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31.
食用型向日葵杂交种主要性状的典型性相关分析   总被引:5,自引:3,他引:5  
试验针对食用向日葵育种中存在的实际问题,对其主要性状进行典型性相关分析研究。结果表明:食用向日葵产量性状与形态性状、生育期之间的相关主要是由产量性状中的单盘粒数、籽实产量和形态性状中的株高、叶片数及生育期的相关引起。以上结果可为食用向日葵杂交育种研究提供依据。  相似文献   
32.
Fate of urea nitrogen(N) applied to rape grown on a red soil was investigated by the 15N mass balance technique.and efficiency of urea and effect of nutrients balance in raising rape yield were investigated in a field plot experiment.One hundred and thirty -eight kg N/ha,86kg N/ha as basal dressing and 52 kg N/ha as top dressing,was applied with band application technique.The experiment was conducted in the southeast of china ,near Yingtan City,Jianxi Province.Results from 15N mass balance study showed that when urea urea was applied as basal dressing the plant recovery was 44.0% of the applied N for Treatment T (with application of N,P,K,B and lime),Plant recoveries were 38.0%-40.5% for Treatments-K,-B-lime and RS(without application of K,B or lime as well as with additional rice straw compared with Teatment T),which were not significantly different from Treatment T.In contrast ,plant recovery was only 5.1% for Treatment-P(without application of P), indicating that P was the factor limiting N uptake by rape.However,N remaining in 0-0.30 m soil was high up to 71.6% for Treatment-P,while the corresponding data were 33.0%-42.6% for the other treatments.The total recovery of applied N(including plant recovery and N remaining in 0-0.60 m soil) was 91.5% for Treatment T when urea was applied as basal dressing,while almost all the applied N was recovered when ureawas applied as top drssing,It was suggested that N loss was greatly controlled by using band application method in this experiment.Results from the field plot experiment field plot experiment showed that N supply capacity of this red soil was very low,and the efficiency of the applied N was quite high,7.1kg rape seed was increased by application of one kg N for Treatment T.Nitrogen and phosphorus were the key factors limiting rape yield,and the yield was very low when neither of them was applied.The yield in Treatment-K was significantly lower than that in Treatment T,With the former accounting for 77% of the later.  相似文献   
33.
近年来,巴彦淖尔市设施农业发展迅速。但随着该市设施农业发展规模的不断扩大,在建设、生产、销售等方面逐渐凸显出一些问题。阐述了当前巴彦淖尔市设施农业的发展状况,并针对存在的主要问题提出了相应对策。  相似文献   
34.
哈尔滨地区犬旋毛虫对猪,犬的感染性研究   总被引:3,自引:1,他引:2  
用消化法所得的犬旋毛虫蚴分别接种猪,犬。结果表明:犬旋毛虫对猪、犬的感染性存在着明显差异,在犬的繁殖力指数为18.68。而在猪为零,说明哈尔滨地区犬旋毛虫相当于本地毛形线虫。犬旋毛虫对犬易感而对猪不感染,通信能通过猪的感染而对人体健康构成威胁。  相似文献   
35.
两种蔗糖浓度对切割取样鼠胚冷冻解冻效果的研究   总被引:1,自引:0,他引:1  
小鼠晚期桑椹胚、早期囊胚和扩大囊胚,经切割取样分别采用0.365M和0.25M蔗糖浓度进一步细管和分步脱除甘油解冻后体外培养发育率分别为65.5%、46.4%和75.4%,两种浓度间差异显著(P<0.05);分步脱除甘油解冻瑟前者差异不显著(P>0.05),与后者差异极显著(P<0.01)。  相似文献   
36.
HJJ-80型卧式饲料搅拌机的设计   总被引:1,自引:0,他引:1  
随着畜牧业的发展,对饲料数量及质量有了更进一步的需求。搅拌机是饲料加工中的关键设备,因此搅拌机的正确设计对生产饲料的质量及经济性有着重要影响。为此,按照饲料配方的要求,根据提出的主要技术参数,确定了整机的结构尺寸及配套动力,设计和试制了饲料搅拌机。  相似文献   
37.
采用单因子试验设计法,测定肉仔鸡感染柔嫩艾美耳球虫(E.tenella)后对粪便中水分变化的影响。试验表明:感染柔嫩艾美耳球虫后,鸡的生产性能受到显著的影响(P<0.05)。粪便中水分含量高于未感染组,感染后4d粪便中水分含量呈上升趋势,研究认为,粪便中水分含量的增加是球虫感染后的鸡的病理性变化的一种生理反映。在临床上,可将鸡粪便中水分含量的变化作为评判鸡感染球虫的参考指标之一。  相似文献   
38.
The chlorinated fumigants chloropicrin (trichloronitromethane) and 1,3-dichloropropene (1,3-D) are extensively used in agricultural production for the control of soilborne pests. The reaction of these two fumigants with hydrogen sulfide species (H2S and HS-) was examined in well-defined anoxic aqueous solutions. Chloropicrin underwent an extremely rapid redox reaction in the hydrogen sulfide solution. Transformation products indicated reductive dechlorination of chloropicrin by hydrogen sulfide species to produce dichloro- and chloronitromethane. The transformation of chloropicrin in hydrogen sulfide solution significantly increased with increasing pH, indicating that H2S is less reactive toward chloropicrin than HS- is. For both 1,3-D isomers, kinetics and transformation products analysis revealed that the reaction between 1,3-D and hydrogen sulfide species is an S(N)2 nucleophilic substitution process, in which the chlorine at C3 of 1,3-D is substituted by the sulfur nucleophile to form corresponding mercaptans. The 50% disappearance time (DT50) of 1,3-D decreased with increasing hydrogen sulfide species concentration at a constant pH. Transformation of 1,3-D was more rapid at high pH, suggesting that the reactivity of hydrogen sulfide species in the experimental system stems primarily from HS-. Because of the relatively low smell threshold values and potential environmental persistence of organic sulfur products yielded by the reaction of 1,3-D and HS-, the effects of reduced sulfide species should be considered in the development of alternative fumigation practices, especially in the integrated application of sulfur-containing fertilizers.  相似文献   
39.
冬枣绿盲蝽的发生与无公害防治   总被引:3,自引:0,他引:3  
近年来绿盲蝽已成为我国冬枣的主要害虫。其刺吸冬枣幼嫩部分的汁液进行危害,造成花芽分化不良,落蕾落花,叶片穿孔,枣果畸形脱落,导致严重的经济损失。本文综述了绿盲蝽的分布、发生规律和危害特点,分析了其成灾原因。针对目前绿盲蝽发生的特点以及防治中的问题,介绍了冬枣园绿盲蝽无公害化防治技术。  相似文献   
40.
通过高盐选择性培养基平板分离法,从陕西定边盐湖土壤样品中分离筛选极端嗜盐菌株,并通过传统的表型特征(包括形态学观察、生长因子实验、生理生化特征)和系统发育学16S rDNA序列分析鉴定嗜盐菌株的分类学地位。结果表明,分离筛选出1株最适生长盐浓度在10%-15%的细菌菌株A355,初步鉴定其为中度嗜盐菌,属于厚壁菌门(Firmicutes)芽孢杆菌科(Bacillaceae)枝芽孢菌属(Virgibacillus salarius sp.)。  相似文献   
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