【Objective】 Downy mildew, caused by Plasmopara vitic ola, is the most serious disease in grape. Severe yield losses are caused wherever the weather during the growing season is humid and rainy. The objective of this study is to understand the effect of rain-shelter cultivation on airborne sporangia of P. viticola , define the relationship between airborne sporangia and changes of disease index, reveal the control of rain-shelter on the pathogen source, determine the control of rain-shelter on the pathogen source, analyze the primary infection sourced under the cultivation and provide a basis for formulating comprehensive control of the disease. 【Method】Form July to September during 2013, the diseased leaf and disease index on the same shoots were investigated under rain-shelter and open-field cultivation, respectively. The data were used to fit the regression models of dynamic of grape downy mildew under the two cultivations by regression curve estimation in SPSS19.0, the epidemic phases and rate of the disease were derived based on the data. The sporangia of P. viticola were investigated under rain-shelter and open-field cultivation. The dynamics of airborne sporangia were compared under two different cultivations, the relationship between airborne sporangia and changes of disease index in the key epidemic phase were analyzed. The main source of sporangia in the key epidemic phase and the main influence factors of airborne sporangia were cleared by comparing the effect of rain-shelter on the horizontal and vertical sporangia dispersal. 【Result】The seasonal epidemic curves of grape downy mildew under rain-shelter and open air cultivation were typical single peak S curve. The logistic model could reflect the temporal dynamic of grape downy mildew well by using SPSS19.0. The epidemic phases under the two cultivations, the exponential phases were from July 5th to July 23rd and August 18th to August 30th. The logistic phases were from July 23rd to August 19th and from August 30th to September 17th. The degenerating phases were from August 19th to the end of grape growing season and September 17th to the end of grape growing season. The seasonal airborne sporangia under open-field cultivation were a multi-peak curve. The daily rainfall had significant effects on the concentration of airborne sporangia. The peak periods were July to August and August to September under the two cultivations. Rain-shelter cultivation significantly reduced the number of airborne sporangia, thereby reduced the contact probability of sporangia and grape leaves in shelter facilities, and achieved the goal of reducing basic number of germs. Sporangia were trapped earliest on border row of the shelter facilities. The first trapped time delayed, and the concentration of airborne sporangia diminished with the closer to the center. Grape leaf canopy had significant barrier on airborne sporangia in horizontal direction. The concentration of airborne sporangia diminished with the increase of height under the two cultivations. There was a significant barrier effect of rain-shelter facilities on the airborne sporangia close to the roof. 【Conclusion】The first visibility of the disease and the first trapped time of airborne sporangia were significantly delayed, the epidemic process of the disease and cycle of airborne sporangia were significantly shortened, epidemic degree of the disease and airborne concentration of sporangia were significantly reduced by rain-shelter facilities. There were significantly barrier effects on both rain-shelter facilities and grape canopy. The sporangia matured on the spot under open-field cultivation, discharged in rain and dispersed with airflow, finally provided main inocula for the epidemic of the disease under rain-shelter cultivation.

