Current issue

• 2018 Vol.34 No.16 Published:06 June 2018

  S-abscisic Acid Seed Dressing Under Low Temperature Stress: Effects on Physiological Indexes of Corn 2018, 34 (16):  1-5.  DOI: 10.11924/j.issn.1000-6850.casb18010097 Abstract + ( 1029 )   To investigate the physiological regulation of S-abscisic acid on maize under low temperature stress, the seeds of‘Dafeng 30’were used as the materials, and were coated with different concentrations of Sabscisic acid (0.2, 0.4, 0.6, 0.8, 1.0 mg/kg). After seed germination, the low temperature environment was simulated in the incubator. The physiological indexes, such as biological characteristics, root activity, chlorophyll content and leaf protective enzyme activity, were determined when the corns were at three leaves stage. The results showed that under low temperature stress, the growth, root activity, chlorophyll content and protective enzyme were significantly improved, while the content of peroxide malondialdehyde (MDA) in the membrane lipid was reduced. Meanwhile, the accumulations of reducing sugar and soluble protein were increased, and exhibited a tendency of first increasing and then reducing, with the increasing of S-abscisic acid. It indicates that the regulation of cold tolerance of corn has concentration effect to some extent, showing “Hormesis effect”.

  Salt Tolerance of Shandong Soybean Improved Varieties at Germination Stage 2018, 34 (16):  7-13.  DOI: 10.11924/j.issn.1000-6850.casb18020051 Abstract + ( 940 )   Salt damage is one of the important abiotic stresses, limiting plant growth and reducing crop yield and quality. Seeds of 9 Shandong soybean improved varieties were treated with different concentrations of NaCl solution (5, 10, 15 g/L) respectively, and their relative salt injury indexes were analyzed through calculating the seed germination number, relative germination rate, plant height, radicle length and the number of fibrous roots. The results showed that: with the increase of salt concentration, the seed germination number, plant height, and root number all had a decreasing trend, and there were significant differences among the varieties. Under the treatment of 5 g/L salt concentration, the radicle length of 3 varieties showed a rising trend, but other indexes decreased under all the three salt concentrations. Under the treatment of 5 g/L salt concentration, the 9 varieties were all high salt tolerant. Under the treatment of 10 g/L salt concentration, there were 5 hightolerance varieties; under 15 g/L salt concentration, there was one high salt-tolerant variety. Under different salt concentrations, relatively salt injury index had an extremely and significantly negative correlation with the germination rate, well reflecting the salt tolerance of soybean, and providing rich data references and parent materials for improving soybean germplasm resources and the utilization efficiency of saline soil.

  New Spring Potato Varieties with High Yield in Liangshan: Screening and Stability Study 2018, 34 (16):  14-21.  DOI: 10.11924/j.issn.1000-6850.casb17120007 Abstract + ( 913 )   To screen the spring potato varieties suitable for the ecological condition of Liangshan, Sichuan Academy of Agricultural Sciences and Xichang Agricultural Science Institute of Liangshan took Meigu, Zhaojue, Yuexi and Butuo as the demonstration sites to carry out multi-point experiment for the introduction and screening of spring potato varieties. The results showed that: the performance of‘Luoshuo’and ‘Chuanliangshu 1’in Meigu was outstanding; in Zhaojue, the new variety‘Qingshu 9’had a significant yield increase and could be popularized, and the variety‘Mila’could be planted with a moderate amount; in Yuexi, the planting area of‘Qingshu 9’could be increased, and proper amount of‘Mila’and‘Liangshu 17’could be planted; in Butuo, the planting area of‘Zhenshu 1’and‘Yunshu 107’could be increased, and the planting area of‘Mila’could be reduced properly. Thus, the varieties of spring potato suitable for different ecological regions in Liangshan are quite different, the introduction and selection of new varieties in the plateau mountainous areas could provide suitable potato varieties according to seasonal change and promote the development of potato industry in Liangshan of Sichuan.

