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991.
本文研究了诱导热带假丝酵母子囊孢子产生和子囊破壁的条件,以及单倍体分离和鉴别方法。结果表明:NaAc、KCl这两种成分即可满足热带假丝酵母的产孢营养要求,在含有NaAc8.2gm、KCl1.8gm的琼脂培养基中,28℃培养7d,热带假丝酵母细胞的产孢率可达到47.5%;单纯使用蜗牛酶对破除热带假丝酵母子囊壁的效率甚低,酶解液加入适量的石英砂同时振荡处理4h左右,可以显著提高对热带假丝酵母子囊破壁速率。用这种方法处理,绝大多数子囊壁均可破除。子囊破壁处理后再以52℃处理10min杀死残余的营养体细胞,分离物的单倍体孢子比例可由灭活处理前的48%,提高到76%以上。  相似文献   
992.
研究不同品质粗饲料混合日粮及添加酵母培养物对瘤胃内几种主要纤维素酶酶活及纤维物质降解的影响。试验将带有永久瘤胃瘘管的9只绵羊随机分成3组,以粗饲料分级指数GI为指标对粗饲料品质进行划分,在精粗比为2:8条件下配制3种混合日粮,形成含高GI粗饲料日粮组(H组,粗料GI值=2.89)、含中GI粗饲料日粮组(M组,粗料GI值=1.73)和含低GI粗饲料日粮组(L组,粗料GI值=0.65)。利用DNS法研究瘤胃内几种主要纤维素酶酶活的变化以及对纤维物质降解的影响。试验结果表明:3个试验组木聚糖酶的活性在饲后2h内下降,以后逐渐升高,到8h时达到最高并保持平稳;滤纸酶活和果胶酶活与粗饲料品质之间没有明显的规律性;添加酵母培养物(YC)后能够增加木聚糖酶活和果胶酶活,而M组和L组滤纸酶活有减少的趋势,但差异均不显著(P>0.05)。由本研究可知:3个试验组随着粗饲料品质的升高,木聚糖酶活有增加的趋势;果胶酶活和滤纸酶活未表现出一定的规律性。添加酵母培养物后有提高木聚糖酶活和果胶酶活的趋势,3个试验组的DM、NDF、ADF有效降解率都有不同程度的增加。  相似文献   
993.
Kuhn Tucker optimality conditions and Lagrange multipliers for vector optimization problems with subconvexlike set valued maps wereestablished by Li zemin. Firstly, the concept of generalized subconvexlikeness for set valued maps is introduced in this paper. Then, a theorem of the alternative for generalized subconvexlike set valued maps in real linear spaces is established. Finally, the optimality conditions for vector optimization problems with set valued maps with equality and inequality constraints are obtained with it.  相似文献   
994.
The focus of this study was to evaluate a feed enzyme (Rovabio Excel) in diets fed to commercial broilers reared in environments typical to that observed in the US broiler industry and destined to be marketed at BW at or near 2.5 kg. The feed enzyme was tested in diets differing in amino acid and energy composition. The main effect of altered nutrient levels, mainly reduced amino acids, was higher abdominal fat at processing. The formulation addition of the exogenous feed enzyme to diets differing in nutrient contents and energy did not affect broiler live performance or carcass traits. However, the exogenous feed enzyme decreased 14-d mortality in experiment 1 and 41-d mortality in experiment 2 but was without effect on mortality in experiment 3. Future research elucidating any benefits on mortality from the exogenous feed enzyme may aid commercial poultry producers. Further, reducing dietary nutrient levels beyond that considered in this study may allow for exogenous enzyme benefits in broiler live production and carcass traits to be observed as mediated through nutrient liberation.  相似文献   
995.
大杯伞生物学特性研究   总被引:6,自引:1,他引:5  
大杯伞(Clitocybe maxima)是八十年代驯化成功的食用菌新品种.本文详细描述了其子实体发育的四个时期—一棒形期、钉头期、杯形期、成熟期的形态特征.以及菌褶子实层、单核菌丝、双核菌丝中的丝状菌丝、粉状菌丝和产孢菌丝团的显微构造;阐述了大杯伞生活史中的三个有性大循环和一个无性小循环,说明其有性世代可不必经过伞形子实体阶段,而由产孢菌丝团和粉状双核菌丝直接产生担子和担孢子来完成;对大杯伞生长发育各个阶段的温度、营养、水分、光照、空气和pH值等要求也作了较详细论述.  相似文献   
996.
On the basis of a long-term field experiment with a progessive monoculture of wheat carried out on the research station Hohenschulen (University of Kiel), the yield reaction of wheat in monoculture was analysed with help of a multiple regression approach.
The mean yield of several years declines till the third resp. fourth crop, it increases later ('decline-effect' in the larger sense) without reaching the initial level however.
The weather considerably influence the absolute yield level as well as the yield trend in dependence upon the number of successive wheat crops. Interactions between yield and soil conditions are only slightly marked if the absolute yield is considered. The yield components, however, react differently according to the soil conditions.
Crop management measures such as the choice of varieties and the application of BCM-fungicides or N-fertilization were only able to reduce yield losses, but not to prevent them.  相似文献   
997.
本文研究了Cu-D370催化漆酚氧化聚合成膜的反应条件和产物性能。Cu-D370的含铜量超过5%时才有正常的催化活性。与漆酚相反,Cu-D370催化活性随升温而加快,89℃时不失活,而且其底物漆酚出现沉淀的时间比70℃或45℃时出现短。粗产品数均分子量(Mn)为3420,分子量分布窄。分离出残余漆酚和低聚物之后,其漆膜实干时间不到1天。漆膜物理性能优异,与“超级生漆膜”类似。漆膜的耐热性和耐化学品性与普通生漆差不多。  相似文献   
998.
Summary Potato stock plants of five commercially propagated varieties, which derived from tissue culture, were grown at a low light irradiance in non-aseptic conditions. The plants produced tiny-leaved etiolated stems, which were a good source of cuttings for further propagation. The method was tested by growing micropropagated and cutting propagated plants as three lines of stock plants, based on different clonal generations, and which were repeatedly harvested for cuttings. There was wide variation in the multiplication capacity among the varieties used. The most productive variety produced more cloned potato plants than when micropropagated in vitro. Stock plants derived from single-leaf cuttings produced more new cuttings than when derived from tissue culture. The growing facilities used were simple and inexpensive and could be set up anywhere. The method is economically competitive due to the need of only very simple and inexpensive growing rooms, and would be worth using particularly in developing countries and also in advanced potato production. All the cuttings of different harvests rooted well and the last propagated cuttings of the lines were still free of prevalent viruses although using simple growing facilities.  相似文献   
999.
松阳县生态公益林建设现状与发展对策   总被引:2,自引:0,他引:2  
通过对松阳县生态公益林建设现状及存在问题的分析,为今后的发展提出了相应的对策.  相似文献   
1000.
草酸在化学工业中应用广泛,其生产方法有多种。介绍用淀粉为原料,以硝酸为氧化剂的氧化法生产草酸的实验方法。利用正交试验法找出较好的生产工艺条件,达到提高草酸产率的目的。  相似文献   
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