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    01 September 2019, Volume 52 Issue 17
    CROP GENETICS & BREEDING·GERMPLASM RESOURCES·MOLECULAR GENETICS
    Evaluation of Rice Germplasms for Grain Resistant Starch Content and Its Environmental Stability
    ZHANG ChunLong, Channarong PHONGSAI, ZHANG JiangLi, YUYang, SU YaoHua, YANG Mi, GAO Liang, PU ShiHuang, LI Juan, JIN ShouLin, TAN XueLin, WEN JianCheng
    Scientia Agricultura Sinica. 2019, 52(17):  2921-2928.  doi:10.3864/j.issn.0578-1752.2019.17.001
    Abstract ( 738 )   HTML ( 104 )   PDF (576KB) ( 503 )   Save
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    【Objective】 It is beneficial for improving the health of chronic patients to eat high resistant starch (RS) content rice, but variety with high grain RS content is still very rare. Evaluations of rice germplasms for grain RS contents and its environmental stability were carried out in this study, and the results could provide a reference for the discovery of rice germplasm resources with high RS contents and its production. 【Method】 Grain RS contents in rice germplasms were detected by the Megazyme method, and used the PAST software to complete the frequency distribution of these contents. The environmental stability of rice RS contents were tested by planting at multiple locations within one year, and its variance analysis were performed with DPS software. Grain amylase contents were tested according to the national standard GB/T15683-2008. 【Result】 The initial evaluations on RS contents of 1206 rice germplasms demonstrated that for most these rice with RS content were very low, and about 87.6% of the rice were less than 2.5%, only about 0.2% were higher than 10%. There was a significant positive correlation between rice RS and amylose content, but high RS variety was not discovered in high amylose germplasms. However, three varieties with RS content higher than 10% were screened in low amylose content germplasms, and one of them was a good quality soft rice variety Diangu2, which has RS and amylose content of 10.12% and 12.3%, respectively. It carried out regional tests for eighteen varieties with different RS contents planting at three very differ environmental conditions. The result of environmental stability analysis indicated that the contents of thirteen varieties were affected by differences in planting area, of the others were affected. Totally, the contents were affected by genotype, planting environment and genotype-by-environment interactions. 【Conclusion】 In this research, most rice resources have low RS content, and also detected a significant positive correlation between rice grain RS and amylase content. Therefore, it is possible to develop rice variety with high RS starch and good taste, according the high RS varieties were identified in low amylose content germplasms. The RS content was mainly affected by genotype, so the varieties with high RS contents were high at different environments, and the lows’ were still low. Then, the varieties with high RS content can grow in its suitable areas to produce rice, and the contents could not be significantly affected.

    CROP GENETICS & BREEDING·GERMPLASM RESOURCES·MOLECULAR GENETICS
    Evaluation of Genotype Differences of Cold Tolerance of Sweet Potato Seedlings by Subordinate Function Value Analysis
    XU Shu,LI Ling,ZHANG SiMeng,CAO RuXia,CHEN LingLing,CUI Peng,Lü ZunFu,WU LieHong,LU GuoQuan
    Scientia Agricultura Sinica. 2019, 52(17):  2929-2938.  doi:10.3864/j.issn.0578-1752.2019.17.002
    Abstract ( 428 )   HTML ( 30 )   PDF (1248KB) ( 327 )   Save
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    【Objective】 It is of great significance to explore the low temperature tolerance mechanism of sweet potato seedlings and identify the key factors affecting the low temperature tolerance of the seedlings for evaluation and screening of cold tolerance genetic resources of the seedlings and research on the mechanism of low temperature tolerance of sweet potatoes.【Method】 In order to investigate the cold tolerance of different varieties of sweet potato seedlings, 30 varieties of sweet potato seedlings were selected and tested under low temperature conditions of 4℃ in this study, their physiological indexes and antioxidant enzyme indexes were measured so as to observe the effects of low temperature stress on physiological characteristics of sweet potato seedlings. The low temperature tolerant sweet potato varieties were screened by the subordinate function analysis of the physiological characteristics of sweet potato seedlings.【Result】 Great difference of the physiological indexes of 30 different genotypes of sweet potato seedlings were found under low temperature stress. After low temperature stress the relative electrical conductivity and proline contents of all sweet potato seedlings were increased to different extents. The relative conductivity of Sushu 16 changed the most, up to 40.16%, and the most increased proline content was Liaoshu 15 up to 3.66 μg·g -1 FW; malondialdehyde (MDA), superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), Ascorbate peroxidase (APX) showed an upward trend; among the 30 varieties of potato seedlings, the most significant change in MDA content was Suyu 303; the SOD activity of all sweet potato seedlings increased, and the most variable SOD activity was Yushu 17. The change before and after stress was as high as 27.59 U·g -1 FW, but Ningzishu 1, Shangxuzi 1 and Ziluolan seedlings were in a state of wilting and death, and the change of SOD activity showed a negative value; the POD activity of all potato seedlings showed an upward trend. The highest change in POD activity was Gan 10-20, up to 29.21 U·(g·min) -1, and the change of POD content in Ziluolan was negative; the highest increase in CAT activity was Hongxiangjiao; The change of APX activity showed an upward trend, and the potato 25, Hongxiangjiao and Longzishu 6 greatest change, Pu 32, Shangshu 8, Ziluolan the minimum change; proline content is increased up to Liao 15, up to 3.66, It is 1.5 times that of Shangxuzi 1. Correlation analysis of physiological indexes of sweet potato seedlings showed that relative conductivity and MDA content were negatively correlated with cold tolerance of sweet potato seedlings. SOD, POD, CAT and APX activities were positively correlated with cold tolerance of sweet potato seedlings, proline content and cold tolerance of sweet potato seedlings. Sexuality is positively correlated.【Conclusion】 Comprehensive conductivity and antioxidant enzymes and proline indicators, according to membership function analysis. Different varieties of sweet potatoes were different in low temperature resistance. At the temperature of 4℃, the order of low temperature resistance of all sweet potatoes was: Longshu515>Gan10-20>Nanshu010>Hongxiangjiao>Guangshu87>Sushu8>Yushu17>Longzishu6>Yanshu25>Zheshu13>Yizhi138>Sweet potato 166-7>Qingzishu2>Xushu55-2>Liaoshu19>Liaoshu15>Longshu14>Xushu22>Shangshu19>Pushu32>Ningzishu2>Longshu9>Shangshu8>Xuzishu8>Hongdong>Sushu16>Taiwanyingou>Shangxuzishu1>Suyu303>Ziluolan.

