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1.
Possible Mechanism Associated with Herbicidal Activity of Soybean Meal Hydrolysate （SMH） 总被引：2，自引：0，他引：2
Soybean meal hydrolyzate （SMH） has been proposed for use as a natural preemergence herbicide.However,the mechanism by which SMH exerts its herbicidal activity remains unclear.In this paper,the herbicidal activities of SMH against perennial ryegrass （Lolium perenne L.） under non-sterile and sterile conditions were evaluated and the relationship between the molecular weight of the ultrafiltration （UF） fractions of SMH and their herbicidal activities were investigated.Besides,the ammonia content changes of the media of SMH treatments 7 d after incubation were also analyzed.The results showed that SMH inhibited the radicle growth of germinating L.perenne seeds in a dose-dependent manner under non-sterile condition.However,SMH in the concentrations investigated increased the radicle length and shoot length by 14-17% and 11-15% respectively under sterile condition.The ammonia contents in the SMH media at all treatments increased greatly from less than 0.01 mg L-1 to up to 11.86-41.37 mg L-1 after 7 d incubation under non-sterile condition.However,ammonia content did not change under sterile condition,proposing that the herbicidal activity might be caused by the free ammonia released from SMH by microbial activity.There was no difference on the perennial ryegrass radicle inhibition among the UF fractions of SMH on an equivalent N basis.It could be concluded that SMH exerted its herbicidal activity through the free ammonia released under non-sterile condition instead of by specific peptide（s） in SMH. 相似文献
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Effects of Four Pesticides on Grain Growth Parameters of Rice 总被引：1，自引：0，他引：1
WUJin-cai DONGBo LIDong-hu QIUHui-min YANGGuo-qing 《中国农业科学(英文版)》2004,3(5):364-370
Effect of four commonly used pesticides, triadlmefon, jingganmycin, triazoplos and imidacloprid, on grain growth parameters was examined using a growth equation in the present paper. Two hundreds of spikes, not damaged by pests were simultaneously marked per plot during the heading stage of rice. Rice plants were sprayed at 1 d after marking. Thereafter, 20 spikes were sampled at 4 d intervals and dried in an oven. Then, 10 superior and inferior grains were picked from each spike, and brown rice was weighed after shelling, respectively. First, second and third order derivates were deduced from K the following grain growth formula:W=K/l e^a-bt, where W was the weight of 100 grains brown rice at time t; K was maximum of grain growth; a and b were parameters of the formula. The parameters were calculated as following: R0=Kbe^a/(l e^a)^2 △t=t2-t1, GT=bk/4(t2-t1)=Vmax(t2-t1), Vmax=bk/4 Where R0, △t, GT and Vmax were initial growth power, active growth stage, accumulative weight of dried content during At and maximum growth rate, respectively. The result showed that GT and K of superior grain following 22.5 and 45 g a.i. ha^-1 of imidacloprid sprays were significantly reduced, and △t was significantly decreased for 112.5 and 225 g a.i. ha^-1 jingganmycin treatments. In addition, the high dose of imidacloprid significantly reduced the weight of 1 000 rice grains by 9.77%. However, there was no significant difference for the weight of i000 grains between the high dose of jingganmycin and the control, indicating that effective duration of jingganmycin on grain filling was shorter than that of imidacloprid. 相似文献
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LI Xiang-yang LIU Guo-shun YANG Yong-feng ZHAO Chun-hua YU Qi-wei SONG Shi-xu 《中国农业科学(英文版)》2007,6(6):665-672
The experiment was set up for examining the physiological and biological indexes quickly and exactly, for obtaining information of tobacco-field fertilizing and tobacco growing. The ASD Field spec FR 2500 was used to measure spectra reflectance of flue-cured tobacco and the relationship between hyperspectral parameters and biochemical contents （total nitrogen, chlorophyll, carotenoid）, and physiological indexes （fresh weight, dry weight, moisture content） of flue-cured tobacco leaves was studied by correlation and stepwise regression statistic methods at different nitrogen and potassium levels. The results indicated that the spectra curves of different treatments had obvious rules and great diversities. There were high correlations between different types of spectra parameters and ten physiological and biochemical indexes of flue-cured tobacco leaves. Hyperspectral characteristic variables of ten physiological and biochemical indexes were found through stepwise regression, and SDr/SDb was the characteristic variable closest to seven biochemical contents. Simultaneously, the R2 and regression coefficient of equations reached 0.05 significant level and the equations had good estimating effects through the examination of other samples. Accordingly, this study suggested that the ten physiological and biochemical indexes could be estimated quickly by the estimating models, at the same time nitrogen-potassium fertilization and growth condition of flue-cured tobacco could be inspected. 相似文献
