Current issue

• 2020 Vol.36 No.7 Published:05 March 2020

  Elite Germplasm ‘Ningchun 48’: Analysis of Early Maturity Characteristics Chen Xiaolong, Li Qianrong, Tao Yuan, Zhang Zhensuo, He Lianxiang 2020, 36 (7):  1-5.  DOI: 10.11924/j.issn.1000-6850.casb18110064 Abstract + ( 459 )   HTML ( 1 )   PDF ( 1261KB )   ( 76 ) To study the early maturity characteristics of spring wheat ‘Ningchun 48’, and provide a basis for breeding new spring wheat varieties with early maturing and high-yield in the irrigation districts along the Yellow River of Ningxia and utilizing the elite germplasm ‘Ningchun 48’, we studied the development progress, ear differentiation and grain filling characteristics of ‘Ningchun 48’, taking ‘Ningchun 4’, a local main late variety, as the control. The results showed that: ‘Ningchun 48’ matured 7 days earlier than ‘Ningchun 4’, it had short duration days of tillering and jointing stage, booting and heading stage, and the grouting duration days after heading and flowering was not shortened; ‘Ningchun 48’ had shorter ear length, fewer kernel number and spikelet number on account of the decrease of duration days of ear differentiation at single ridge stage, double ridges stage and floret primordium formation stage; ‘Ningchun 48’ started grouting earlier and the grouting days lasted longer, but the grouting rate was lower than that of ‘Ningchun 4’. It is suggested that the germplasm materials with early maturity, large spike, more grains per spike and high grouting rate should be selected for combination when ‘Ningchun 48’ is used as parent; during the selection process, by ensuring the early maturity and the long duration of grouting in the progeny materials, we should select the progeny materials with large spike, more grains per spike and high grouting rate.

  Drought Stress and Drought-resistant Maize Inbred Lines: Effects on Growth at Seedling Stage Zhang Fuguo, Wang Huaiping 2020, 36 (7):  6-10.  DOI: 10.11924/j.issn.1000-6850.casb18110087 Abstract + ( 417 )   HTML ( 0 )   PDF ( 1317KB )   ( 91 ) The effects of water stress on different drought-resistant maize inbred lines were studied at seedling stage, in order to provide reference for the selection of inbred lines for drought-resistant breeding. We studied the effects of drought stress on height, dry weight, leaf area, specific leaf weight, SPAD and net photosynthetic rate of drought-resistant and water-sensitive inbred lines of summer maize by using artificial water control. The results showed that: different drought-resistant varieties at seedling stage had different responses to water stress; under water stress, drought-resistant maize varieties showed obvious advantages, the plant height, dry weight of shoot and underground parts, leaf area, SPAD and net photosynthetic rate of drought-resistant maize varieties since five-leaf stage were higher than those of water-sensitive maize variety, and its specific leaf weight was relatively stable, indicating that compared with common inbred lines, the drought-resistant variety had better adaptability at seedling stage under drought condition. The study could enhance the selection and breeding of drought-resistant inbred lines and further improve the selection efficiency of drought-resistant and water-saving maize varieties.

  Phosphorous Utilization During Summer Maize Production in North China Lin Feiyang, Du Aifang, Xu Xiuchun, Meng Fanqiao 2020, 36 (7):  11-15.  DOI: 10.11924/j.issn.1000-6850.casb18110050 Abstract + ( 667 )   HTML ( 0 )   PDF ( 1342KB )   ( 96 ) The aims are to evaluate the phosphorous (P) utilization and influencing factors in summer maize production in North China, promote high-efficient utilization of P fertilizer, and decrease the loss and environmental pollution. The authors collected the researches on summer maize since 1980. The data of P fertilizer experiments on summer maize in North China were analyzed. The grain yield, straw yield and grain/straw ratio were obtained, and the relationship between fertilizer P rate and P content in the grain and straw of summer maize were obtained. The results showed that with the increase of P fertilizer, the apparent profit and loss of phosphorus linearly increased, and at the fertilizer P rate of 75 kg/hm 2, the apparent profit and loss of phosphorus was 0. The average P fertilizer efficiency of summer maize in North China was 15%, and the increase of nitrogen (N) fertilizer and its combining application with fertilizer P helped to increase P fertilizer efficiency. Summer maize had higher utilization efficiency of diammonium phosphate than calcium superphosphate, and the combination of organic and chemical P fertilizer also significantly increased P fertilizer efficiency. Among all the maize varieties, ‘Tiantai 60’ had the highest P efficiency. In summer maize production in North China, the application of diammonium phosphate and N fertilizer of appropriate level, and the combination of organic and chemical P fertilizer can improve the utilization efficiency of P fertilizer, decrease its loss, and reduce the risk of environmental pollution.