  Establishment and Optimization of Tuber Regeneration System of Potato Varieties 2018, 34 (16):  22-28.  DOI: 10.11924/j.issn.1000-6850.casb18010167 Abstract + ( 931 )   In order to establish optimal potato tuber regeneration system. The microtubers and field potatoes of ‘Sharpdi’,‘Favorite’ and ‘Kexin No.1’ were used as the test material. The regeneration system was screened with a controlled variable method to obtain the optimal hormone concentration of the medium. And the comparison of adventitious buds differentiation rates of potato tubers from different sources was conducted. The result showed that the optimal callus induction mediums of ‘Sharpdi’ , ‘Favorite’ and ‘Kexin No.1’ were MS + 1 mg/L IAA + 1 mg/L 6-BA + 0.2 mg/L GA3 + 1 mg/L ZT, MS + 1 mg / L IAA + 1 mg / L 6-BA + 0.2 mg / L GA3 + 2 mg/L ZT and MS+1 mg/L IAA + 1 mg/L 6-BA + 0.5 mg/L GA3 + 2 mg/L ZT respectively. The optimal adventitious buds differentiation medium of ‘Sharpdi’ and ‘Favorite’ was MS + 1 mg/L IAA + 1 mg/L 6-BA + 0.5 mg/L GA3 + 2 mg/L ZT; while for ‘Kexin No.1’,the optimal differentiation medium was MS + 1 mg/L IAA + 1 mg/L 6-BA + 0.2 mg/L GA3 + 2 mg/L ZT. The differentiation rate of adventitious buds in microtuber was significantly higher than field potato.

  Curcuma zedoaria with Alcohol Extraction: Effects on Seed Germination and Seedling Growth of Mung Bean 2018, 34 (16):  29-34.  DOI: 10.11924/j.issn.1000-6850.casb17060108 Abstract + ( 899 )   To study the effects of Curcuma zedoaria with alcohol extraction on seed germination and seedling growth of mung bean, we conducted a soaking test of mung bean with different-concentration gradients of Curcuma zedoaria with alcohol extraction to determine whether the traditional Chinese medicine Curcuma zedoaria could be used as a biological plant growth hormone. We used the indoor hydroponics and germination on the petri dish paper. The content of chlorophyll was determined by pectro photometric method and the contents of soluble sugar were determined by anthrone colorimetry. The results showed that: the seed germination and seedling growth of mung bean were promoted by low concentration, were delayed by high concentration, and the delayed effect increased along with the increasing concentration. The germination index, root length, plant height, hypocotyl length, fresh weight, dry weight and root-shoot ratio increased first and then decreased, and the optimum concentration was 150 mg/L. The chlorophyll content and soluble sugar content of mung bean seedlings also increased first and then decreased, and the optimum concentration of organic matter was 300 mg/L. The results indicated that the low concentration of Curcuma zedoaria with alcohol extraction promoted the growth of the plant, but it was not conducive to the accumulation of organic matter. High concentration of Curcuma zedoaria with alcohol extraction delayed the growth of plant, but was beneficial to the accumulation of organic matter.

  Composition and Detection of High-molecular-weight Glutenin Subunit in Wheat: Research Progress 2018, 34 (16):  35-41.  DOI: 10.11924/j.issn.1000-6850.casb17120116 Abstract + ( 762 )   The composition of high-molecular-weight glutenin subunit (HMW-GS) of wheat is closely related to the quality of bread. To select the most suitable detection method of HMW-GS to meet the test requirements, the authors introduced the composition of HMW-GS in wheat and the progress on detecting the composition of HMW-GS with three methods, including sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDSPAGE), reverse phase high-performance liquid (RP-HPLC) and polymerase chain reaction (PCR). The authors discussed the advantages and disadvantages of the three methods, pointed out that SDS- PAGE and PCR methods were suitable for the HMW-GS detection in conventional breeding materials and cultivated wheat, and two-dimensional gel electrophoresis and RP-HPLC were suitable for the HMW-GS detection in the wheat with distant genetic material or the related species. At last, we proposed the application prospect of SDSPAGE and PCR in the molecular marker assisted breeding of wheat.