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Optimization of Inactivation Conditions of High Hydrostatic Pressure Using Response Surface Methodology 总被引：2，自引：0，他引：2
GAOYu-long WANGYun-xiang JIANGHan-hu 《中国农业科学(英文版)》2004,3(7):528-534
Response surface methodology (RSM) was employed in the present work and a second order quadratic equation for high hydrostatic pressure (HHP) inactivation was built. The adequacy of the model equation for predicting the optimum response values was verified effectively by the validation data. Effects of temperature, pressure, and pressure holding time on HHP inactivation of Escherichia coli ATCC 8739 were explored. By analyzing the response surface plots and their corresponding contour plots as well as solving the quadratic equation, the optimum process parameters for inactivation E. coli of six log cycles were obtained as: temperature 32.2℃, pressure 346.4 MPa, and pressure holding time 12.6min. 相似文献
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Specific activity, substrate specificity, and kinetic parameters （Km and Vmax） of glutathione S-transferases （GSTs） towards three substrates, 1-chloro-2,4-dinitrobenzene （CDNB）, 1,2-dichloro-4-nitrobenzene （DCNB）, and p-nitrobenzene chloride （pNBC） were investigated in six tissues （foregut, midgut, hindgut, fat body, hemolymph, and muscle） of Oxya chinensis. In addition, the inhibition in vitro （ethacrynic acid, and Cibacron Blue 3GA） of Oxya chinensis in the six tissues was also investigated. Glutathione S-transferase activity was detected in all the six tissues examined. The rank order of GST activities towards CDNB was fat body 〉 midgut 〉 hindgut 〉 muscle 〉 foregut 〉 hemolymph both in females and males. Glutathione S-transferase activities in the fat body in females and males were 1.3- to 10.4-fold and 1.1- to 10.0- fold higher than those in the other tissues. The rank order of GST activities towards the other substrates changed slightly. From these results, it was inferred that GSTs in the fat body and midgut played important roles in detoxifying xenobiotics including insecticides and plant allelochemicals in O. chinensis. In the three substrates examined, CDNB seemed to be the best substrate, followed by pNBC and DCNB. The kinetic parameters of GSTs were different among the six tissues. This suggested that GSTs in different tissues have various affinities and catalytic efficiency to substrates. In vitro inhibition study showed that the median inhibition concentration （IC50） values of the two inhibitors to GSTs from the six tissues were different. The results suggested that the two inhibitors have different inhibition potency to GSTs from the different tissues. The observed changes in kinetic parameters and inhibition in vitro among the six tissues of the insect might suggest that the number and structure of isoenzymes and their rate of expression varied for the different tissues. 相似文献
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ZHAO Xiaofeng XU Fenghua HE Huixia WAN Shuming 《东北农业大学学报(英文版)》2007,14(1):31-35
The research was aimed at studying the effect of adding certain proportion chicken manure to cattle manure on compost below 0℃ with aerobic compost method, which was suitable for northern cold climate. The results indicated that the mixed compost completed 3 days earlier than the single compost, the temperature of the mixed compost rose to 50.7℃ at the 1st day,and achieved its highest temperature 74.4℃ at the 3rd day. The temperature of the single compost rose to 40.0℃ at the 1st day,rose to 55.6℃ at the 3rd day,and achieved its highest temperature 70.1℃ at the 5th day. Adding chicken manure had no impact on the variety trend of the process parameters such as moisture content,pH and C/N ratio, but increased the variety range of these parameters. 相似文献