  Effect of Seed Priming on Sweet Sorghum Seed Germination and Seedling Growth Under Alkaline Stress Cui Fengjuan, Wang Zhenguo, Xu Qingquan, Li Mo, Li Yan, Deng Zhilan 2020, 36 (7):  16-21.  DOI: 10.11924/j.issn.1000-6850.casb18120005 Abstract + ( 417 )   HTML ( 1 )   PDF ( 1243KB )   ( 132 ) To study the effect of seed priming under alkali stress on germination and seedling growth, seeds of sweet sorghum hybrid combinations of ‘Tongtian No.1’ were primed with 500 μmol/L γ-aminobutyric acid (GABA). The primed seeds were subjected to mixed alkalis (NaHCO3:Na2CO3=5:1) stress of 3 levels (0, 50 and 100 mmol/L) in a pot culturing experiment. The effects of the seed priming and alkalis stress on seed, germination and seedling growth were then investigated. The results showed that with the alkali stress concentration increased, whether the seeds were primed or not, the amount of water absorbed by seeds, the germination index, the rate of seed emergence and the seedling survival rate dropped significantly, while the seedling growth was inhibited, and biomass accumulation decreased. Compared with unprimed seeds under the same alkalis concentration, the amount of water absorbed by seeds, the germination index, the growth of the embryo and the leaf area of seedlings of the primed seeds all significantly increased. Compared with unprimed seeds under low alkali stress, the primed seeds had higher emergence rate and seedling survival rate, and the plant height and stem thickness up to 7 d and the total biomass all significantly increased. The results suggest that seed priming could promote sorghum seed germination under alkalis stress, alleviate seedling damage by alkalis stress, accelerate seedling growth and increase seedling alkalis tolerance.

  Filter Mud: Application Effect on Improving Acidic Soil and Promoting Sugar Beet Growth Li Renren, Lv Chunhua, Yu Lihua, Wang Yuguang, Geng Gui 2020, 36 (7):  22-28.  DOI: 10.11924/j.issn.1000-6850.casb20190900628 Abstract + ( 753 )   HTML ( 3 )   PDF ( 1308KB )   ( 67 ) To provide the sugar mill with a comprehensive utilization method of filter mud, with the beet variety ‘H004’ as the experimental material, we studied the effects of beet filter mud on soil physicochemical properties, growth indexes, chlorophyll content, antioxidant enzymes and osmotic regulatory substances of beet seedlings by applying sugar mill filter mud equivalent to 1%, 3% and 5% of the dry weight of acid soil. The results showed that: with the increase of the proportion of filter mud applied, the soil pH gradually increased, and the content of available nitrogen, phosphorus and potassium gradually increased; the plant height, leaf width, leaf weight and stem weight of beet all increased gradually, and chlorophyll content of beet plants also increased gradually; the activities of catalase and peroxidase as well as the contents of proline, soluble sugar, soluble protein, reducing sugar and free amino acid all increased with the increase of the proportion of filter mud. Applying filter mud can improve the pH of acidic soil, and increase the content of available nitrogen, available phosphorus and available potassium in soil. Taking filter mud from sugar mill as soil improvement agent can not only improve the soil fertility and promote the growth of sugar beet, but also solve the problem of filter mud pollution and reduce the waste of resources to further protect the environment, which is of great economic and ecological significance.

  Chemical Fertilizer Reduction and Basal Application of Controlled Release Fertilizer After Green Manure Turned Down: Effects on Tobacco Yield and Quality and Soil Fertility Xiong Weiliang, Zhang Yingjie, Yang Peng, Tang Lili, Feng Wenlong, Zhang Minmin, Yuan Jiafu, Xu Xiangyu 2020, 36 (7):  29-36.  DOI: 10.11924/j.issn.1000-6850.casb20191000700 Abstract + ( 522 )   HTML ( 1 )   PDF ( 1460KB )   ( 65 ) To study the rational application of chemical fertilizer after green manure (pea, Pisum sativum) turned down, a field plot experiment was adopted to clarify the effects of basal fertilizer reduction and partially replaced by controlled-release fertilizer after green manure turned down on tobacco quality and output value and soil fertility. The results showed that green manure turned down could increase the content of organic matter in low organic matter soil (the contents of soil organic matter lower than 10 g/kg), but had no significant effect on other soil chemical properties. There was no significant effect on the yield and output value of tobacco leaves and the chemical composition of tobacco leaves when the basal chemical fertilizer was reduced by 15% and 30% after green manure turned down. After reducing the base fertilizer by 15%, replacing 50% of the remaining basal fertilizer with controlled-release fertilizer could significantly increase the yield and output value, as well as the potassium content and potassium/chlorine ratio of tobacco leaves.