    TILLAGE & CULTIVATION·PHYSIOLOGY & BIOCHEMISTRY·AGRICULTURE INFORMATION TECHNOLOGY
    Photosynthetic Response Characteristics of Maize Under Drip Irrigation Based on Machine Learning
    LIU HuiFang,HE Zheng,JIA Biao,LIU Zhi,LI ZhenZhou,FU JiangPeng,MU RuiRui,KANG JianHong
    Scientia Agricultura Sinica. 2019, 52(17):  2939-2950.  doi:10.3864/j.issn.0578-1752.2019.17.003
    Abstract ( 492 )   HTML ( 44 )   PDF (615KB) ( 241 )   Save
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    【Objective】 This study proposed an optimized grid search method based on machine learning to solve the problem of model parameters of the photosynthetic light-response curve for drip-irrigated maize, which was often hard to determine and possesses low precision, so as to provide new ideas for photosynthetic characteristics and mechanisms of drip-irrigated maize in Ningxia. 【Method】 The experiment was conducted in 2017 and 2018 with the maize cultivar TC19, which was widely cultivated in Ningxia. Six levels of potassium application (0 (K0), 90 kg·hm -2 (K1), 180 kg·hm -2 (K2), 270 kg·hm -2 (K3), 360 kg·hm -2 (K4), 450 kg·hm -2 (K5)) were set, and the portable gas exchange system (Li-6400XT) was used to measure the light-response curves of maize under different potassium levels at silking stage. The grid search method based on machine learning and nonlinear regression analysis was used to revise the light response curve based on the right angle and hyperbolic correction model. The correlation coefficient (R 2), root-mean-square error (RMSE) and mean absolute error (MAE) were used to evaluate the accuracy of the model. 【Result】 The results showed that the photosynthetic parameters (Pn), transpiration rate (Tr) and stomatal conductance (Gs) of maize leaves increased first and then decreased with the increase of potassium application rate. The results of fitting evaluation indicated that the calculation results of machine learning method under K0 and K1 were better than the traditional method, in which R 2 was greater than 0.991, RMSE and MAE were less than 1.487 and 1.350, respectively. The two methods have similar fitting effect under K2-K5, while R 2was greater than 0.993, RMSE and MAE was less than 0.952 and 0.860, respectively. The result of optical response characteristic parameter calculation by using the optimum fitting method (grid search method) showed that the trends of α, Pnmax, Rd, LSP and LCP were similar to their photosynthetic parameters. When the potassium application rate was 360 kg·hm -2 (K4), the light response characteristic parameters reached the maximum value, however, the light suppression phenomenon occurred at 450 kg·hm -2 (K5). 【Conclusion】 The grid search method based on machine learning could accurately fit the photo-response characteristics of drip-irrigated maize in Ningxia, and the photosynthetic performance of maize was the best when the potassium application rate was 360 kg·hm -2.

    TILLAGE & CULTIVATION·PHYSIOLOGY & BIOCHEMISTRY·AGRICULTURE INFORMATION TECHNOLOGY
    Crop Identification Based on TWDTW Method and Time Series GF-1 WFV
    QIU PengXun, WANG XiaoQin, CHA MingXing, LI YaLi
    Scientia Agricultura Sinica. 2019, 52(17):  2951-2961.  doi:10.3864/j.issn.0578-1752.2019.17.004
    Abstract ( 650 )   HTML ( 22 )   PDF (3836KB) ( 510 )   Save
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    【Objective】 Yanqi Basin is an important production base of characteristic agricultural products in Xinjiang, and the planting structure of crops is complicated. In this study, the time series remote sensing data were used to classify and identify crops in the study area, so as to obtain the spatial distribution of different crops and their planting areas, which were the important basis for government sectors to formulate grain policies and economic plans. At the same time, the applicability of time-weighted dynamic time warping (TWDTW ) method in crop classification and the application potential of GF-1 WFV in agriculture were also discussed.【Method】 The normalized vegetation index (NDVI), calculated from the 2018 time series GF-1 WFV data set in Yanqi Basin, Xinjiang, was used to study the crops recognition based on TWDTW method. Sample points of different crops were collected to form standard sequence of NDVI for each crop. The TWDTW similarity matching algorithm was used to calculate the similarity distance between each pixel to be classified and the standard sequence of different crops. The smaller the distance was, the higher the similarity was. The similarity was used to determine the crop type of the pixel, and the final classification result was obtained. At the same time, the classification rules of decision tree were established according to the NDVI curve of time series, and the classification result was obtained by manually setting the classification threshold, and compared with that of the TWDTW method. 【Result】 The classification results of the two methods were very consistent. Peppers were the most widely planted and the wheat was mainly distributed in the northern part of the Yanqi Basin and the 21st Division of the Second Agricultural Division. The distributions of tomato and sugar beet were relatively sporadic. Among the results of planting area, pepper had the largest planting area, followed by tomato, wheat and sugar beet. The accuracy of the classification results of the TWDTW and decision tree methods was verified by the field sample points: The overall accuracy of them were 89.58% and 90.97%, respectively, and the kappa index of them were 0.804 and 0.830, respectively. The classification accuracy of the TWDTW method was slightly higher than that of the decision tree method. 【Conclusion】 Compared with the decision tree classification method, the classification accuracy of the TWDTW method was slightly improved, the classification result was more objective and reliable. The algorithm of TWDTW method was not limited by geographical factors and had strong flexibility and applicability. The experimental results showed that using TWDTW algorithm to identify crops based on the GF-1 WFV data set of dense temporal phase could get better classification results, and it had great application and popularization value in agricultural field.