  Screening of Beet DAMD Primers and the Effects of Different Gel Systems on Polymorphism of Amplified Products 2018, 34 (16):  42-45.  DOI: 10.11924/j.issn.1000-6850.casb18020037 Abstract + ( 501 )   To select suitable for sugar beet varieties purity identification of DAMD primers, respectively using 12 different sugar beet varieties of 26 DAMD primers for amplification, and 6% respectively using polyacrylamide gel electrophoresis and 2% agarose gel electrophoresis, respectively, to test the amplification products.Results from 26 DAMD article 16 primers screened in clear primer amplification, this article 16 primers amplification out 139 bands, including polymorphism bands for 122, the percentage of polymorphic (87.7%), the 16 primers can be used as a sugar beet varieties purity and authenticity identification of core primers, also found that the polyacrylamide gel electrophoresis and agarose gel electrophoresis results difference is not big, but the agarose gel is easy to make, test the advantages of simple and does not apply to any potions, recommend beet DAMD amplification product detection using agarose gel electrophoresis.

  Combined Application of Cake Fertilizers Affects Dry Matter Accumulation and Plastid Pigment Content of Flue-cured Tobacco 2018, 34 (16):  46-50.  DOI: 10.11924/j.issn.1000-6850.casb17090116 Abstract + ( 595 )   The experiment aims to identify the application effects of cake fertilizers on growth, dry matter accumulation, plastid pigment of flue-cured tobacco. The results showed that all indexes of tobacco in different cake fertilizer treatments were better than those of CK, and cake fertilizer application significantly enhanced the growth potential of flue-cured tobacco, increased dry matter accumulation and plastid pigment content in tobacco leaves in pot experiments. The application of organic fertilizer could significantly improve the aroma premise material of flue-cured tobacco to increase the content of aroma substance. In addition, different cake fertilizer treatments showed different influences on the agronomic traits, dry matter accumulation, contents of nitrogen, phosphorus, and potassium, total chlorophyll and carotenoid content of flue-cured tobacco, and the best effects was found in combination 4 which could significantly increase the content of aroma material and be applied the cultivation and fertilization of flue-cured tobacco.

  Detain Dust Ability of Plants in Cold Region and Its Impact Factors 2018, 34 (16):  51-56.  DOI: 10.11924/j.issn.1000-6850.casb17110090 Abstract + ( 691 )   The paper aims to solve the problem of plant dust detain ability. The correlation between detain dust ability of 24 plants in cold region and its impact factors were studied based on multi-dimensional dust quantity/ unit (MDQu) comprehensive analysis method. The results showed that the structure of MDQu former with good consistency were logical, it could effectively reflect the practical detaining dust ability of plants in cold region. Plants with large amount of MDQu in cold region in winter including: Picea koraiensis, Pinus sylvestris var. mongolica, Ulmus pumila, Ovate catalpa and so on. There were significant correlations between detaining dust of plants in cold region in winter and the impact factors such as branch type, growth trend of branch, persistent tissue etc., but the correlations were different because of the specific direction.

  Crassulaceae Combinations Under Different Depths of Extensive Green Roofs in Beijing 2018, 34 (16):  57-64.  DOI: 10.11924/j.issn.1000-6850.casb17050021 Abstract + ( 687 )   This paper describes an experiment investigating the influence of plants diversity on green roof and the effect of substrate depths on plants survival, in order to select the vegetation types which can adapt to the climate of Beijing. The experiment was conducted under the real rooftop environment, the performances of 3 Crassulaceae combinations were tested on substrates of three different depths (7, 10, 15 cm). Plant survival, coverage, substrate moisture content, visual appearance and growth vigor were measured. It was concluded that deeper substrate promoted higher survival and coverage, better appearance and growth vigor, as well as higher substrate moisture content. By comparing the plant combinations and considering the performance of all indexes and plant diversity, it was found that No.2 (Sedum reflexum, Phedinum spurium‘Coccineum’, P. spurium‘Splendens’) > CK (S. lineare) > No.1 (S. sexangulare, S. acre, S. album‘Coral Carpet’). 15 cm substrate could provide a better growth environment for plants on the extensive green roofs, and No.2 was the best combination which could be widely applied in Beijing.