  Tobacco and Green Manure Interplanting in Cold Region: Effect on Growth and Economic Characteristics of Flue-cured Tobacco He Guoqiang, Wang Panpan, Gao Yuan, Lu Xiaohua, Cao Yafan, Zhao Dongxue, Wang Jingying 2020, 36 (7):  37-43.  DOI: 10.11924/j.issn.1000-6850.casb18110066 Abstract + ( 498 )   HTML ( 1 )   PDF ( 1335KB )   ( 69 ) This study aims to develop low-carbon tobacco agriculture and construct resource-conserving and environment-friendly agriculture, thus to promote the development of tobacco leaf with special characteristics and the sustainable development of the tobacco leaf industry. Based on interplanting of tobacco with green manure (Medicago sativa, Melilotus officinalis, Lolium perenne, Triticum aestivum), the effect of interplanting with different green manures combined with the reduction of nitrogen fertilizer on the growth of flue-cured tobacco in field and the economic characteristics of post-flue-cured tobacco leaves was studied by using fixed-point trial. Results showed that interplanting with green manure in tobacco-growing field could significantly regulate the growth and development of tobacco plants, and contribute to accumulation of dry matter, and improve photosynthetic characteristic and economic benefit of flue-cured tobacco. For the agronomic traits and accumulation of dry matter of tobacco plants, the growth of tobacco plants interplanted with Medicago sativa+ 30%-reduction of nitrogen fertilizer treatment (Y3) was better than that of tobacco plants treated by conventional fertilization without reduction of nitrogen fertilizer (Y5). Likewise, treatment Y3 was better than treatment Y1, Y2 and Y4 in which tobacco plants were interplanted with Lolium perenne, Melilotus officinalis, and Triticum aestivum, respectively. Compared with treatment Y5, the maximum leaf length, maximum leaf width, maximum leaf area and accumulation of dry matter of treatment Y3 increased by 11.67%, 12.95%, 26.25% and 22.05%, respectively. Compared with treatment Y5, the SPAD value and photosynthetic characteristic of the tobacco plants interplanted with different green manures were improved to a certain degree, and interplanting green manure+ 30%-reduction of nitrogen fertilizer would not affect normal maturity and yellowing time of tobacco plants. At the same time, interplanting with green manure+ 30%-reduction of nitrogen fertilizer could significantly improve the relevant indexes of economic benefit of post-flue-cured tobacco leaves. The improving effect of the percentage of superior tobacco leaves of treatment Y1 was the best, and the improving effect of the percentage of medium and superior tobacco leaves, average price, yield and output value of flue-cured tobacco of treatment Y3 was the best. Compared with treatment Y5, the percentage of superior tobacco leaves of treatment Y1 increased by 9.86 percentage points. The percentage of medium and superior tobacco leaves, average price, yield and output value of treatment Y3 increased by 7.88 percentage points, 1.9 yuan/kg, 99.15 kg/hm 2 and 7584.91 yuan/hm 2, respectively. In general, Medicago sativa is the best green manure for soil fertility improvement in Heilongjiang.

  Historical Changes of Plant Community Structure and Biodiversity of Linpan: A Case Study in Pi County of Chengdu Li Yuan, Min Qingwen, Yang Liyun, Meng Fanxu, Yang Wanquan 2020, 36 (7):  44-49.  DOI: 10.11924/j.issn.1000-6850.casb18110111 Abstract + ( 496 )   HTML ( 0 )   PDF ( 1269KB )   ( 247 ) Linpan is a traditional rural settlement unit with distinctive characteristics and outstanding agricultural heritage conservation values in Chengdu plain. Plant is the key component of Linpan system and the study on historical change features of plant community can provide a scientific guidance for conservation efforts of Linpan in the study area. First, we analyzed the historical plant community structures by referring to historical data. Then a plant community investigation of 4 representative Linpan plots and 3 wood land plots along irrigation ditch was conducted in Pi County, Chengdu. Finally, we compared the plant community structures in different periods. The main changes of Linpan plant community include: Phoebe zhennan, Cunninghamia lanceolata and Platycladus orientalis were the dominant species in traditional Linpan, but now they have been replaced by Lindera megaphylla. An obvious degradation of bamboo forest could be observed in the study region. The species used to be prevalent in the wood land along irrigation ditch were Alnus cremastogyne and Platycladus orientalis, however these species have been replaced by Pterocarya stenoptera and Broussonetia papyrifera. Bamboo is not observed in the wood land along irrigation ditch. The social and economic changes in Pi County break the relationship between population, farm land and Lipan and ultimately result in the plant community changes.

  Main Botanical Characters of 56 Bitter Gourd Varieties Min Ziyang, Li Yongqi, Han Xiaoxia, Zhang Zhuqing, Yuan Zuhua, Hu Xinjun 2020, 36 (7):  50-54.  DOI: 10.11924/j.issn.1000-6850.casb18110078 Abstract + ( 703 )   HTML ( 0 )   PDF ( 1239KB )   ( 224 ) To scientifically evaluate the bitter gourd resources in southern China, the authors conducted the diversity, correlation and cluster analysis on major botanical characters of 56 varieties, including the fruit length, fruit width, fruit weight, internode length, stem diameter, leaf length, and leaf width. The results showed that the coefficient of variation was between 8.81% and 19.44%, with the average of 14.21%, the CV of fruit weight was the largest (19.44%) and that of the fruit width was the smallest (8.81%). Correlation analysis found that the agronomic characters of plants were correlated, leaf length and leaf width were positively correlated with the correlation coefficient of 0.978, and the negative correlation coefficient between the fruit weight and internode length was 0.451. The 56 bitter gourd varieties were divided into 3 groups by cluster analysis, of which 92.86% of the varieties belonged to group 1 and group 2, and only 4 varieties were in group 3. This research could provide references for cultivation and genetic improvement of bitter gourd resources in southern China.