    PLANT PROTECTION
    Resistance Evaluation of Some Commonly Used Maize Germplasm Resources to Fusarium Diseases in China
    QU Qing,LI LiNa,LIU Jun,WANG ShaoXin,CAO ZhiYan,DONG JinGao
    Scientia Agricultura Sinica. 2019, 52(17):  2962-2971.  doi:10.3864/j.issn.0578-1752.2019.17.005
    Abstract ( 595 )   HTML ( 20 )   PDF (4792KB) ( 473 )   Save
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    【Objective】 Maize ear rot, stalk rot and sheath rot are the three common Fusarium diseases in maize producing areas in China, and there is a trend of serious mixing occurrence in recent years. The main pathogens of the three major diseases are F. verticillioides, F. graminearum and F. proliferatum. Planting resistant varieties is the most economical and effective method to control this kind of diseases. The objective of this study is to screen out the maize resistant germplasms to ear rot, stalk rot and sheath rot, and to provide references for scientific breeding and rational layout of maize varieties.【Method】 Sixteen common inbred lines of maize including B73, B37, Zheng 58, Chang 7-2, Qi 319 and so on were selected to inoculate F. verticillioides, F. graminearum, and F. proliferatum on maize ears, stalks and sheaths, respectively. The suspension spores of F. verticillioides were injected into healthy maize ears along the filament channel with a continuous syringe at silk stage. The stem of the first aboveground segment of healthy maize was pinned and then injected with the suspension spores of F. graminearum. The suspension spores of F. proliferatum were injected into the sheath of the aboveground 2-5 internodes along the base of healthy maize sheath. Sterile water was used as control. In 2016 and 2018, experiments were conducted in fields to evaluate the disease index of ear rot, sheath rot and the lesion areas of stalk rot, so as to evaluate the resistance level to the ear rot, stalk rot and sheath rot.【Result】 The tested inbred lines Ji 853, OH43 and X178 were moderate resistance to ear rot, 13 of the tested inbred lines such as B73, B37, PH6WC, Ye 478, Zheng 58, 9058, Chang 7-2, Xun 928, Mo17, A619, PH4CV, Qi 319 and 13-1077 were sensitivity or high sensitivity to ear rot; 8 of the tested inbred lines including Qi 319, PH4CV, Mo17, 9058, B37, B73, Chang 7-2 and 13-1077 were moderate resistance and high resistance to stalk rot, 7 of the tested inbred lines such as Zheng 58, Ye 478, PH6WC, Xun 928, Ji 853, A619 and OH43 were sensitivity or high sensitivity to stalk rot; 15 of the tested inbred lines such as B73, B37, Zheng 58, Ye 478, PH6WC, 9058, Chang 7-2, Ji 853, Xun 928, Mo17, A619, PH4CV, OH43, Qi 319 and 13-1077 were moderate resistance or resistance to sheath rot. According to the population of 16 inbred lines, Reid group was susceptible to ear rot. Lancaster group and Tangsipingtou group were resistant to sheath rot. The resistant levels of other groups to Fusarium diseases dispersed to a large extent, and there was no obvious regularity.【Conclusion】 The tested inbred lines Ji 853 and OH43 showed moderate resistance or resistance to sheath rot and ear rot, 8 of the tested inbred lines including Qi 319, PH4CV, Mo17, 9058, B37, B73, Chang 7-2 and 13-1077 showed moderate resistance, resistance or high resistance to sheath rot and stalk rot, but the materials with good resistance to all three diseases had not yet been screened, and other germplasm resources needed to be further screened.

    Inhibitory Effect of Dimethyl Disulfide from Burkholderia pyrrocinia WY6-5 on Aspergillus flavus and Aflatoxins in Peanuts During Storage Period
    GONG AnDong,DONG FeiYan,WU NanNan,KONG XianWei,ZHAO Qian,YAN JianLi,Cheelo DIMUNA
    Scientia Agricultura Sinica. 2019, 52(17):  2972-2982.  doi:10.3864/j.issn.0578-1752.2019.17.006
    Abstract ( 424 )   HTML ( 21 )   PDF (1791KB) ( 340 )   Save
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    【Objective】The objective of this study is to verify the antifungal effect of Burkholderia pyrrocinia WY6-5, evaluate its control efficacy against Aspergillus flavus and aflatoxins in peanuts during storage period, analyze the inhibitory mechanism, identify antifungal volatiles and detect the minimal inhibitory concentration to A. flavus, so as to provide novel strategies for the prevention and control of fungal diseases and mycotoxin during storage period.【Method】Face-to-face dual cultural test was conducted to analyze the antifungal activity of volatiles from WY6-5. Active charcoal as volatile adsorbent was added into the tests to verify the antifungal activity of volatiles. Dimethyl disulfide (DMDS) emitted form strain WY6-5 was challenged with peanut kernels inoculated with A. flavus conidia in sealed airspace without physical contact. A. flavus cells on peanut coat were collected, fixed in osmic acid, and analyzed through scanning electron microscope (SEM). Transmission electron microscope (TEM) was used to test the inner structure of A. flavus cell affected by volatiles from WY6-5. The commercial DMDS was purchased, serially diluted, and co-cultured with A. flavus conidia and mycelia to detect the minimal inhibitory concentration, respectively.【Result】B. pyrrocinia WY6-5 isolated from rhizosphere soil of tea plants could produce volatile DMDS, prevent the growth of A. flavus mycelia, the inhibition rate was over 95%. Additionally, under the condition of high water activity (aw), WY6-5 could also inhibit the A. flavus infection and aflatoxins production in peanuts during storage period. In peanuts of control treatment, the disease incidence was 100%, and the total concentration of aflatoxins was 399.32 μg?kg -1 (aw 0.859) and 3 143.19 μg?kg -1 (aw 0.923), respectively. When WY6-5 was added in the treatment, the disease incidence decreased to 2% (aw 0.859) and 21% (aw 0.923), respectively. The concentration of aflatoxins decreased to 4.86 μg?kg -1 (aw 0.859) and 121.37 μg?kg -1 (aw 0.923), respectively. The inhibition rate of WY6-5 against aflatoxins contamination was 98.78% and 96.14% compared to the control treatment. SEM analysis proved that DMDS from WY6-5 inhibited the germination of A. flavus conidia. TEM analysis further proved that the inner cell structures of A. flavus conidia were not severely damaged by volatiles. Volatile DMDS showed great antifungal activity. The minimal inhibitory concentration against mycelia growth was 100 μL?L -1(compound volume/airspace volume). The minimal inhibitory concentration against conidia germination was 50 μL?L -1(compound volume/airspace volume). 【Conclusion】 B. pyrrocinia WY6-5 can produce valid antifungal volatile DMDS, which can completely inhibit the mycelia growth and conidia germination of A. flavus at low concentration, and greatly prevent the development of A. flavus disease and aflatoxins contamination in peanuts during storage period. WY6-5 and the produced DMDS provide novel bio-active agents for fungal diseases control and mycotoxins during storage period.