  Effects of Phosphorus Fertilizer Reduction on Yield, Quality and Soil Available Phosphorus of Greenhouse Tomato in Suburb of Beijing 2018, 34 (16):  65-69.  DOI: 10.11924/j.issn.1000-6850.casb17080115 Abstract + ( 669 )   To rectify the excessive application of phosphate fertilizer and achieve the goal of zero-growth of fertilizer, this study was conducted to evaluate the effects of phosphorus fertilizer reduction on yield and quality of greenhouse tomato and soil available phosphorus under different conditions, using a field test method. There were five treatments including conventional phosphorus fertilization, 30% reduction of phosphorus fertilizer, 60% reduction of phosphorus fertilizer, 100% reduction of phosphorus fertilizer and no fertilizer-applying. The results showed that soil available phosphorus content and the potassium content of plant were the highest under the conventional fertilizer condition. The N content of plant and fruit, the yield and the soluble solid content were the highest under the 30% phosphorus fertilizer reduction; the P content of plant and the K content of fruit were the highest under the 60% phosphorus fertilizer reduction; the Vc content of tomato was the highest under the 100% phosphorus fertilizer reduction. Therefore, the yield and quality of tomato were not decreased but slightly improved under suitable phosphorus fertilizer reduction.

  Callus Induction and Differentiation from Persea americana 2018, 34 (16):  70-77.  DOI: 10.11924/j.issn.1000-6850.casb17070095 Abstract + ( 652 )   The paper aims to examine the optimum combination of plant growth regulators (PGRs) and the type of explants on callus induction reactivity and the regenerative potentiality for suitable in vitro micropropagation of avocado‘Hass’. Using single factor and complete randomized block design via indirect organogenesis regeneration protocol, the present experiment was undertaken to explore the following: (1) the effect of 2,4-D/ NAA alone and different combinations of PGRs (BA+ 2,4-D/6-BA+ NAA) on callus induction via leaf explant from avocado‘Hass’; (2) the effect of different types of explants on callus induction from avocado‘Hass’; (3) the effect of 6-BA alone or combined with NAA for differentiation of callus. The results were: MS was used as the basic medium, (1) 2,4-D/NAA alone could induce callus with various degrees from leaf explant and there was a decrease in percentage of the extent of callus response and biomass with an increase in concentration of 2,4- D or NAA, the best frequency of callus response was obtained at 1.0 mg/L for 2,4- D/NAA, whose frequency was up to 45.3% and 20.2% respectively, but in terms of texture, callus induced by NAA was better; (2) the MS+1.0 mg/L NAA+1.0 mg/L 6-BA was the best medium for callus induction rate from leaf explant, and the highest rate reached 84%; (3) stem segment was the best kind of explant for callus formation and its frequency was up to 72.8% or higher, followed by petiole, however, the callus response was feeble when taking the leaf and stem apex as the explant. In conclusion, PGRs and the type of explants have a significantimpacton callus induction from avocado‘Hass’. The MS+1.0 mg/L NAA+1.0 mg/L 6-BA+30 g/L sucrose+7 g/L agar is the most appropriate medium for callus induction from avocado‘Hass’, and stem segment is the best kind of explant, but the callus shows no morphogenesis on any differentiation media.

  Phellamurin: Effect on the Dormancy of Phellodendron amurense Rupr. Seeds 徐硕 2018, 34 (16):  78-82.  DOI: 10.11924/j.issn.1000-6850.casb18020009 Abstract + ( 640 )   This study aims at studying the correlation between phellamurin and the environment temperature and seed dormancy degree, exploring the role of phellamurin in temperature signal mediation. High performance liquid chromatography (HPLC) is used to measure phellamurin content in leaves of Phellodendron amurense Rupr. at different locations and different years. The filter paper culture method was taken to measure the seed germination rate to determine the dormancy degree. Besides the temperature of sample sites were constantly monitored by temperature recorder. Through spraying phellamurin on the reproductive organs of Phellodendron amurense Rupr., the direct effect on seed dormancy degree by phellamurin was examined. Results showed that there was a difference of 5℃ in average temperature at flowering stages of Phellodendron amurense Rupr. within their growth areas, a difference of 54.46 mg/g in the average phellamurin contents in Phellodendron amurense Rupr. leaves, and a difference of 40.45% in the germination rates of seeds stratified for 30 days. By contrast, in different years, there was a difference of 1.16℃ in average temperature at flowering stages, a difference of 4.83 mg/g in the average phellamurin content, and a difference of 23.07% in the germination rate of seeds stratified for 30 days. By spraying phellamurin, the degree of seeds dormancy dramatically intensified and the germination rate decreased by 57.34%. The results suggested that the lower the environment temperature, the higher phellamurin content in leaves of Phellodendron amurense Rupr., and the deeper degree of seeds dormancy would be. The way of temperature regulating seeds dormancy degree of Phellodendron amurense Rupr. might be achieved by adjusting phellamurin content through some internal approaches.