  Regulation of Peat pH Value: Effect on Its Available Nutrients, and Seedling Growth of Tomato and Hot Pepper Dong Huan, Lou Chunrong, Zhang Qing, Han Yingzuo, Wang Hui 2020, 36 (7):  55-62.  DOI: 10.11924/j.issn.1000-6850.casb18110069 Abstract + ( 465 )   HTML ( 3 )   PDF ( 1595KB )   ( 56 ) To study the effect of pH value regulators on peat pH value, available nutrients, and seedling growth of tomato and hot pepper, potassium carbonate and calcium oxide were applied under different levels. The available nutrients of peat under regulator application were analyzed, the correlation between the application rates of pH value regulators and the available nutrients was studied, and the seedling growth indexes of tomato and hot pepper were compared. The results showed that the pH value, available P and available K of peat increased with the level of potassium carbonate, and the exchangeable Ca, Mg, Mn and available Fe of peat decreased with the level of potassium carbonate. The pH value and the exchangeable Ca of peat increased with the level of calcium oxide, the exchangeable Mg of peat increased firstly and then decreased with the level of calcium oxide, and the exchangeable Mn and available Fe decreased with the level of calcium oxide rapidly. The growth indexes of tomato seedlings and hot pepper seedlings both increased firstly and then decreased with the level of potassium carbonate and calcium oxide. Potassium carbonate was better than calcium oxide for improving the seedling growth of tomato and hot pepper. The seedling growth was improved by 2, 4, 6 g/kg of potassium carbonate and 0.8, 1.6 g/kg of calcium oxide significantly. The pH value of them was pH 5.05, 5.93, 6.28, 5.29, and pH 6.08, respectively. Four kinds of models between pH value and CI were built, and the optimal pH value of the models was pH 5.64, 5.84, 5.61, and 5.76, respectively.

  Comprehensive Evaluation of Perennial Ground-cover Plant Based on AHP in Wuhan Wu Hao 2020, 36 (7):  63-68.  DOI: 10.11924/j.issn.1000-6850.casb18110055 Abstract + ( 303 )   HTML ( 2 )   PDF ( 1249KB )   ( 82 ) To optimize plant introduction and landscape allocation in the ecological garden city construction, a comprehensive evaluation system of 51 new perennial ground-cover plants in Wuhan was constructed with Analytic Hierarchy Process (AHP) method, the ecological effects of cooling and humidification, carbon sequestration and oxygen releasing of these plants based on the calculated values were studied. The results showed that AHP method mainly focused on the length of green period, adaptability and ornamental effect of perennial ground-cover plants. The application values of 51 plant species were divided into 3 grades (16 spp. of I grade, 18 spp. of II grade and 17 spp. of III grade); Penstemon campanulatus, Limonium gmelinii, Coreopsis grandiflora had a relatively high ability of cooling and humidification, while Coreopsis grandiflora, Lavandula angustifolia, Lagerstroemia indica had a relatively high ability of carbon sequestration and oxygen releasing; plant species of AHP I grade had significantly higher carbon sequestration and oxygen releasing than those of AHP III grade. Taken together, the authors recommended that selecting plant species based on the AHP comprehensive evaluation, ecological effects and current habitat condition is beneficial for applying and popularizing the suitable ground-cover plants.

  Dwarfing Agent: Mechanism of Action and Research Progress in Ornamental Plant Zhong Yingying, Liao Yi, Lu Shunjiao, Li Chonghui, Li Kelie, Ning Yunfen 2020, 36 (7):  69-75.  DOI: 10.11924/j.issn.1000-6850.casb20191000718 Abstract + ( 506 )   HTML ( 2 )   PDF ( 1325KB )   ( 264 ) The paper described the mechanism and classification of dwarfing agents, analyzed their effect on the height, stress resistance, flowering index and endogenous hormone of ornamental plants, summarized their application methods, effect and persistence, and pointed out the existing problems. At present, the research on the dwarfing agents’ application in ornamental plants is not comprehensive, and the application time, the residue pollution and the dwarfing mechanism still need further study. In order to use the dwarfing agents more efficiently in the production process, studies on the various aspects of dwarfing agents should be further enhanced, so that the dwarfing agents can be widely applied to large-scale and industrial production of ornamental plants with dwarfing requirements, to improve the economic benefit, regulate and control the plant shape in accordance with the market demand, and promote the development of the ornamental plant industry.

