factors in other non-model organisms should be strengthened.

  Landscape Pattern Change of Land Use in Huangshi City 王晓娜,牟惟勇 and 2019, 35 (9):  81-85.  DOI: 10.11924/j.issn.1000-6850.casb18100062 Abstract + ( 702 )   PDF ( 2551KB )   ( 201 ) To reveal the landscape pattern development and change of land use and rationally utilize land in Huangshi City, Hubei Province, the Landsat remote sensing images of 2004, 2011 and 2016 were selected to analyze the land use change of various types of land by adopting the theory of landscape ecology and the technology of GIS. The number of patches, patch density, aggregation index, the largest patch index, landscape shape index, contagion index, Shannon diversity index, and Shannon evenness index were selected to study the landscape pattern of Huangshi City in recent 15 years. The results showed that the area of farmland and construction land increased, the area of woodland and water area basically remained unchanged, the number of bare land decreased, the landscape connectivity weakened, the fragmentation increased, the complexity of landscape pattern increased, and the landscape pattern was aggravated by human activities.

  Optimization and Simulation of Urban Land Use Pattern Based on the Perspective of Objective Constraint: A Case of Hohhot 2019, 35 (9):  86-94.  DOI: 10.11924/j.issn.1000-6850.casb18100057 Abstract + ( 560 )   PDF ( 2255KB )   ( 150 ) The paper aims to solve the problem of matching the allocation of urban land resource with economic construction requirement to the greatest extent degree, so that convenience to realize the objective of maximizing the comprehensive benefit of urban land use. Take the municipal districts of Hohhot city as a case study area, combined with the structure of urban land use change characteristics in the area from 2001 to 2016, respectively using the goal programming method and analytic hierarchy process to forecast and merit land demand scheme in 2030 based on the objects of economy and society benefit, and simulate space layout and make decision for the optimization scheme of the best benefit target of the above two kinds of target by CLUE-S model. The results showed that: (1) the total area of urban construction land in the study area increased to 94.104% from 2001 to 2016, with the land used of the biggest increase of the two types for the transportation land and residential land. (2) Different from present situation of the urban land use structure change trend, the biggest growth of the urban construction land classes are commercial land and industrial and mineral storage land respectively based on the optimization target of economic benefits and social benefits, and the equilibrium degree of the two kinds of schemes of urban construction land use structure are higher than the status values of 2016 year are 0.259 and 0.462 respectively, the urban construction land kind composition in the area tends to be dynamically balanced development momentum. (3) The forecast urban construction land area of economic benefit optimization scheme is 30.828 km2 higher than the social benefit scheme. Starting from the theoretical principle of achieving the best comprehensive benefits of land use, due to that the social benefit optimization scheme is better than the economic benefit plan in the dynamic balance of urban land structure and layout, and it becomes the best urban land optimization scheme.

  Farmland Abandonment on the Loess Plateau of Longdong Region During the Past 20 Years and Its Driving Force: A Case Study of Kongtong District, Pingliang City, Gansu Province 2019, 35 (9):  95-101.  DOI: 10.11924/j.issn.1000-6850.casb18050136 Abstract + ( 581 )   PDF ( 2515KB )   ( 196 ) To understand the reason of cropland abandonment and protect quantity and quality of farmlands and then ensure national food security and social stabilization, based on the Landsat TM/OLI remote sensing data and data of questionnaire survey, the spatial and temporal distribution and driving force of cropland abandonment in Kongtong District was studied by satellite image interpretation and binary logistic regression model. The results showed that: (1) from 1995 to 2015, the area of abandoned farmland in Kongtong District increased by 5012.06 hm2, which included 3221.13 hm2 during the first ten years and 1790.93 hm2 during the next decade; (2) in the past two decades, the abandoned farmland mainly distributed on the hillside field of mountainous region of slope between 5°and 20°; (3) among the 10 factors affecting farmland abandonment in Kongtong District, except the regression coefficients of the family size, the farmland quantity and the yield were relatively small; other factors had greater regression coefficients. Therefore, in Kongtong District, socioeconomic factors were the primary driving forces for the farmland abandonment, and the land marginalization, which was due to the drastic increase of farming opportunity cost, was the fundamental cause, while the direct factor for abandonment was the shrink of agricultural labor forces.