  Pattern of Agroecosystem Water Use Efficiency and Its Formation Causes in China 徐宜民,,,,,陶健 and 陈爱国 2018, 34 (16):  83-91.  DOI: 10.11924/j.issn.1000-6850.casb17050097 Abstract + ( 639 )   Water use efficiency (WUE) is the basis in water balance research, and the review of spatialtemporal characteristics and drive mechanism of WUE could provide reference for co-ordination management of water supply and demand in different farmlands. The previous study showed that WUE in China had significant spatial-temporal difference, which was generally higher in the north than that in the south and higher in the east than that in the west. In time distribution, WUE in northern farmland showed an increasing trend and that in south China showed a decreasing trend. The precipitation, temperature and radiation indirect affected WUE through the influence on evapotranspiration and total primary productivity, plant structure and genetic factor mainly affected WUE thorough its influence on canopy, root water and carbon exchange capacity, the rational cultivation, irrigation and fertilization could increase WUE of precipitation, decrease the loss of irrigation water, improve the photosynthetic property, and then increase WUE. Considering the spatialtemporal characteristics and variation mechanism of WUE, increasing the water absorption characteristics of crop and reducing irrigation water loss are preferable ways to improve WUE in north China, while coordinating seasonal distribution of precipitation and reducing evapotranspiration and surface runoff are efficient approaches to promote WUE in south China.

  The Role and Mechanism of PAM in Phytoremediation of Heavy Metal Polluted Soil: A Review 2018, 34 (16):  92-99.  DOI: 10.11924/j.issn.1000-6850.casb17050116 Abstract + ( 768 )   As a kind of high-molecular polymer with fine performance, polyacrylamide (PAM) is widely applied to soil and water conservation and soil reclamation in agriculture in recent years. The potential of its application in phytoremediation of heavy metals polluted soils was analyzed based on summarizing the roles and mechanisms of PAM to heavy metals in soil via the literature research: (1) PAM and its modified products could absorb specific metal ions and alleviate the toxicity of heavy metals to plants, but its efficiency is affected by pH, temperature, etc. (2) PAM could improve physicochemical properties of soils and reduce the bioavailability of heavy metals through adsorption, chelation and complexation, so that improve the growing conditions of phytoremediation plants. Although acrylamide (AMD) as one of the degradation product of PAM exhibits neurotoxic effect, it could avoid the negative influence from the PAM degradation by adjusting the application way and adding degradation microorganism to maintain the health risk in a safe range. Thus, PAM is an environment-friendly accelerant for phytoremediation of heavy metal contaminated soils and its environmental risk could be controlled.

  Phenological Phase and Yield Components of Walnut in Wudu of Gansu: Variation Characteristics and Their Responses to Climate Factors 2018, 34 (16):  100-105.  DOI: 10.11924/j.issn.1000-6850.casb17040154 Abstract + ( 838 )   The paper aims to improve walnut yield and quality in Wudu, and to analyze the variation of the phenological phases and yield components of different walnut varieties under different meteorological conditions and their responses to climate. The authors took the“Million Acres Walnut Orchard”in Wudu, Longnan of Gansu as an experiment point, carried out continuous observation on the phenological phases and yield components of‘Wen185’and‘Qiangtele’from 2012 to 2013, analyzed the variation characteristics of phenological phases and yield components of the two varieties, and studied the relationship between the yield components and main climate factors combined with the corresponding meteorological data. The results showed that: (1) the phenological phases of different walnut varieties and years had big difference; (2) although the branch length of‘Wen185’in 2013 was obviously longer than that in 2012, the fruit diameter was smaller than that in 2012 owing to abnormally high temperature and less precipitation in early 2013; however, the growth of branch and fruit of‘Qiangtele’in 2013 was bigger than that in 2012 since its phenological phase was 20 days later than that of‘Wen185’, so earlier high temperature did not affect the growth of‘Qiangtele’; (3) the correlations between the growth of branch and fruit of‘Wen185’in 2012 and 2013 with temperature and precipitation were positive, while the correlation with sunshine hours was non-significantly negative, and the correlation with the minimum temperature was the most significant. In addition, the correlation between the growth of branch and fruit of‘Wen185’and temperature in 2013 was weaker than that in 2012, indicating that the abnormally high temperature was not favorable to the yield of‘Wen185’.