    SOIL & FERTILIZER·WATER-SAVING IRRIGATION·AGROECOLOGY & ENVIRONMENT
    Effect of Manure Application on Nitrogen Use Efficiency of Crops in China: A Meta-Analysis
    REN KeYu,DUAN YingHua,XU MingGang,ZHANG XuBo
    Scientia Agricultura Sinica. 2019, 52(17):  2983-2996.  doi:10.3864/j.issn.0578-1752.2019.17.007
    Abstract ( 727 )   HTML ( 38 )   PDF (727KB) ( 687 )   Save
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    【Objective】 Combined chemical fertilizers with manure is one of the important approaches to improve the nitrogen use efficiency (NUE) of crops. Nowadays, rare studies focused on systematic comparison and analysis of combine chemical fertilizers with manure on nitrogen use efficiency in different regions of China. In addition, NUE is affected by many factors, such as nitrogen application amount, soil properties and the climatic conditions and even most of them are in the specific regions. Therefore, this study was carried out to explore the effects of chemical fertilizers combined with manure on NUE, and quantify the response of NUE to manure application in different soils and climatic regions, so as to give the guidance on sustaining regional agricultural development and provide an important theoretical basis for reducing fertilizer application. 【Method】 This study was conducted based on a database of NUE including 412 sets on NPKM vs. NPK, which were collected from 110 published articles with wheat, maize and rice. We analyzed the differences of NUE between the treatment of NPK and NPKM in five regions in China by Meta-analysis, and quantified the contribution of main controlling factors on positive manure affects by Random Forest analysis. 【Result】 Compared with NPK, NPKM treatment increased the NUE by 3.6%. NPKM treatment significantly increased the NUE of crops in all regions except the Northeast China. The highest enhancement was found at Northwestern China, followed by Northern China, Southern Region and Eastern China. Soil organic matter, pH, available potassium and total nitrogen were the main factors affecting the “positive effect” of manure on NUE. The increment of NUE by manure application was higher in the soils with lower organic matter content than that in the soils with high organic matter content. The increase of NUE in alkaline soils with manure applied was 1.3 and 1.8 times higher than those on neutral and acidic soils, respectively. The improvement of NUE by manure application varied among climate regions: temperate continental climate zone>temperate monsoon climate zone>subtropical monsoon climate zone. 【Conclusion】 The application of manure could significantly increase the NUE of crops, especially in northwestern areas with low organic matter content and less rainfall.