  Remediation Techniques Removing Antimony from Water: Research Progress 2019, 35 (9):  102-108.  DOI: 10.11924/j.issn.1000-6850.casb17110079 Abstract + ( 507 )   PDF ( 1281KB )   ( 459 ) The paper aims to study the remediation techniques of antimony (Sb), and summarize the concerning research in recent 10 years. The paper introduces the chemical forms and contamination sources of Sb which are relevant aspects to understand and develop remediation techniques. The most common removal techniques of Sb (adsorption, coagulation/flocculation and electrochemical methods) are presented with discussion on their advantages and drawbacks. Literature review on adsorption focuses on detail. Recent researches have focused especially on available low- cost adsorbents, such as carbon materials, biosorbents, minerals and metallic oxides. Maximum adsorption capacities and other details are accurately compiled for Sb (III, V) species. Some aspects related to economic aspects and adsorption mechanisms are also discussed. The present removal techniques can hardly meet the demands, and some researches in adsorption of Sb should be strengthened in the future. Therefore, the development and preparation of new efficient adsorbents is very important.

  Nutrient Input Affects Soil Nutrients in Pinggu Peach Orchards 2019, 35 (9):  109-114.  DOI: 10.11924/j.issn.1000-6850.casb17090146 Abstract + ( 537 )   PDF ( 1235KB )   ( 181 ) In 2016, 101 peaches in Pinggu District were studied, and the status of fertilization and its effect on soil nutrient were investigated. The results showed that the organic fertilizer investigated in peach orchards was mainly composed of chicken manure, sheep manure, pig manure and cow dung, while the chemical fertilizer is mainly compound fertilizer or NPK with the application. In 2016 total N, total P2O5 and total K2O inputs is 1.6 times, 1.6 times and 1.8 times higher than in 2006.Due to the excessive nutrient input in peach orchards for years. in 2006, the contents of soil organic matter, total nitrogen, available nitrogen, available phosphorus and available potassium in peach orchards were significantly higher than those in 2006 or the second soil survey in 1981.According to the survey results, the change trend of average alkali nitrogen content in soil was not obvious as nitrogen fertilizer was applied in the soil, the average effective phosphorus content increased significantly as phosphate fertilizer was applied in the soil, and the content of available potassium in soil increased first and then decreased as the potash input was increased.The average available N content in the soil with the application of nitrogen fertilizer increased significantly with the increase of the amount of potassium fertilizer. The content of available potassium in the soil was the highest Rising trend after falling. The results also showed that the nitrogen surplus of Pinggu soil was 444.6 kg N / hm2, and crop nitrogen absorption / nitrogen application accounted for only 45%; phosphorus surplus of Pinggu soil was 516.6 kg N / hm2, and crop phosphorus absorption / phosphorus application accounted for only 22%; thus it can be seen, the nitrogen and phosphorus nutrient surpluses in peach orchards have resulted in increased risk of soil nitrogen and phosphorus in orchard soils.Therefore, peach orchards are to carry out a reasonable nutrient management to ensure the formation of production and quality, and the sustainable development of peach orchards.

  Applicability and Revision of MCI in Sichuan Province 2019, 35 (9):  115-121.  DOI: 10.11924/j.issn.1000-6850.casb17110072 Abstract + ( 1052 )   PDF ( 1292KB )   ( 803 ) Based on the daily meteorological data and the drought disaster data of 156 stations in Sichuan Province during 1991-2013, the classification standard of the actual drought disasters was established with the method of grey correlation. The applicability of MCI in Sichuan Province was analyzed, and which was revised by using the method of projection pursuit. The results showed that the grey correlation degree of selecting three indexes of crop disaster area, social disaster population and direct economic loss could well describe the comprehensive loss of drought disaster. The applicability analysis showed that the accuracy rate of drought grade assessment based on MCI was generally low, of which the special drought occurred 21 times, and the MCI evaluation result reached 115. The inaccurate assessment of drought levels might be related to the gradual improvement of irrigation and water capacity in Sichuan province. Based on the reference sequence of the disaster grey correlation degree, the influence of each component of MCI on the actual drought was revealed by the projection pursuit method, and the optimal projection direction was found, and the revised coefficient of MCI indexes were established. Compared with MCI, the revised MCInew had significantly improved the evaluation ability of drought grade, and the accuracy of drought assessment increased from 16.5% to 62.5%. A case study also indicated that MCInew was more consistent with the actual drought occurrence and development.