  Impact of Climate Change onPasture Production Potential in Inner Mongolia 2018, 34 (16):  106-114.  DOI: 10.11924/j.issn.1000-6850.casb17120012 Abstract + ( 579 )   To study the impact of climate change on pasture production potential is important for making full use of climate resources, tackling climate change and increasing the potential. Based on daily meteorological data of 30 meteorological stations in Inner Mongolia from 1960 to 2010 and the grassland observation data of 8 pasture observatories from 1983 to 2009, climate and pasture production potential characteristics of three types of pasture (meadow steppe, typical grassland and desert steppe) were analyzed by climate linear tendency model and Miami model. The results showed that grassland temperature increased and precipitation decreased in Inner Mongolia in recent 50 years. Climate warm drying trend was significant and worsening. The climate production potential of pasture gradually decreased from northeast to southwest as meadow grassland> typical grassland> desert grassland, the potential was 4490-6180, 4100-6000 and 420-5000 kg/hm2, respectively; the utilization rate of climate resources was meadow grassland> typical grassland> desert steppe, which was 39.2%-79.0%, 28.9%-66.3% and 21.2%-38.7%, respectively, still had a development potential. The effect of precipitation on the climate production potential of pasture was positive while the effect of temperature on that was different among different pasture types, temperature had positive effect on the potential of meadow grassland but negative effect on the potential of typical grassland and desert grassland in the southern region, and the synergistic effect of temperature and precipitation was observed on climate production potential of pasture in Inner Mongolia grassland. In general, precipitation is the main climatic factor restricting the climate production potential of pasture.

  Temperature and Humidity Prediction Models in Solar Greenhouse: Comparative Analysis Based on Stepwise Regression and BP Neural Network 2018, 34 (16):  115-125.  DOI: 10.11924/j.issn.1000-6850.casb17060118 Abstract + ( 748 )   To build a more accurate model for predicting temperature and humidity in solar greenhouse. The microclimatic observing experiment was carried out at Baodi District of Tianjin from 2011 to 2013 in winter (January, February and December). The temperature and humidity prediction models in geenhouse by using stepwise regression and BP neural network were established at 3 periods (0:00-8:00, 8:00-17:00, 17:00-23:00) of 3 kinds of weather types (sunny, cloudy, overcast). The results showed that: (1) the average accuracy rate of the absolute error of simulated and actual values less than 3℃ was 88%, and the root-mean-square error (REMS) was 2℃ under 9 conditions in greenhouse by using stepwise regression model of temperature, and the average accuracy rate of the absolute error of simulated and actual values less than 3℃ was 94%, and the root-mean-square error (RMES) was 1.6℃ under 9 conditions in greenhouse by using BP neural network model of temperature; the temperature prediction model established by BP neural network was more accurate and stable; (2) the average accuracy rate of the absolute error of simulated and actual values less than 6% was 81%, and the root-mean-square error (REMS) was 5.7% under 9 conditions in greenhouse by using stepwise regression model of relative humidity, and the average accuracy rate of the absolute error of simulated and actual values less than 6% was 80%, and the root-mean-square error (RMES) was 6.7% under 9 conditions in greenhouse by using BP neural network model of relative humidity. Both 2 models are not suitable for predicting the relative humidity of solar greenhouse at 8:00-17:00, while the humidity prediction model established by stepwise regression at 17:00-23:00 and 0:00-8:00 is more accurate and stable.hour,but the humidity prediction model established by stepwise regression at 17-23 hour and 0-8 hour is more accurate and stable.