    A Novel Method for Quantitating Water and Fertilizer Coupling Types and Its Application in Optimizing Water and Nitrogen Combination in Winter Wheat in the North China Plain
    ZHANG JingTing,Lü LiHua,ZHANG LiHua,DONG ZhiQiang,YAO YanRong,YAO HaiPo,SHEN HaiPing,JIA XiuLing
    Scientia Agricultura Sinica. 2019, 52(17):  2997-3007.  doi:10.3864/j.issn.0578-1752.2019.17.008
    Abstract ( 375 )   HTML ( 16 )   PDF (585KB) ( 333 )   Save
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    【Objective】 A novel method for distinguishing quantitatively irrigation and fertilizer coupling types was introduced, and basing on this method, irrigation and nitrogen combination in winter wheat on North China Plain was to be optimized. The aim of the study was to have a greater understanding of coupling effect of water and fertilizer, and to provide theoretical and practical basis for promoting water and fertilizer synergetic management in crop production. 【Method】 The results showed that the difference between the true value and the theoretical value of crop relative yield was statistically significant (P<0.05) or not was considered as the critical criterion for distinguishing the coupling type of a specific water-fertilizer combination. The two-factor split plot experiment was persistently carried out in the North China Plain in Hebei province during ten successive winter wheat growing seasons (2016-2016). In this experiment, the two irrigation treatments were the main plots, irrigation one time (75 mm in jointing stage, W1) and two times (75 mm in jointing and flowering stage respectively, W2) during wheat growing season, and five N rates were the subplots, consisting of 0 (N0), 60 (N60), 120 (N120), 180 (N180), and 240 (N240) kg·hm -2, respectively. The coupling types of different water-nitrogen combinations and their inter-annual variation characteristics were explored to determine the optimized water-nitrogen combination in winter wheat growing seasons.【Result】 When the true value of the crop relative yield of a water-fertilizer combination was statistically higher than its theoretical value, the water and fertilizer coupling type of this combination was “synergism” (water and fertilizer promote mutually). When the true value was significantly smaller than the theoretical value, the water and fertilizer coupling type was “antagonism” (water and fertilizer restrict mutually). When there was no significant difference between the true value and the theoretical value, the water and fertilizer coupling type of the combination was “additivity” (water and fertilizer no interaction). The water-nitrogen coupling type and inter-annual variation characteristics of the W2Nx combinations in winter wheat were significantly affected by nitrogen application rate. Generally, the water-nitrogen coupling type of W2N60 was antagonism basing on the average yield of winter wheat in the 10 years. To be specific, for the W2N60, water and nitrogen antagonized mutually in the first two experimental years, in the 3rd year the relationship between water and nitrogen changed into collaboration until the 5th experimental year, and the water-nitrogen coupling type of the combination was antagonism in the 6th to 10th year. The water-nitrogen coupling type of W2N120 was additivity in the 1st to 4th year, and then turned into synergism in the 5th to 10th experimental year. The coupling type of W2N180 and W2N240, in which nitrogen application exceed 120 kg·hm -2, was additivity in each year in the experiment. 【Conclusion】 It is of great feasibility to identify quantitatively the coupling type of a specific water and fertilizer combination based on the significance of the difference between the actual value and the theoretical value of the crop relative yield. Under the combination of W2N120, water and nitrogen promoted yield increase synergistically for a long time. Therefore, maintaining the annual grain yield of 8.5 t·hm -2 or so, W2N120 should be recommended as an optimal combination of water and nitrogen for winter wheat in the northern part of the Huang-Huai Plain over a certain period of time.

    HORTICULTURE
    Influence of Anti-transpirant on Photosynthesis Characteristic and Qualities of Wines in Hot Climate
    LI WanPing,LIU Min,WANG JieXing,YAO Heng,CHENG ZhengLong,DOU JunXia,ZHOU XiaoMing,FANG YuLin,SUN XiangYu
    Scientia Agricultura Sinica. 2019, 52(17):  3008-3019.  doi:10.3864/j.issn.0578-1752.2019.17.009
    Abstract ( 374 )   HTML ( 16 )   PDF (1144KB) ( 438 )   Save
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    【Objective】 The experiment was aimed at the high temperature stress in vineyard caused by extreme weather during summer, which leads excess rates of ripening, high sugar with low acidity of berries, and thus, affecting the quality of wine. This study explored the effects of spraying anti-transpirant treatment on photosynthetic characteristics, physiological indexes, quality of grape berries and wine, in order to provide a theoretical basis for improving quality of grape berries and wine in hot climate. 【Method】 Experiments were conducted in Heshuo (Xinjiang) in 2017, using Vitis vinifera L. cv. Cabernet Sauvignon (CS) and Vitis vinifera L. cv. Riesling as materials. The anti-transpirant was sprayed twice on July 26 and August 9, 2017. The grape leaves were sampled, while photosynthesis index, stomatal characteristics and physiological changes were measured; the relate index of ripening were monitored during pre-harvest period, while the glucose and fructose of berries were determined by Ultra Performance Liquid Chromatography (UPLC). Berries were harvested at the same time as winery (Riesling: August 16; CS: September 8), and CS dry red and Riesling dry white wine were made in small containers under standard verification process, then the basic physical and chemical indexes of the wine were determined after the fermentation was terminated. 【Result】 Anti-transpirant significantly reduced the net photosynthetic rate and stomatal conductance, but the intercellular CO2 concentration and transpiration rate were inconsistent in the two varieties. Scanning electron microscopy showed that the stomata width (41.02%, 46.94%), degree of opening (59.59%, 67.43%) and distribution density (13.84%, 4.97%) of CS and Riesling immature leaves were significantly reduced. In order to reduce the large amount of water loss in hot climate conditions; anti-transpirant treatment significantly reduced the content of malondialdehyde and free proline, and the soluble protein content of Riesling, and had no significant effect on chlorophyll content. The result showed that it provided a way to alleviate high temperature stress, and anti-transpirant could significantly inhibit the excessive accumulation of reducing sugar content and rapid degradation of organic acid. Compared to control group, anti-transpirant treatment reduced total sugar content in the CS and Riesling fruits by 6.6 g?L -1 and 11.7 g?L -1with total acid content increased by 0.57 g?L -1 and 0.76 g?L -1, respectively, , and the glucose and fructose contents were significantly reduced. The alcohol levels of CS and Riesling wines were reduced by 0.71% and 0.39%, compared to control group. 【Conclusion】 The anti-transpirant had the functions of regulating photosynthetic characteristics, reducing water evaporation, improving high temperature resistance, reducing sugar and alcohol content, and increasing acidity, which provided easy operation with low cost and multiple effects. The research results had certain practical guiding significance for improving the comprehensive quality of wine grape berries and wine in hot climate producing areas.