  Change Trend of 10℃ Accumulated Temperature in Panzhihua Tobacco Planting Area from 1980 to 2013 2019, 35 (9):  122-126.  DOI: 10.11924/j.issn.1000-6850.casb17110093 Abstract + ( 458 )   PDF ( 2666KB )   ( 189 ) To investigate the thermal condition of Panzhihua tobacco planting area from 1980 to 2013, the spatial pattern and change trend of the 10℃ AAT in Panzhihua tobacco planting area were analyzed, and the differences among regions and districts were compared, to provide data support for the formulation of the corresponding cultivation and cultivation system of flue-cured tobacco on the basis of heat conditions. The results showed that: the 10℃ AAT was higher in the east and west district of southern Panzhihua and Renhe County than that in Yanbian and Miyi County of northern Panzhihua, and presented an increasing trend (5.44℃/a) from 1980 to 2013. The east and west district and Renhe County are located in the valley of Jinsha River, which has higher 10℃ AAT and obvious change trend, Miyi and Yanbian have high altitude and low change trend, Miyi has the lowest change trend of 10℃ AAT, and the changing curve of these two counties is relatively uniform due to the same latitude.

  Citrus Quantitative Drip Irrigation Model Based on Meteorological Factors 2019, 35 (9):  127-131.  DOI: 10.11924/j.issn.1000-6850.casb18100069 Abstract + ( 651 )   PDF ( 1520KB )   ( 269 ) To accurately estimate the drip amount of irrigation and fertilization of citrus, and to realize the remote control of start and end time for drip irrigation by mobile APP, we constructed the water requirement model at different growing stages of citrus in Guilin and conversion algorithm modes between meteorological factors (such as precipitation) and soil weight moisture capacity on the basis of analyzing the citrus phenological period from 1994 to 2015 in Guilin and the meteorological conditions; in addition, we clarified the drip irrigation technology process of citrus, and estimated the amount of drip irrigation in a citrus planting demonstration base of Nanning by applying the model to the drought occurred in March 1997. The results showed that: the model for estimating the amount of drip irrigation could save more than 40% water compared with the traditional model. It has significant reference for building the innovative service mode of“weather monitoring and forecasting information + large- scale production management facilities + feedback and interaction of production information”.

  Ecological Grass Husbandry in China: Analysis and Evaluation of the Policies 2019, 35 (9):  132-137.  DOI: 10.11924/j.issn.1000-6850.casb17110074 Abstract + ( 814 )   PDF ( 1157KB )   ( 383 ) The paper aims to provide a decision support for making long-term policy, based on the policy analysis framework from Liu Xielin, we analyzed the grass husbandry policies promulgated since 2000 and identified the gap of grass husbandry policy implementation. We found that: with implementation of grass husbandry policies, the ecological function of grassland was restored, but the economic function was neglected, there was a conflict between ecological protection and income increase of farmers and herdsmen, and there were still deficiencies in grassland management and major disaster prevention and so on. So, the policies should be implemented by coordinating the grass production function on the basis of grassland protection, and the reasonable utilization of grassland resources could be realized through the innovation of land management and grassland management patterns, strengthening the scientific research investment, improving the response capacity to major disaster emergencies, thus to promote the economic development in grassland area with recovering grassland ecology at the same time.