  Sweetpotato Cultivation in Poor Dryland: By Herbicides Plus Plastic Film 2018, 34 (16):  126-130.  DOI: 10.11924/j.issn.1000-6850.casb18020027 Abstract + ( 772 )   To study the effect of sweetpotato cultivation by herbicides combined with plastic films, three herbicides, including 33% pendimethalin EC, 96% metolachlor EC and 50% acetochlor EC, are combined with mulching to control weed and increase yield in sweetpotato cultivation in poor dryland. The results showed that the average fresh tuber yield and dry yield of six treatments increased by 3.79 and 4 times, respectively, compared with CK, and the average stem leaf yield increased by 0.9 times. Among these treatments, the effect of 33% pendimethalin 4500 mL/hm2 with transparent film was the best; after 30 days and 45 days, the control efficacy on weeds were 87.33% and 85.33%; after 45 days and in the harvest time, the fresh mass efficacy reached 93.98% and 88.1% , respectively. The fresh tuber yield was 30300 kg/hm2, increased by 7 times compared with CK, the dry yield was 9999 kg/hm2, increased by 7.6 times and stem leaf yield was 25200 kg/hm2, increased by 2.7 times. In conclusion, sweetpotato planting benefit is low in poor dryland without taking agronomic measures, spraying herbicides combined with mulching before planting can effectively control weeds, improve soil temperature, promote seedling growth, fertilizer and water conservation, save labor, increase production, achieve the purpose of efficiency. The adoption of pendimethalin with transparent film should be widely promoted for its best effect.

  Predatory Mites: Control Efficacy Against Thrips at Tobacco Seedling-stage 王柱石 2018, 34 (16):  131-134.  DOI: 10.11924/j.issn.1000-6850.casb17050081 Abstract + ( 819 )   The paper aims to verify the control efficacy of predatory mites against thrips at tobacco seedlingstage. The authors investigated the occurrence and species of thrips and comparatively studied the control efficacy of release quantities, methods and carried microbial agents of different predatory mites in Zhongshu, Luxi, Yunnan. The results showed that: the main species of thrips was Frankliniella occidentalis (Pergande), followed by Thrips flavidulus (Bagnall), the thrips reached the highest peak in mid-April; the release of 100 mites Amblyseius cucumeris (Oudemans) per tray provided the best control efficacy among different release quantities, and the uniform broadcast method was significantly (P<0.05) more effective than placed with an open bag and CK; the control efficacy of predatory mites carried with Beauveria bassiana Vuillemin was the best, and the control efficacy of predatory mites carried with Metarhizium anisopliae Sorokin were parallel to that without microbial agent, whereas both were significantly more effective than CK (P<0.05).

  Apolygus lucorum in Tea Plantation: Control Index 张永亮,段永春 and 孙云先 2018, 34 (16):  135-138.  DOI: 10.11924/j.issn.1000-6850.casb17070039 Abstract + ( 591 )   To solve the problem that the spring tea is seriously damaged by Apolygus lucorum while we lack related control index, the field counting method of nymphs was studied according to the damage characteristics of A. lucorum nymphs. We conducted a field experiment to measure the economic loss rate of fresh tea leaves under different population densities of A. lucorum. Combining the economic loss rate of fresh tea leaves with the cost of control and fresh tea leaves benefit, the control index of A. lucorum could be determined with population density as a measure in Rizhao tea area. The results showed that: the activity range of A. lucorum in tea bushes was affected by the density of fresh leaves; the feeding behavior of A. lucorum usually occurred in a small range if the density of fresh leaves was relatively high; on the contrary, they would feed in a slightly large range; but no matter what kind of tea garden it was, the feeding activities of A. lucorum was within a circle whose horizontal diameter of the tea bushes was no more than 70 cm; the control index of A. lucorum should be 0.99 pests/1000 tips in the area to pick single bud, 1.08 pests/1000 tips in the area to pick one leaf and one bud and 1.48 pests/1000 tips in the area of picking one leaf and two buds. The control index with the population density of A. lucorum as a measure has high accuracy. It provides a scientific basis for the tea gardens whose control expenses and fresh tea leaves income are similar with Rizhao’s. However, A. lucorum nymphs are generally in an aggregate distribution, always live in seclusion and newly hatched nymphs are too small to be found easily, we should take multiple observation counting methods to determine the population density.