  Soil Erosion in Loess Area of the Upstream of the Hutuo River: Spatial Characteristics Based on USLE Model Wang Bingzhe, Bi Rutian, Chen Ligen, Jing Yaodong 2020, 36 (7):  76-82.  DOI: 10.11924/j.issn.1000-6850.casb20190900654 Abstract + ( 422 )   HTML ( 0 )   PDF ( 1812KB )   ( 52 ) The Hutuo River is one of the large tributaries of the Haihe River in Shanxi. Studying the soil erosion in the upstream of the Hutuo River is of great significance for establishing the ecological restoration system of Shanxi. Taking the upstream of the Hutuo River in Xinzhou as the study area, based on the remote sensing image data, data elevation model data, rainfall data and soil type data, we estimated the soil erosion modulus of the upstream of the Hutuo River combined with GIS, RS, the US Universal Soil Loss Equation (USLE). The results showed that: (1) in 2015, the average soil erosion modulus of the upstream of the Hutuo River was 2538.9 t/(km 2·a), which was moderately erosive; the soil erosion types were mainly micro-erosion, extremely strong and severe erosion; (2) as the elevation rose, the higher the soil erosion intensity, the less the soil erosion area was, the elevation was positively correlated with the soil erosion intensity, and negatively correlated with the erosion area; severe erosion distributed in each elevation zone; the slightly erosion area was the largest in the [500,1000) elevation zone; (3) the soil erosion area of the study area was the largest in the 0-5° zone; (4) the soil erosion distribution of pasture and grassland was the widest, followed by cultivated land>forest land>garden land>urban village and industrial and mining land>water area and water conservancy facilities land>other land. The conclusion can provide a scientific basis for the government to adopt suitable soil erosion treatment technical methods, formulate treatment layout and scheme, and determine treatment types and scale.

  Effect of Tillage Management Modes on Farmland Physical Properties in Black Soil Region Ping Cuizhi, Hong Mei, Wang Wendong, Zhao Bayinnamula, Mei Li, Liu Pengfei, Zhao Wuyingga 2020, 36 (7):  83-89.  DOI: 10.11924/j.issn.1000-6850.casb18110065 Abstract + ( 413 )   HTML ( 0 )   PDF ( 1341KB )   ( 57 ) To understand the effects of different tillage modes on farmland physical properties in black soil region, a field experiment was conducted at the Arong Banner of Inner Mongolia from June to September, 2016. Three tillage modes included subsoiling (SS), no-tillage (MG) and conventional tillage (CK) were set up. By the collection of the soil samples from 0-10, 10-20 and 20-30 cm respectively, the soil bulk density, moisture and permeability were investigated. The results showed that the soil bulk density and moisture of the three tillage modes were in the order of SS>CK>MG; the eigenvalues of soil infiltration were in the order of initial infiltration rate> average infiltration rate> stable infiltration rate. The soil infiltration rate and cumulative infiltration were in the order of SS>CK>MG. Soil total porosity was the highest under SS treatment, and decreased with the increase of month. Principal component analysis showed that the initial infiltration rate and total infiltration amount were most sensitive to tillage modes, and could be used as evaluation indexes to investigate farmland tillage effect and mitigate black soil degradation in the black soil region of Northeast China. According to the comprehensive score, the performance of soil under different tillage modes was SS>MG>CK. In conclusion, subsoiling tillage could effectively reduce soil bulk density, increase soil water content, and promote soil permeability; no-tillage is more conducive to water conservation and reducing soil evaporation.

  Soil Moisture Differences of Automatic and Artificial Observation: Comparative Analysis Zhao Mengfan, Yan Liangdong 2020, 36 (7):  90-98.  DOI: 10.11924/j.issn.1000-6850.casb18110101 Abstract + ( 328 )   HTML ( 1 )   PDF ( 1418KB )   ( 67 ) Based on the soil moisture data of the parallel observation of DNZ2 and artificial drying method measured by Haibei Pastoral Test Station in Qinghai from July 28, 2017 to September 18, 2018, by comparing the differences, and calculating the probability of the differences and other relevant statistical methods, we analyzed the soil weight moisture capacity of 10-50 cm by layer. The results showed that: the data obtained by Haibei Pastoral Test Station were consistent with the data obtained by artificial observation during the study period; the soil weight moisture capacity observed by automatic station was lower than that by artificial observation, and the difference between 30 cm and 50 cm was relatively small, while the difference between 10 cm and 20 cm was relatively large; the data revision of the soil weight moisture capacity was conducted based on the data of automatic station and artificial observation, the results showed that all absolute errors were less than 3%, indicating that the soil moisture data by automatic observation in Haibei Pastoral Test Station could basically replace that by artificial observation. The study could provide certain technical support for promoting the automatic monitoring of agricultural meteorology.