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A large portion of irrigation farmers make use of subjective （intuition） irrigation scheduling methods as supposed to objective or scientific irrigation scheduling methods, which need to be changed. The BEsproeiingsWAterbestuursprogram （BEWAB＋） irrigation scheduling programme is based on the water balance equation and needs： （1） a crop production function; （2） a relative consumptive water demand curve and （3） an allowable depletion subroutine. The objective of this paper was to describe research aimed at obtaining information on （1） and （2） for pea and also to describe the effect of water application on yield and water use of pea. BEWAB＋ uses this information to estimate the daily irrigation water requirements for a particular soil-crop-atmosphere system under irrigation. A field experiment, based on published line-source irrigation methodology, was conducted on a 3 m deep loamy fine sand Bainsvlei or Ustic Quartzipsamment soil near Bloemfontein （26°08′S; 29°01′E） in South Africa. Results showed that there is a linear relationship of the form Ys = 8.07ET - 249 （r2 = 0.91）, where Ys is the seed yield of pea （kg/ha） and ET is evapotranspiration for the growing season （mm）. The relative consumptive water demand curve is represented by the following third order polynomial function that describes the relationship between time and relative ET for a pea growing season of 120 days： ETrelx = 0.09419646 - 0.01302413x ＋ 0.00059008x2 - 0.00000371x3. ETrelz denotes relative ET and x denotes time in days. A workable balance between practical problem solving and advanced irrigation science has been established with BEWAB＋. Pre-plant irrigation schedules can be made for semi-arid areas with the BEWAB＋ programme using easily obtainable inputs, like target yield, soil depth and soil particle size distribution information. 相似文献
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JinYi 《东北农业大学学报(英文版)》1995,2(1):66-74
The analysis method of the triple test cross design has been discussed carefully form the two factor experiment design and the genetic models of additive-dominant effect and of epistasis effect-Two points different from the previous reprots have been concluded:(1)both the degrees of freedom of the orthogonal terms C2 and C3 are m;(2) the denominator in the F test to C2 and C3 is the error mean of square between plots. 相似文献
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DingKe－wei TakeoKayaba 《东北农业大学学报(英文版)》2001,8(2):105-110
Genetic parameters for milk,fat yield and age at first calving of Chinese Holsteins in Heilongjiang were evaluated using multiple-trait restricted maximum likelihood procedures with an animal model.Data consisted of records of 2496 Chinese Holsteins first lactation cows collected from 1989 to 2000.The model included 21 herd effects,four calving season effects,nine age at first calving effects,6697 animal effects.(Co) variance components of milk yield,fat yield and age at first calving were estimated with software package for variance component estimation(VCE) by an animal model.The heritabilities were 0.14,0.21,0.38 for milk yield.fat yield and age at first calving ,respectively,.The estimates of genetic correlation between milk yield and fat yield ,age at first calving were 0.96,-0.29,respectively,The estimate of genetic correlation between fat yield and age at first calving was -0.28. 相似文献
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导数光谱在棉花农学参数测定中的作用探讨 总被引：5，自引：0，他引：5
通过大田和室内试验,测定了2个品种的棉花冠层、完全展开倒3叶在不同时期的高光谱反射率及对应叶片的叶绿素、类胡萝卜素含量,分析并证实了棉花导数光谱时消除测量背景影响及寻找特征波长方面的作用。将导数光谱用于棉花农学参数的测定,发现棉花冠层和叶片光谱都存在红边位移现象,并且红边参数(红边位置、红边幅值、红边面积)与叶面积指数、鲜叶重、干叶重和叶绿素含量有显著相关,从而证明用棉花导数光谱测定它的某些农学参数的可行性。 相似文献
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气力输送应用广泛，但存在着能耗高等缺陷。应用虚拟仪器技术可实现气力输送能耗参数的自动检测。检测系统的硬件包括气力输送装置、孔板、压差传感器、扭矩传感器、变频调速器、可控硅、数据采集板等。系统软件应用Lab Windows／CVI实现数据的分析、计算和处理，得出检测试验的回归方程。基于虚拟仪器的气力输送能耗参数检测系统可显示能耗指标与其参数的关系曲线，并得出能耗最小时的最佳参数组合。 相似文献
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胡守忠 《内蒙古农牧学院学报》1998,19(1):121-123
当视点位置不同时，物体的透视投影会产生失真的感觉，为了消除这一现象，本文试图从到时候从理论上进行讨论并对失真参数进行确定。 相似文献
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开展航天载荷软件可靠性参数的研究是进行航天载荷软件可靠性工程的基础.首先定义并解释了航天载荷应用软件可靠性,并依据软件可靠性参数选取的原则提出了一个航天载荷应用软件可靠性参数集,解释并分析了航天载荷系统中常用的软件可靠性参数.该参数集是进行航天载荷软件可靠性设计与分析的前提. 相似文献
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卵巢早衰(premature ovarian failure,POF)发病率逐年上升,病因繁杂,缺乏有效的治疗手段。POF早期准确预测和干预是改善妇女生活质量和生育缺憾的有效途径之一。目前,越来越多的研究表明,难以通过单一指标对卵巢早衰进行有效预测。那么,筛选出便捷、无创的预测指标,通过数学模型构建一个高效的卵巢早衰预警系统显得尤为重要。危险因素、INH-B、AMH、AFC、CCCT、自身抗体、BMP-15基因突变、卵巢间质血流等可作为POF预测性参数;FSH/LH、FSH等可作为POF验证性参数。 相似文献