    Measurements and Modeling of the Impacts of Different Pruning Degrees on Transpiration of Apple Orchard in Hilly Regions
    YE MiaoTai,HUO GaoPeng,YANG Bo,ZHAO XiNing,GAO XiaoDong
    Scientia Agricultura Sinica. 2019, 52(17):  3020-3033.  doi:10.3864/j.issn.0578-1752.2019.17.010
    Abstract ( 338 )   HTML ( 21 )   PDF (815KB) ( 289 )   Save
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    【Objective】 Water deficiency is the major obstacle to restrict the development of apple industry of the Loess Plateau. This study was conducted to investigate the effects of pruning on apple transpiration, aiming to provide helpful information for water management and sustainable development of apple orchards. 【Method】 The study sites was located in Zizhou County, Shaanxi Province, where the apple trees were grown under rain-fed conditions. Sap flow under four pruning intensities, including CK (no pruning), PI-1 (light pruning), PI-2 (moderate pruning) and PI-3 (severe pruning), were measured with thermal dissipation probes. Combining with model simulations (MAESPA), the effects of pruning on transpiration of apple trees were studied.【Result】 The results showed that pruning could effectively reduce the leaf area index (LAI) of apple trees. The total branches, LAI and crown diameter of PI-3 decreased by 28.2%, 30.5% and 9.5%, respectively, compared with the CK. Pruning reduced the transpiration of apple trees significantly. At the intraday scale, when the pruning intensity increased, the peak value of sap flow decreased accordingly. Furthermore, the monthly transpiration gradually decreased from the fruit swelling period to fruit ripening period with the peak value in July and the lowest value in September. Transpiration of intensity II (PI-2) and intensity III (PI-3) was significantly lower than that of CK. During the study period, the transpiration of pruning intensity I (PI-1), intensity II (PI-2) and intensity III (PI-3) decreased by 11.1%, 24.1% and 37.9%, respectively, compared with CK (July-September). Meanwhile, the relationship between pruning intensity and transpiration was analyzed through MAESPA model. MAESPA model simulated the diurnal variation characteristics and daily transpiration of apple trees with a good accuracy. The normalized mean square error was between 0.163 and 0.293; the Nash coefficient was between 0.616 and 0.830 and the consistency coefficient was between 0.907 and 0.960. The results also showed that the model had a relatively poor performance when the photosynthetically active radiation (PAR) and saturated water vapor pressure deficit (VPD) were low. 【Conclusion】 Pruning effectively reduced the transpiration of apple trees. Under the context of light water stress in the Loess Plateau, PI-1 could be applied to orchard to reduce water consumption slightly; under the severe water deficit condition, PI-3 could be used as a promising measure to regulate water consumption of apple trees and promote the green healthy development of orchards.

    FOOD SCIENCE AND ENGINEERING
    Effects of Different Citric Acid Solutions on the Quality of Apricot Kernels During Debitterizing Mediated by Ultrasound Irradiation
    SHI FangFang, ZHANG QingAn
    Scientia Agricultura Sinica. 2019, 52(17):  3034-3048.  doi:10.3864/j.issn.0578-1752.2019.17.011
    Abstract ( 342 )   HTML ( 14 )   PDF (1496KB) ( 353 )   Save
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    【Objective】 In this paper, the effects of different pH values coupled with ultrasound irradiation on the color, texture and some physicochemical properties of the apricot kernels during debitterizing were investigated. Correlation analysis of all measured variables was conducted to simplify the evaluating indicators of the quality of debitterizing apricot kernels with different solvents. In addition, multivariate data analysis was applied to categorize the debitterizing solvents and provide the theoretical base for the selection of debitterizing solvents in the debitterizing processing of apricot kernels. 【Method】 Determinations of the amygdalin, water content and beta-glucosidase activity of the apricot kernels, and the contents of total phenols, proteins, reducing sugars and soluble solids in the debitterizing solutions were conducted by the high performance liquid chromatography, spectrophotometer and abbe refractometer, etc, respectively. In addition, the texture and organoleptic properties of the debitterized apricot kernels were also investigated by the texture analyzer and sensory evaluation test, respectively. Finally, principal component analysis (PCA) and cluster analysis (CA) were applied to classify the six kinds of debitterizing solvents. 【Result】 Compared with the untreated sample, the color, hardness, fracturability, chewiness, resilience, gumminess and sensory evaluation of the debitterized apricot kernels were significantly different after being debitterized by the six kinds of debitterizing solvents. In the meantime, the moisture content and the activity of beta-glucosidase of the apricot kernels increased significantly. Based on the comprehensive analysis of the physicochemical indicators, the debitterizing time was the shortest (only 90 min), and the loss of the nutrients in the apricot kernels was less than the other treated samples, when the pH of the debitterizing solution was at the value of 5. Correlation analysis showed a certain correlation among the indicators. The results of PCA and CA provided the same classification, and the six kinds of debitterizing solvents could be classified into three categories. Moreover, the effects of the different solutions on the apricot kernels in the same category were not significant. 【Conclusion】 The citric acid solution with a pH of 5 could be used as the optimal solution to remove the bitterness of apricot kernels, which not only accelerated the bitterness of apricot kernels, but also reduced the loss of nutrients of apricot kernels. All these results could provide the support for the industrial rapid debitterizing of apricot kernels.