  The Variation Characteristics of Main Meteorological Elements in the Northern Tibetan Plateau from 1973 to 2017 Ci Yang, Luo Sangpingcuo, Nor Bu 2020, 36 (7):  99-104.  DOI: 10.11924/j.issn.1000-6850.casb18110013 Abstract + ( 369 )   HTML ( 12 )   PDF ( 1933KB )   ( 926 ) To analyze the variation characteristics of main meteorological elements in the northern Tibetan Plateau under the global climate change, the trend analysis, wavelet analysis and mutational point analysis were used to study the multi-scale time-varying characteristics of the elements based on the monthly meteorological data. The results showed that: under the global climate change, the major meteorological elements in the study area changed significantly, and the temperature increased significantly at a rate of 0.45°C/10 a, and the wind speed decreased significantly at a rate of -0.27 m/(s·10 a), and the precipitation increased insignificantly at a rate of 6.48 mm/10 a; from the seasonal changes, the spring change was more special, which was characterized by the slowest temperature increase, the largest decrease of wind speed and the most significant increase in precipitation, the other seasons were more uniform in each factor. In the cyclical change, there was a significant quasi-3 period change in temperature and precipitation after removing the linear trend of significant global warming, and there was a complementary feature in the occurrence time domain.

  Diagnostic Analysis of a Strong Winter Cooling Process in Chongqing Dong Dandan, Zhang Jianping, Chen Quanliang, Deng Xia 2020, 36 (7):  105-111.  DOI: 10.11924/j.issn.1000-6850.casb18110060 Abstract + ( 324 )   HTML ( 0 )   PDF ( 5026KB )   ( 100 ) To fully understand the mechanism of strong winter cooling in Chongqing, this paper used the weather dynamic diagnosis method to analyze the weather system evolution characteristics, dynamic structural characteristics and water vapor conditions of a strong cooling weather process from January 22 to 29, 2018 in Chongqing, based on the conventional ground observation data, sounding data and the numerical model data. The results showed that: (1) from January 22 to 29, the cold air invaded Chongqing from the northeast path, and the daily average temperature generally decreased by at least 6℃ within 72 h; compared with the western region, the northeastern region with generally higher altitude was affected by the cold air earlier, so it had a large-scale temperature dropping earlier and the lowest temperature was generally lower than that of the western region, with rainy and snowy weather coming later; under the dynamic functions of high and low level jet stream and low vortex-shear line, a large-scale rain firstly appeared in eastern region with sufficient water vapor conditions; when the cold air returned to the western region, it caused continuous strong cooling and rain; (2) the low-pressure system and cold center in the west of Lake Baikal, the northeast cold vortex, high and low level jet stream and the middle-low level vortex-shear line were the key points to forecast the affected time and area for Chongqing strong cooling with rainy (snowy) weather.

  Temperature Field Distribution and Application of Three-span Solar Greenhouse Yin Qingzhen, Zhang Tiance, Gong Binbin, Qie Lijuan, Han Jianhui 2020, 36 (7):  112-121.  DOI: 10.11924/j.issn.1000-6850.casb19030052 Abstract + ( 626 )   HTML ( 1 )   PDF ( 3781KB )   ( 143 ) In view of the severe winter smog weather in the central and southern parts of Hebei Province and the solar greenhouse cannot fully utilize its proper thermal insulation function, the three-span solar greenhouse was designed and built. To verify its performance, the MATLAB software was used to fit the two-dimensional temperature field and image drawing of the three-span solar greenhouse. The results showed that the temperature of the three-span solar greenhouse at 00:23 was March 8> March 9> March 10. The temperature at 06:23 was the minimum of the three-span solar greenhouse of the day. The minimum temperature in three days was at 06:23 on March 10. The maximum temperature of the greenhouse was at 12:23 on March 8 of cloudy to overcast. The maximum temperature of the greenhouse was at 14:23 on March 9 of overcast to sunny. The maximum temperature of the greenhouse was from 12:23 to 14:23 on March 10 of sunny. The maximum temperature in the 3-day could reach 30℃. The temperature dropped faster from 16:23. From 9:23 to 10:23 on March 8 of cloudy to overcast and March 9 of overcast to sunny, the temperature rose from the upper middle of the north, middle and south of the greenhouse in turn and began to cool down from the lower part of the greenhouse at 16:23. From 09:23 to 10:23 on March 10 of sunny, the temperature rose from the upper middle of the south, middle and north of the greenhouse in turn and began to cool down from the lower part of the north, middle and south the greenhouse in turn at 16:23. The middle and lower part of the north side of the north of the greenhouse had the highest or lowest point of temperature. From March 8 to 10, 09:23 and 18:23 (15 to 20℃), 08:23 and 20:23 (10 to 15℃), the greenhouse temperature was basically the same. The soil temperature of the middle greenhouse was 22℃, the highest on the same day. The soil temperature of the north greenhouse was the lowest during the day. The soil temperature of the south greenhouse was the lowest during the night. The lowest soil temperature of the south greenhouse was 13℃. Light intensity was March 9< March 8< March 10. The thermophilic fruits and vegetables could be planted in the three-span solar greenhouse in mid-February, 25-30 days earlier than the single-film plastic greenhouse, while avoiding the high frequency of winter low temperature, cloudy and smoggy weather. The three-span solar greenhouse has obvious advantages.