【目的】葡萄霜霉病是葡萄生产上最重要的病害之一,在多雨潮湿地区常造成严重的产量损失。研究旨在明确避雨栽培对葡萄霜霉病菌( Plasmopara viticola )孢子囊飞散的影响,确定孢子囊飞散与病情变化之间关系,揭示避雨栽培对病菌数量的控制作用,推测避雨栽培下霜霉病的初侵染来源,为葡萄霜霉病的科学防控提供理论依据。【方法】2013年生长季7—9月份,分别对沈阳地区露地和避雨栽培小区内葡萄霜霉病发病情况进行定株定枝系统调查,统计得到病叶率和病情指数。应用SPSS19.0中回归曲线估计程序构建葡萄霜霉病流行时间动态模型,获得能描述不同栽培模式下葡萄霜霉病发病动态的模型参数,并推导2种栽培模式下霜霉病流行时期和流行速率。通过对田间小区内的孢子囊飞散进行定期监测,对比不同栽培模式下孢子囊飞散时间动态差异,探索关键流行时期内病害流行速率与捕孢量之间的关系。对比分析避雨栽培对葡萄霜霉病孢子囊水平、垂直方向飞散的影响,明确关键流行时期内孢子囊的主要来源和孢子囊飞散的主要影响因素。【结果】避雨和露地栽培下葡萄霜霉病的季节流行曲线趋势一致,均表现为典型的S形曲线。应用SPSS19.0软件分析,明确了Logistic模型能够反映沈阳地区葡萄霜霉病流行时间动态情况。露地和避雨栽培下病害流行时期：指数增长期分别为7月5—23日和8月18—30日,逻辑斯蒂增长期分别为7月23日至8月19日和8月30日至9月17日,衰退期分别为8月19日至葡萄生育末期和9月17日至葡萄生育末期。露地栽培下整个生长季孢子囊飞散表现为多峰曲线,当日降雨对孢子囊飞散有显著的冲刷作用。沈阳地区露地和避雨栽培下孢子囊飞散盛期分别为7—8月和8—9月。避雨栽培可明显降低空中孢子囊数量,从而减少孢子囊与避雨设施内葡萄叶片的接触概率,达到降低菌源基数的作用。避雨设施边行最早捕获孢子囊,且数量最多,随着逐渐向中心靠近,首次捕孢时间逐渐推迟,数量逐渐降低。葡萄叶幕对于孢子囊水平方向的飞散具有显著的阻隔效应。不同栽培模式下均以接近地面处的捕孢量最大,且随着高度增加,捕孢量逐渐减少。避雨设施对于接近棚顶处的孢子囊飞散有着显著的遮蔽作用。【结论】避雨栽培可推迟葡萄霜霉病始发时间和首次捕孢时间,缩短病害流行过程和孢子囊飞散周期,显著降低病害流行程度和孢子囊飞散数量。孢子囊飞散受到葡萄叶幕和避雨设施显著的阻隔效应。避雨栽培下葡萄霜霉病的初侵染主要为本地露地栽培下葡萄霜霉病病株上的病斑产生的孢子囊。

Although rain-shelter cultivation is getting more attentions in horticulture crops production，its effect on formation of volatile compounds remains unclear. In present study，fruits of cultivar‘Yulu’（Prunus persica L. Batsch‘Yulu’）were grown under rain-shelter and open field as the control，and the fruit were harvested at different maturity stages. Real-time data indicated that rain-shelter treatment significantly reduced soil relative humidity and light transmission，but no significant changes were found for air temperature，relative humidity and soil temperature eleven classes of volatiles wereidentified in peach fruit by solid phase microextraction coupled to gas chromatography mass spectrometry techniques，including C6 compounds，aldehydes，alcohols，esters，lactones，terpenes，terpenoids，phenylpropanoids and others. Peach fruit treated with rain-shelter cultivation could be clearly distinguished from the controls by partial least squares discriminant analysis（PLS–DA），being consist with results produced by electronic nose analysis. Eighteen volatile compounds that contributing to differences in volatile compositions between rain-shelter cultivation and open field fruit were identified based on variable importance in projection（VIP）value. Peach fruit treated with rain-shelter produced higher contents of “green note”C6 alcohols such as（Z）-3-hexenol and（E）-2-hexenol，and lower concentrations of“fruity note”γ-Undecanolactone，γ-Decalactone and（Z）-3-Hexenyl acetate.

避雨栽培在园艺植物生产中得到了越来越多的应用，而有关该技术对果实挥发性物质形成的影响并不清楚。研究以中国水蜜桃品种‘玉露’为试材开展避雨栽培，以露地栽培作为对照，不同成熟阶段分别取样直至商业采收。实时数据监测显示覆膜的避雨栽培并不显著改变果园空气温度、相对湿度和土壤温度等微环境，但显著降低了土壤相对湿度并减弱了光照。采用顶空固相微萃取（HS–SPME）结合气相色谱质谱联用（GC–MS）方法在桃果实中鉴别出包括碳六化合物、醛类、醇类、酯类、内酯类、萜烯类、萜烯类衍生物和苯环化合物等11大类挥发性物质。利用偏最小二乘判别分析（PLS–DA）构建的模型可以明显区分避雨栽培和露地栽培的桃果实的挥发性物质，与电子鼻技术检测的结果相似。根据变量投影重要性指标（VIP）鉴别出了不同栽培模式下浓度具有显著差异的18种挥发性物质，整体趋势表现为避雨栽培果实产生了较高浓度的顺–3–己烯醇、反–2–己烯醇等“青香型”物质，而顺–3–乙酸己烯酯、γ–十一内酯和δ–癸内酯等“果香型”物质含量较低。