  Preliminary Disease Investigation on Panax japonicus var. major in Northwest Yunnan 和琼姬,苏泽春,程远辉,康平德,杨丽云,李兆光 and 王泽清 2018, 34 (16):  139-143.  DOI: 10.11924/j.issn.1000-6850.casb17110059 Abstract + ( 551 )   The paper aims to ensure a healthy and sustainable development of Panax japonicus var. major industry in northwest Yunnan. In 2017, we investigated the diseases in 5 contiguous P. japonicus var. major planting bases during the disease peak time using a five-point sampling investigation method, counted the number of diseased plant, and calculated the morbidity and the disease index. There were 3 kinds of main diseases of P. japonicus var. major in northwest Yunnan, including round spot disease, black spot and rust disease. Other diseases also occurred in varying degrees, such as botrytis cinerea, powdery mildew, anthracnose and phytophthora blight. The incidence rate under proper farming operation was relatively lower than that under the intercropping with rhizoma paridis or in observation points with widespread weeds. The most serious diseases of P. japonicus var. major production were round spot disease, black spot and rust disease. Therefore, using proper farming operation, such as designing a shelter and building a cultivation garden in high ground with well- ventilation and drainage condition, could greatly reduce the occurrence degree of the diseases.

  Processing Techniques Affecting the Physical Properties of Instant Foxtail Millet Porridge 2018, 34 (16):  144-150.  DOI: 10.11924/j.issn.1000-6850.casb17050083 Abstract + ( 661 )   Instant porridge is becoming more popular nowadays with the accelerated pace of life. However, to improve the physical quality of instant porridge products is still the key point. We made instant millet porridge with foxtail millet as raw material, with high pressure and freeze drying as the main methods. Then, we investigated the effects of processing factors: material-water ratio, processing time and drying temperature on rehydration qualities and texture properties of the instant millet porridge using response surface methodology (RSM). The results showed that water absorption index (WAI), water solubility index (WSI), springiness, gumminess, chewiness were fitted the model of quadratic due to their high R2 and lack-of-fit. In the results, material- water ratio had no significant effect on springiness of quality of instant millet porridge, while processing time only had influences on the texture properties of rehydration millet porridge, and drying temperature had significant effect on WSI and gumminess. In addition, rehydration time and foxtail millet porridge moisture content had a negative correlation.

  Separation and Identification of Rot Pathogens in Salted Egg Brine 2018, 34 (16):  151-156.  DOI: 10.11924/j.issn.1000-6850.casb17040109 Abstract + ( 608 )   Salted egg processing factory is prone to have pickled egg corruption in high temperature season, the purpose of this study is to explore salt-tolerant bacterial group in the salted egg brine, and to identify bacterial strains leading to pickled egg corruption. Agar plate dilution method and egg pickled disproof experiment were used to screen out the bacterial strains, and the strains were identified by morphologyobservation, physiological and biochemical detection and molecular biological analysis. The results showed that 20 strains of salt-tolerant bacteria were isolated from the corrupted salted egg brine, of which 5 strains made the corruption rate of salted eggs exceeded 45%. 16S rDNA sequence analysis found that 3 strains belonged to Staphylococcus, 1 strain was Proteus, and 18S rDNA sequence analysis identified 1 strain belonging to Plectosphaerella. Based on the above results and the growth characteristics of the 5 strains, it is concluded that the main rot strains are from Staphylococcus, Proteus and Plectosphaerella.

  Convergence Development of Rural Primary, Secondary and Tertiary Industries: Review and Outlook 安 岩 and 侯丽薇 2018, 34 (16):  157-164.  DOI: 10.11924/j.issn.1000-6850.casb17090035 Abstract + ( 1067 )   The paper aims to systematically study the necessity, connotation, characteristics, motivation, mechanism, mode, path and problems of the convergence development of primary, secondary and tertiary industries in rural, and promote the maturity and perfection of related research.In this paper, the methods are literature and comparative analysis, use this methods to sum up the research results about the convergence development of primary, secondary and tertiary industries in rural in the academic circles, the paper summarizes the necessity of convergence development of primary, secondary and tertiary industries in rural, analyzes the connotation, characteristics and the motivation, mechanism, introduces the mode and path, points out the problems, and sums up the policy suggestions for further development. The results show that the domestic research focus on the connotation and mode as well as problems and countermeasures and other aspects, mainly based on field research, experience and qualitative analysis, but for the deep analysis on convergence development of primary, secondary and tertiary industries in rural is rare; the future research can focus on micro actors: in-depth analysis of the fusion and reason of behavior from farmers, enterprises, intermediary organizations and government; and to explore the mechanism of interest linking among farmers, enterprises, intermediary organizations and other integration subjects.