  Huai’an Red Pepper Storage Quality Under Room Temperature: Preharvest Treatment Effect of Plant Growth Regulators Zhong Xiujuan, Wu Chuanwan, Gu Dalu, Yang Wenfei, Sun Yudong, Luo Dexu, Liang Shuanglin, Du Xiaofeng 2020, 36 (7):  122-127.  DOI: 10.11924/j.issn.1000-6850.casb18110106 Abstract + ( 355 )   HTML ( 5 )   PDF ( 1373KB )   ( 56 ) To study the effect of different plant growth regulators’ preharvest treatment on Huai’an red pepper storage quality under room temperature, the rate of weight loss, decay index, vitamin C content, malondialdehyde (MDA) content, polyphenol oxidase (PPO) and peroxidase (POD) activity were determined after 14 days treated with chitosan with different molecular weights, kelp polysaccharide (HDG), gibberellic acids(GAs) and salicylic acid (SA) at the period of red pepper turning red. The results showed that the treatment of low molecular weight chitosan (LWG) significantly delayed the weight loss. The treatment of LWG, HDG and SA significantly reduced the decay index and MDA content, and significantly improved vitamin C content, while LWG and SA significantly improved the activities of POD and PPO, and retarded senescence process and quality loss. The results suggest that the preharvest treatment with 0.5% LWG and 0.8 mmol/L SA could be a conducive technique to maintain Huai’an red pepper storage quality under room temperature.

  β-glucosidase from Stevia Leaves: Extraction and Characteristics Hou Menglan, Yang Yongheng, Zhang Ting, Sun Yuming, Zhang Yongxia, Yuan Hanyan, Huang Suzhen, Xu Xiaoyang 2020, 36 (7):  128-134.  DOI: 10.11924/j.issn.1000-6850.casb18110073 Abstract + ( 509 )   HTML ( 0 )   PDF ( 1520KB )   ( 151 ) The paper aims to study the role of stevia β-glucosidase in catabolism of steviol glycosides, and to lay a theoretical foundation for breeding of increasing steviol glycosides content by inhibiting its degradation in future. Stevia rebaudiana was used as test material in this study, and we firstly optimized the methods of extraction and determination of enzyme activity of β- glucosidase from stevia leaves, and then preliminarily analyzed the enzyme properties further. The results indicated that: the enzyme solution, which was extracted by 50 mmol/L phosphate buffer with pH 7.0, and added equivalent PVP during grinding, then salted out with 20%-40% saturation ammonium sulfate by the method of ammonium sulfate grade precipitation, had the highest enzyme activity; using pNPG as the substrate to determine enzyme activity, the best method was reacted at 37℃ for 60 min; and the results of enzyme property analysis showed that: stevia β-glucosidase possessed sound thermal stability and pH stability, its optimum temperature was 30℃, the optimum pH value was 7.0; but in 4℃, the enzyme activity gradually reduced, and was only 26.4% up to 26 d; among 9 common metal ions, Mn 2+ and Fe 2+ had significant activation effect on the enzyme, while Cu 2+ and Hg 2+ had obvious inhibition effect.

  Effect of Oil-water Mixed Solvent on the Antibacterial Effect of Essential Oils in Essential Oil Preparations Ma Yiyi, Wang Wencui, Huang Haiyan, Yao Lei 2020, 36 (7):  135-142.  DOI: 10.11924/j.issn.1000-6850.casb18110126 Abstract + ( 540 )   HTML ( 1 )   PDF ( 1428KB )   ( 51 ) To investigate the antibacterial effect of compound essential oil based on oil-water mixed solvent on settled bacteria in air, the antibacterial effect of the compound essential oil A and essential oil antibacterial preparations were studied, and the effect of oil-water mixed solvent on antibacterial effect of essential oil were determined. The inhibition effect of compound essential oil A was measured by plate sedimentation. Essential oil antibacterial preparations were made with the ratio of compound essential oil A and oil-water mixed solvent between 1:1 to 1:6, and five kinds of oil-water mixed solvents were chosen, such as PEG-40 hydrogenated castor oil, tween 80, dimethyl sulfoxide (DMSO), span 85 and double de-ethanol. Checkerboard dilution method was used to measure the inhibition effect of these preparations. And the results showed that, the bacteriostatic rate of compound essential oil A was larger than 80%, and the best bacteriostatic rate was 48.92% when the essential oil antibacterial preparation has exposed on flat for six hours. When PEG-40 in oil-water mixed solvent got the best solubilization effect, the ratio of essential oil, PEG-40 and double-de-ethanol was 1:2:2 when the concentration of compound essential oil was 1%, and was 1:3:3 when the concentration was 3%. PEG-40 showed no inhibition effect on settled bacteria in air, and the inhibition effect of double-de-ethanol and compound essential oil was additive. Based on the research above, when the plant essential oil is applied to industrial production, the type and proportion of the oil-water mixed solvent have certain actual effect on the essential oil product.

