栉孔扇贝异精雌核发育四倍体早期胚胎发育的细胞学荧光显微观察

用1500μW/cm2的紫外线照射长牡蛎(Crassostrea gigas)精子60 s以进行灭活处理,并使之与栉孔扇贝(Chlamys farreri)卵子受精,在卵子受精后排出第一极体前用6-DMAP(50 mg/L)处理受精卵,持续处理35 min,抑制第一极体和第二极体的排放,诱导异精雌核发育四倍体。采用二脒基苯基吲哚(DAPI)荧光染色显微观察法,对灭活的长牡蛎精子诱导的栉孔扇贝雌核发育四倍体早期胚胎发育过程进行细胞学观察。结果表明:经紫外线灭活过的长牡蛎精子进入栉孔扇贝卵子后发生轻微膨胀;在第一次卵裂中期,精核形成一致密的染色质小体(DCB),位于两组分开的母本染色体之间,不参与核分裂;第一次卵裂结束时DCB滞留于两卵裂球的分裂沟上或进入其中一分裂球中;第二次卵裂过程中,DCB的去向与第一次卵裂时基本一致。6-DMAP处理有效地抑制了第一极体和第二极体的排出,从而使雌核四倍化。对担轮幼虫染色体倍性分析结果表明,通过本方法可以获得6.25%的四倍体幼虫。本研究还对灭活的异源长牡蛎精子诱导栉孔扇贝雌核发育四倍体过程中产生的复杂倍性、核物质分离紊乱及多精附卵现象进行了观察和分析。     

不同水肥调控措施对冬小麦产量影响的研究

水分不足和养分缺乏是制约广大旱作农业地区生产发展的两个关键因素.以冬小麦为供试作物,采用田间试验的研究方法,探讨了不同水肥调控技术措施(施肥和补充灌溉)对冬小麦产量和水分利用效率等之间的关系,获得了主要结论:中水中肥冬小麦产量最高,其水分的利用效率也最高.     

南京牛首农副产品合作社专题调研的思考

农民专业合作经济组织是由从事同类农产品生产经营的农民自愿组织起来．在农业生产经营的产前、产中、产后等环节实行资金、技术、信息、生产、供销等互助合作与服务的经济组织，是市场经济条件下，农民进行自我服务、自我发展、自我保护的一种行之有效的组织形式。在对南京牛首农副产品合作社进行专题调研的基础上，拟从南京牛首农副产品合作社的实践分析入手，提出进一步发展壮大江宁区农民专业合作经济组织对策和建议。     

源于马铃薯Y病毒CP基因的dsRNA原核表达及提取

以马铃薯Y病毒(Potato virus Y,PVY)为基础构建了含PVY CP基因3’端253bp反向重复片段的双链RNA(dsRNA)原核表达载体,并转化大肠杆菌HT115(DE3),经IPTG诱导产生dsRNA,用LiCl沉淀法提取,获得了高质量的dsRNA。     

Differentiation of human bone marrow-derived stem cells into insulin-producing cells in vitro and in vivo

AIM: To explore the possibility of differentiating functional insulin-producing cells from human BM-derived stem cells. METHODS: Mesenchymal stem cells were isolated from human bone marrow. Then these cells were induced with epidermal growth factor, β-mercaptoethanol and high concentration of glucose. The gene expression related to islet β cells was detected by RT-PCR. Insulin in the treated cells was examined by immunocytochemistry. In addition, the levels of insulin secretion and glucose-stimulated insulin release were examined by microparticle enzyme immunoassay. Finally, the induced cells were implanted into the right renal subcapsular space of diabetic mice. Blood glucose levels were monitored 16 d after implantation. The right kidneys of the treated mice were harvested for immunohistochemistry. RESULTS: The key genes related to pancreatic β cells had been confirmed to express by PCR and insulin was detected by immunocytochemistry in differentiated human BM-derived stem cells induced by high glucose, which responded to glucose challenge. Furthermore, implantation of the cells in renal subcapsular space was able to lower the glucose levels in hyperglycemic mice. After 16 days, the implanted cells were determined still to be insulin positive cells by immunohistochemistry. CONCLUSION: These results indicate human BM-derived stem cells are capable of differentiating into functional insulin-producing cells and may represent a pool of cells for the treatment of diabetes.     

昆虫化学信息物质概述

昆虫化学信息物质以其微量i高效、无污染、与农药兼容等特点而成为当前世界各国昆虫学家研究的热点问题，它们的应用范围非常广泛，本文对昆虫化学信息物质的概念进行了综述，阐述了其包含的种类的相互关系和相应的概念以及在农、林业害虫领域中的应用效果，展望了昆虫化学信息物质的发展前景。     

油松育苗不同时间播种效果的试验

油松育苗播种时间不同,效果明显不同,适时早播,不仅能提高苗木对病虫害的抵抗力,躲过苗木出土初期的日灼,还由于延长了苗木生长期,可增强木质化程度和抗寒、抗旱性能,为安全越冬创造有利条件,并能提高单位面积优质苗产量。所以,油松育苗实行适时早播十分重要。     

枣中糖测定的研究进展

综述了枣中糖的分离、提纯和测定的研究进展，并对目前研究存在的问题及以后的发展前景进行了讨论。     

“NSI—415”保水剂在干旱区林业建设中的应用

基于多途径提高水资源利用效率的目的,通过对保水剂的功能、应用技术的论述,分析保水剂在干旱区林业建设中的应用方法及对不同树种的影响效应,结果表明:保水剂对干旱区常见造林树种作用显著,可提高高生长13%-18.1%。对于梭梭、柽柳、沙枣等灌木树种,施用保水剂可将困难立地条件下造林成活率提高14%。