    ANIMAL SCIENCE·VETERINARY SCIENCE·RESOURCE INSECT
    Protective Effect of Astaxanthin on Inflammatory Injury of Endometrial Cells in Bovine
    ZHANG Chen, TAN XiuWen, WEI Chen, ZHANG XiangLun, JIN Qing, LIU GuiFen, LIU XiaoMu, WAN FaChun
    Scientia Agricultura Sinica. 2019, 52(17):  3049-3058.  doi:10.3864/j.issn.0578-1752.2019.17.012
    Abstract ( 371 )   HTML ( 14 )   PDF (2071KB) ( 240 )   Save
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    【Objective】 The purpose of this study was to examine whether astaxanthin with strong antioxidant properties could protect endometrial cells against lipopolysaccharide (LPS)-induced inflammatory injury through mucosal barrier remodeling, so as to provide a theoretical basis for the prevention and treatment of bovine endometritis. 【Method】 The endometrial cells were cultured in the medium supplemented with 1 μg·mL -1 LPS for 6 h, then the inflammatory factors (such as TNF-α and IL-6) in the cultured medium were detected to establish an inflammation model in vitro. On this basis, the cultured medium was removed and fresh culture medium containing 1×10 -6 mol·L -1 astaxanthin was exchanged, and endometrial cells were further cultured for 24 hours. The control group was not added with LPS or AST, the LPS group was only added with LPS, and the LPS+AST group was added with LPS and AST. The inflammatory factors of TNF-α and IL-6 in the cultured medium and the activities of cellular SOD and CAT enzymes were detected by ELISA. The levels of reactive oxygen species (ROS) in the cells were detected by flow cytometry, and the distribution of tight junction protein, such as Claudin, CDH1 and TJP1, were observed by immunofluorescence staining. The mRNA and protein expression were examined by using fluorescence quantitative RT-PCR and Western Blot, respectively. 【Result】 The endometrial cells were cultured in the medium supplemented with 1 μg·mL -1 LPS for 6 h, the production of IL-6 and TNF-α in the cultured medium were significantly higher than those in the control group (P<0.05), indicating that LPS induced inflammation of endometrial cells. Compared with the control group, the level of intracellular ROS significantly increased (P<0.05), and the activities of cellular SOD and CAT enzymes significantly decreased (P<0.05), which indicated that LPS-induced inflammation in endometrial cells caused oxidative damage. When endometrial cells were further cultured in the medium containing 1×10 -6 mol·L -1 astaxanthin for 24 h, the levels of IL-6 and TNF-α in cultured medium were significantly lower than those in LPS group (P<0.05), the percentage of ROS positive cells decreased significantly (P<0.05), and the activities of SOD and CAT enzymes increased significantly (P<0.05). Compared with the control group, the fluorescence signals of Claudin, CDH1 and TJP1 proteins in the LPS group were weakened, and the levels of the mRNA and protein expression of tight junction proteins also decreased significantly (P<0.05). However, when compared with the LPS group, Claudin, CDH1 and TJP1 proteins with strong fluorescence signals were detected in cell margin and nucleus in LPS+AST group, and the levels of mRNA and protein expression also significantly increased (P<0.05).【Conclusion】 Astaxanthin reduced the oxidative damage which caused by inflammatory of endometrial cells, relived the structure damage of tight junction proteins in endometrial cells, which might protect the physical immune barrier of endometrium and provided theoretical reference for the prevention and treatment of bovine endometritis.

    The Expression Pattern and Ligand Binding Ability of Hc-FAR-4 Protein of Haemonchus contortus
    WEI HaiDian, CHEN XueQiu, HUANG Yan, SHI HengZhi, ZHOU JingRu, WU Fei, DU AiFang, YANG Yi
    Scientia Agricultura Sinica. 2019, 52(17):  3059-3068.  doi:10.3864/j.issn.0578-1752.2019.17.013
    Abstract ( 409 )   HTML ( 10 )   PDF (2206KB) ( 160 )   Save
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    【Objective】 Haemonchus contortus is a parasite mainly settled in the abomasum mucosa of small ruminants. The disease caused by H. contortus is a national epidemic in China. In this paper, the expression pattern and ligand binding ability of Hc-FAR-4 were studied to understand its role in the growth, development and reproduction of H. contortus.【Method】 The prokaryotic expression vector pET-30a-Hc-far-4 was constructed, which was identified by PCR and enzyme digestion identification, and then, the recombinant plasmid was transformed into E. coli BL21. The recombinant protein was induced by 0.1 mmol·L -1 IPTG (isopropyl-β-d-thiogalactoside). The recombinant protein rHc-FAR-4 was collected and was identified by Western Blot. Fluorescence analysis method, and then, which was used to study the binding ability of Hc-FAR-4 protein with DAUDA, retinol, and oleic acid. The IHF experiment was based on the fluorescent material retinol and fatty acid analogues DAUDA in polar or nonpolar solution, and their excitation spectra characteristics would change when they were excitated by a certain wavelength of exciting light. Using fluorescence analysis method, we could estimate whether rHc-FAR-4 protein contained the ability to bind with DAUDA and retinol by the change of the excitated spectra. When non-fluorescent oleic acid was added into the system, it would compete with DAUDA and retinol to bind with the bind site of rHc-FAR-4 protein, and which would make excitated spectral change, too. According to the changes, we could indirectly judge whether rHc-FAR-4 protein could bind with non-fluorescent oleic acid. At the same time, polyclonal antibodies were prepared by using rHc-FAR-4 protein to immunize mice, and the antibody titer of the immunized mice was tested by ELISA. The serum of the immunized mice would be collected if the antibody titer was appropriate. The collected serum was used in the immunofluorescence (IHF) experiment to explore the expression site of Hc-FAR-4 protein to speculate its function in H. contortus. The IHF experiment process was as follow: The H. contortus was embedded in paraffin; the paraffin was cut into slices; Antigen was repaired; the slices was incubated by 3% BSA at 4℃ for one night; slices was incubated by anti-Hc- FAR-4 mouse antibody and Alexa Fluor? 488 nm goat anti-mouse IgG antibody for 1 h, and which was done as primary and secondary antibody, respectively; after staining by DAPI, the slices were observed by confocal microscopy. What s more, the qPCR technology was used to analyze the expression characteristics of Hc-far-4 in H. contortus.【Result】 The target gene Hc-far-4 was successfully cloned. The recombinant plasmid pET-30a-Hc-far-4 was successfully expressed in E. coli BL21. The recombinant plasmid pET-30a-Hc-far-4 was successfully expressed in E. coli BL21, and the expression level of rHc-FAR-4 protein reached peak after induction for 8h. The result of ELISA showed that the titer of mouse polyclonal antibody was 1:1 024 000—1:2 048 000, which could be used in the following experiments. Western Blot result showed that the rHc-FAR-4 protein contained His tag and the band size was 25 kD, which was consistent with the prediction. The mouse polyclonal antibody was identified by Western Blot and could bind to natural Hc-FAR-4 protein, indicating that the antibody could be used in IHF experiment. The results of ligand binding experiments of rHc-FAR-4 showed that rHc-FAR-4 could bind to fatty acids and retinol. The qPCR analysis showed that Hc-far-4 reached the highest transcription level in the fourth stage larvae. Immunohistofluorescence assay showed that Hc-FAR-4 was mainly expressed in the intestinal wall and gland of H. contortus. To sum up, it could be speculated that Hc-FAR-4 protein might be involved in the transport of fatty acids and retinol, and provided nutrients for H. contortus to ensure its normal growth, development and reproduction; what ,s more, Hc-FAR-4 protein maybe also involved in the process of modifying host tissues to enable the parasite to escape the immunity of host.【Conclusion】 rHc-FAR-4 could bind to DAUDA and retinol, and which was mainly expressed in the intestinal wall, cuticle and gonad. The transcription level of Hc-far-4 reached the peak in the fourth stage larvae.