  The Rural Development Types and Rurality Evaluation at County-scale in Sichuan Chen Chunyan, Liu Yuanli, Li Mengying, Lin Zhengyu 2020, 36 (7):  143-150.  DOI: 10.11924/j.issn.1000-6850.casb18120092 Abstract + ( 636 )   HTML ( 2 )   PDF ( 2540KB )   ( 69 ) This paper aims to evaluate the rurality at county-scale in Sichuan, define the development types and rurality strength of the counties, and identify the spatial-temporal features in the balanced urban-rural development. Based on data during 2000 to 2016, we classified the rural development types and constructed the assessment indicators of rurality. The results showed that: (1) the pattern of counties in Sichuan was relatively stable, mainly the balanced development type and the agriculture-oriented type, with the complements of commercial service type and the industry-dominated type, and there were remarkable temporal and spatial differences in some types; (2) the county-scale rurality of Sichuan was mainly moderate and strong, the mean value of the rurality indicators presented a gradual downward trend, and county-scale rurality had significantly geographical agglomeration, with Chengdu plain as the center to increase gradually outward from low value to high value. The results have certain practical values in constructing new beautiful villages and promoting the development of urban-rural integration in Sichuan.

  Development of New Urbanization Based on Moderate Population Capacity:Five Cities in Ningxia Wang Chongling, Cheng Shujie, Zhu Zhiling, Wang Meimei 2020, 36 (7):  151-157.  DOI: 10.11924/j.issn.1000-6850.casb18110044 Abstract + ( 491 )   HTML ( 5 )   PDF ( 1588KB )   ( 171 ) The theoratical urbanization development levels of five cities are measured comprehensively by constructing the model of the carrying capacity of economy, land, water supply resources, construction land and ecological environment as well as the carrying capacity of population, then the results are compared with the actual urbanization development. The study indicates that: (1) the actual urbanization development of Yinchuan and Shizuishan are better than the theoretical one, the urban population potential index is large, therefore, the two cities are endowed with the ability to absorb non-native population; (2) the actual urbanization development of Wuzhong, Zhongwei and Guyuan are lower than the theoretical one, their urbanization development is low, and the population potential index is small, so the three cities do not possess the ability of absorbing non-native population. Based on this, corresponding countermeasures are put forward for new urbanization development in regions of different grades of population density: (1) for extremely densely populated and densely populated areas, on the one hand, radiative driving capability of the central city should be strengthened, and on the other hand, the guiding role of the government shall also be enhanced to promote the coordinated development of the citizenization process and the urban space; (2) for areas where population size is medium, the driving role of central cities should be strengthened while the pushing force of rural areas should be created to solve the worries of floating population during urbanization; (3) for sparsely populated and extremely sparesly populated areas, urbanization should be encouraged while urban-rural dual structure should be broken to promote the development of urbanization.

  Cultivating New Agricultural Management Entities: A Case of Shanghai Pudong New Area Zhang Jingyi, Ma Jia, Yang Huaiyu 2020, 36 (7):  158-164.  DOI: 10.11924/j.issn.1000-6850.casb18120024 Abstract + ( 500 )   HTML ( 3 )   PDF ( 1238KB )   ( 101 ) The ‘Rural Revitalization’ strategy was first proposed in the report of the 19 th CPC National Congress. One of the key points for rural revitalization is to cultivate new agricultural management entities. As the first batch of modern agricultural demonstration zones and national agricultural product quality and safety counties, Shanghai Pudong New Area has taken the lead in cultivating and developing family farms and farmers’ cooperatives in China, and has achieved remarkable results and played a good demonstration role in the development of national agriculture. Taking Pudong New Area as an example, we studied its demonstration reference for other similar regions in the country. Questionnaires and telephone interviews were conducted with relevant personnel from 25 towns in the area. At the same time, relevant documents and researches were read to analyze the development characteristics and existing problems of the new agricultural management entities. The results show that the development of Shanghai Pudong New Area has the characteristics of rapid growth, rapid branding and diversified development models. However, there are still problems in the scientific and technological personnel of agricultural management, agricultural ecological subsidies, agricultural credit insurance, and agricultural facilities. Therefore, it is necessary to introduce agricultural science and technology talents to establish a talent team; increase subsidies for agro-ecology, scientific and rational fertilization; vigorously promote agricultural insurance, diversify agricultural credit; break agricultural land restrictions and give full play to land use value.