Bicinchoninic acid (BCA) method was used for determining protein content in milk and compared with Kjeldahl method. Meanwhile, the resistance of BCA method to interference of urea, a nitrogen-containing interferer, was analyzed. Results showed that an average absorbance at 562 nm wavelength was obtained in precision test of BCA method, and the standard deviation was 0.004. Spike recoveries at two levels of protein determined by BCA method were within the range of 98.00%－ 103.00%. In 6 replicated experiments, average values of protein content in 50- and 100-fold diluted milk were determined to be 791.2 and 803.4 μg/mL by BCA method and 370.2 and 384.0 μg/mL by Kjeldahl method, respectively. Experiments on urea interference revealed RSDs below and over 5% for protein determinations by BCA and Kjeldahl methods, respectively. As a conclusion, BCA method has the advantages of simplicity and good reliability, stability and resistance to urea interference, thereby providing an attractive alternative to Kjeldahl method for protein determination.

目的：建立二喹啉甲酸(BCA)测定牛奶中蛋白含量的方法。方法：用BCA 法和凯氏定氮法分别测定食用牛奶蛋白含量；同时，添加尿素作为含氮干扰因素，测定其对BCA 蛋白定量方法的影响。结果：BCA 法蛋白定量精密度实验显示，平均吸光度为0.2798，标准偏差为0.004，加标回收实验的回收率为98.00%～103.00%。分别测定50 倍、100 倍牛奶稀释样品，结果50 倍稀释样品组BCA 法和凯氏定氮法测得蛋白质量浓度的平均值分别为791.2μg/mL 和803.4μg/mL，100 倍稀释样品组分别为370.2μg/mL 和384.0μg/mL。添加尿素干扰实验显示，BCA法实验结果相对标准偏差在5% 以下，而凯氏定氮法大于5%。结论：BCA 法测定牛奶中蛋白含量结果可靠、稳定，与凯氏定氮法相比无显著差异；BCA 法能排除含氮物质的干扰，该方法操作简便、结果准确可靠，可替代微量凯氏定氮法。

In order to discover the variation regularity of main sugar and organic acid during fruit development of peach, fruits of each developmental stage of 21 varieties were used to measure sucrose, glucose, fructose, sorbitol, malate, citrate and quinate wing HPLC. Similar regularities of sucrose were found in dfrferent varieties, as steady or small growth in early stage, continued with a sharp growth 30 to 50 d before fruit mature. Small decrease was happened in some varieties 10 d before harvest. Similar regularities ofcitrate were also found in dfrferent varieties, as high content in early stage, and a sharp decrease 10 to 30 d after flower, continued with contant low content, then a small growth, content of citrate decrease before harvest in most varieties. No distinct variation regularities were found in fructose, glucose, sorbitol, malate and quinate. During fruit developing, significant conelation between sucrose and fruit size, fructose and glucose were found in all 21 and 20 varieties, respectively. Flavors of matured fruit were significant positive conelated with sir crose, pH and sugar/ acid at 0.O1 level, and signfricantly positive conelated with total sugar at 0.O5 level. Flavors of matured fruit were signfricantly negative conelated with titratable acid, malate and total acid at 0.O1 level.

为了研究桃果实发育过程中可溶性糖及有机酸的变化规律, 以21份各类型桃种质为试材, 采用高效液相色谱测定果实发育过程中主要糖和有机酸含量。发现蔗糖含量在所有试材中均呈前期平稳或小幅增长, 成熟前30~50d快速积累的趋势, 部分品种采前小幅降低; 各品种柠檬酸含量也呈类似的变化, 前期最高, 花后10~30 d均有显著的大幅下降, 此后出现小幅的升高后平稳, 采前大部分品种降低。果糖、葡萄糖、山梨醇、苹果酸、奎尼酸品种间差异大, 且无明显的变化趋势。通过相关性分析发现, 果实发育过程中, 各试材蔗糖与果实大小均呈显著的正相关, 有20个品种的果糖和葡萄糖含量呈显著的相关性; 果实成熟时风味与蔗糖、pH、糖酸比之间存在极显著的正相关, 与总糖含量呈显著的正相关, 与可滴定酸、苹果酸、总酸存在极显著的负相关。