    Immune Responses of Apis mellifera ligustia to Nosema ceranae Stress
    FU ZhongMin,CHEN HuaZhi,LIU SiYa,ZHU ZhiWei,FAN XiaoXue,FAN YuanChan,WAN JieQi,ZHANG Lu,XIONG CuiLing,XU GuoJun,CHEN DaFu,GUO Rui
    Scientia Agricultura Sinica. 2019, 52(17):  3069-3082.  doi:10.3864/j.issn.0578-1752.2019.17.014
    Abstract ( 302 )   HTML ( 14 )   PDF (4827KB) ( 326 )   Save
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    【Objective】 The objective of this study is to reveal the cellular and humoral immune responses of Apis mellifera ligusitca worker’s midgut to Nosema ceranae stress, and to provide a basis for screening and functional study of key immune response genes by deep investigation of host differentially expressed genes (DEGs) and immune pathways.【Method】 Base on the previously obtained transcriptome datasets of normal and N. ceranae-stressed midguts of A. m. ligustica 7- and 10-day-old workers’ midgut samples (Am7CK, Am7T, Am10CK and Am10T), DEGs in each comparison group were filtered out following the standard FDR≤1, P≤0.05 and |log2 fold change|≥1. Additionally, Pearson correlations, Venn analysis, GO classification and KEGG pathway enrichment analysis were conducted by using related bioinformatic softwares. Further, DEGs enriched in immune pathways were summarized and analyzed. Finally, the reliability of transcriptome data was verified via real-time quantitative PCR (RT-qPCR).【Result】 Differential expression analysis showed that there were 472 up-regulated and 385 down-regulated genes in Am7CK vs Am7T comparison group, and 611 up-regulated and 360 down-regulated genes in Am10CK vs Am10T comparison group. Venn analysis suggested that the number of specific DEGs of the aforementioned two comparison groups was 739 and 853, respectively, and 118 DEGs were shared. GO classification indicated that the up- and down-regulated genes in Am7CK vs Am7T were respectively annotated to 23 and 29 functional terms; among them, the top five terms of up-regulated genes were binding, catalytic activity, metabolic process, cellular process and single tissue process; while the top five terms of down-regulated genes were metabolic process, single tissue process, catalytic activity, cellular process and binding. In addition, the up- and down-regulated genes in Am10CK vs Am10T were respectively involved in 36 and 26 functional terms; among them, the top five terms of up-regulated genes were single process, binding, cellular process, catalytic activity and metabolic activity; while the top five terms of down-regulated genes were binding, cellular process, catalytic activity, metabolic process and single process. KEGG metabolic pathway enrichment analysis showed that the up- and down-regulated genes in Am7CK vs Am7T were respectively enriched in 38 and 33 pathways, and among them the top five enriched pathways of up-regulated genes were bile secretion, endoplasmic reticulum protein processing, ubiquitin-mediated proteolysis, PI3K-Akt signaling pathway and neurotrophic factor signaling pathway; while the top five enriched pathways of down-regulated genes were cytoplasmic DNA-sensing pathway, purine metabolism, pyrimidine metabolism, RNA polymerase and ribosome; three cellular immune pathways including ubiquitin-mediated proteolysis, and seven humoral pathways including PI3K-Akt signaling pathway were detected. Additionally, the up- and down-regulated genes in Am10CK vs Am10T were respectively associated with 54 and 43 pathways, and among them the top five enriched pathways of up-regulated genes were Hippo signaling pathway, drug metabolism-cytochrome P450, metabolism of xenobiotics by cytochrome P450, ubiquitin-mediated proteolysis, and sphingolipid metabolism; while the top five enriched pathways of down-regulated genes were mRNA surveillance pathway, sphingolipid signaling pathway, fructose and mannose metabolism, galactose metabolism, and sphingolipid metabolism; seven cellular immune pathways including ubiquitin-mediated proteolysis, and two humoral pathways including NF-κB signaling pathway were found. The result of RT-qPCR verification demonstrated the expression trend of six randomly selected DEGs was consistent with that of the sequencing data, which confirmed the reliability of the transcriptome data. Further analysis noted that NF-κB signaling pathway was activated by N. ceranae in both 7- and 10-day-old workers’ midguts of A. m. ligustica, followed by immediate initiation of three antimicrobial peptides such as apidaecin, defensin-1 and hymenoptaecin, indicating their key importance in host defense against N. ceranae invasion.【Conclusion】 The immune responses of A. m. ligusitca worker’s midgut to N. ceranae were uncovered at transcriptomic level, and it was revealed that the host made both cellular and humoral immune responses at the early stage of N. ceranae stress. The host cellular immune responses may play a major role in resisting pathogen invasion. The host cellular immune continued to increase at the later stage of fungal stress, while the humoral immune drastically weakened. The ubiquitin mediated proteolysis and enriched DEGs, NF-κB signaling pathway and enriched DEGs, and antibacterial peptide-encoded genes such as apidaecin, defensin-1 and hymenoptaecin were likely to play pivotal roles in host immune response to N. ceranae stress.