  The Concentration of Cu2+: Effects on Germicidal Efficacy in Recirculating Aquaculture System 2019, 35 (9):  138-142.  DOI: 10.11924/j.issn.1000-6850.casb18090064 Abstract + ( 631 )   PDF ( 1375KB )   ( 276 ) The paper aims to study the effects of concentration of Cu2+ in the recirculating aquaculture system on the purification efficiency of the system. Adding Cu2+ through the generator in the recirculating aquaculture system, we evaluated the germicidal efficacy by monitoring water quality and the health of zebrafish. The results showed that: the increase speed R2 of Cu2+ in the generator was 0.9942 with better stability; after 24 h, when the concentration of Cu2 + got to 0.76 mg/L, the zebrafish began to die; in the same concentration, the lower the temperature, the higher the zebrafish’s tolerance to Cu2 + ; in the same temperature, the zebrafish could die faster with the increasing concentration of Cu2+; in the safe concentration (the concentration of Cu2+ was 0-0.23 mg/L), the suitable breeding temperature was (26±2)℃ and the Cu2 + could inhibit the bacteria effectively when the concentration was 0.14-0.226 mg/L. We make a 20-day zebrafish fishing test to verify the results, the concentration of nitrate nitrogen, nitrite nitrogen, TAN change similarly when the concentration of Cu2 + get higher; the concentration of nitrate nitrogen, nitrate nitrogen, TAN and the total number of bacteria keep in a stable state when the concentration of Cu2+ is 0.1-0.2 mg/L and the breeding temperature is (26±2)℃, and this condition is beneficial for the growth of zebrafish.

  Toxicity Test of Six Fungicides on Fusarium Oxysporum Infecting Cucumber 2019, 35 (9):  143-148.  DOI: 10.11924/j.issn.1000-6850.casb17110081 Abstract + ( 984 )   PDF ( 1325KB )   ( 234 ) The aim of this studyis to identify the inhibitory effects of six fungicides by the growth rate method on toxic culture medium. The colony diameterwasused as observation index. The colony diameters of the control group and the treatment group were detected, and the inhibitory effects offungicides on Fusarium Oxysporum were measured by inhibition ratio. The results showed that72 hours after medication, propiconazole had the maximum toxicity index and the best inhibition effect onFusarium oxysporum with EC50 value of 0.9039 mg/L, followed by mancozeb and isopeptide, with the EC50 value of 2.8939 mg/L and 6.8186 mg/L, respectively. Kresoxim- methyl and pyrimethanil had normal effects,with EC50 value of 29.3951 mg/L and 30.4126 mg/L, respectively. Difenoconazole had the minimumtoxicity index and the least effect, with EC50 value of 143.2943 mg/L. In conclusion, propiconazole hasthe best inhibition effect.

  Status Quo and Competitiveness of Agricultural Products Export in China 2019, 35 (9):  149-154.  DOI: 10.11924/j.issn.1000-6850.casb17110036 Abstract + ( 1543 )   PDF ( 1313KB )   ( 595 ) With the implementation of the free trade zone strategy, China’s agricultural products export will enjoy good opportunities for development. However, the pressure for domestic agricultural products market to open up will also increase. Under such circumstances, how to bypass the disadvantages and improve the export competitiveness of China’s agricultural products to maximize the benefits of agricultural trade becomes particularly important. From the perspectives of trade balance in agricultural products, producing areas and destinations of export products and the main exporters, we analyzed the status quo of China’s agricultural products export. Based on this, the International Market Share (IMS), the Revealed Comparative Advantage Index (RCA) and the Competitiveness Index (CI) are chosen to measure and analyze the export competitiveness of China’s agricultural products. The results show that the overall export competitiveness of China’s agricultural products is relatively weak and needs to be further improved. Measures, such as adjusting the industrial structure of agriculture, promoting the added value of agricultural products, enhancing the brand effect and actively developing the emerging markets, should be adopted to further strengthen the export competitiveness of China’s agricultural products.

  National-scale Mapping of Winter Wheat in China Using GF-1 Imagery 2019, 35 (9):  155-164.  DOI: 10.11924/j.issn.1000-6850.casb18100006 Abstract + ( 657 )   PDF ( 4442KB )   ( 341 ) To realize the automatically extraction of winter wheat, a classification algorithm based on weighted NDVI index (WNDVI) is proposed to construct the winter wheat classification units. Based on the WNDVI, the division thresholds between winter wheat area and other areas were determined by an adaptive method. Taking GF-1/WFV images from October 2013 to May 2014 as an example, WNDVI from 1180 classification units of 14 provinces (city and regions) in China was created. Spatial distribution maps of major winter wheat production areas were produced in 2014. The accuracy verification of the results was conducted with 14233 samples, and the overall accuracy reached 90.6%. The proposed method is highly automated, its results are stable, and it is suitable for large-scale monitoring of winter wheat areas.