钴离子(Co~(2 ))对月季鲜切花生理结构的影响

在实验室常温条件下，将月季（ＲｏｓａＣｈｉｎｅｓｅｓｊａｃｑ．）鲜切花品种“萨蒙莎”置于２％蔗糖和不同浓度ＣｏＣｌ２溶液进行瓶插培养．在有蔗糖提供营养的基础上，Ｃｏ２＋可以延缓细胞膜差别透性的降低，抑制月季茎切口端和培养液微生物特别是真菌的生长，并能维持茎中央薄壁细胞和花瓣表面乳突状细胞的完整性，减少“弯颈”现象的发生．     

网状内皮组织增殖病病毒感染SPF雏鸡外周血液T,B淋巴细胞数量变化

应用ＳＰＡ菌体花环法检测网状内皮组织增殖病病毒（ＲＥＶ）感染ＳＰＦ雏鸡外周血液Ｔ、Ｂ淋巴细胞数量动态变化。结果发现，１日龄ＳＰＦ雏鸡感染ＲＥＶ后７～４９ｄ外周血液Ｔ淋巴细胞数量，１４～４９ｄＢ淋巴细胞数量均明显低于对照组。表明感染ＲＥＶ的ＳＰＦ雏鸡外周血液的细胞免疫和体液免疫水平均下降。     

金融系统ARCH模型及应用

针对金融数据具有丛集性与异方差性的特征，给出了最能反映这一特征的研究方法，在此基础上，比较系统地介绍了ＡＲＣＨ模型及其若干变形，参数估计与假设检验，讨论了金融系统ＡＲＣＨ模型的应用前景。     

内蒙古阿拉善左旗4年采用机械模拟飞播牧草效益调查

阿拉善左旗４年机械模拟飞播牧草累计面积为２９８０ｈｍ＾２，实播面积为２９８０ｈｍ＾２，１９９７年１０月调查，保存面积为２９７０ｈｍ＾２，保存面积率为９９．７％，４年来播区植被盖度提高８．９６倍，有苗面积率提高３１．５３倍，牧草产量提高３５．９１倍，第一性生产产值和第二性生产产值分别是飞播总投资的０．６７倍和０．９７倍，机械模拟飞播牧草表现出明显的经济效益、生产效益和社会效益。     

对乙酰氨基酚对大鼠原代肝细胞的损伤机制

胶原酶两步灌流法获取SD大鼠的原代肝细胞,并用不同剂量的对乙酰氨基酚处理.MTT法测定肝细胞的存活率,分光光度法测定培养上清液中乳酸脱氢酶(LDH)的含量.Western blotting法测定大鼠肝细胞中细胞色素P450酶2E1(CYP2E1)的表达水平.结果表明,对乙酰氨基酚可导致肝细胞存活率降低,LDH含量显著升高,CYP2E1表达增加.说明达到一定的剂量时.对乙酰氨基酚可引起肝细胞的损伤.     

加拿大农业行政管理与税收政策对我国的借鉴

加拿大农产品在国际市场上具有较强的竞争力,国家对农业的保护是一个重要的因素,但这种保护主要不是靠补贴或关税,而主要是通过发展农业的有关法律和法规来体现。加拿大已经建立起了较完备的农业管理体制,而且对农业的干预或扶持政策都有明确的机构负责实施。与加拿大相比,虽然在农业管理体制上我国与加拿大有所不同,但是随着我国城乡统筹协调发展和农业现代化进程的加快,以及农业的集约化、产业化水平的进一步提高,加拿大农业行政管理体制和税收政策对我国具有很强的借鉴意义。     

Performance of Agricultural Systems under Contrasting Growing Season Conditions in South-western Quebec

Climate change will alter temperature and rainfall patterns over North American agricultural regions and there will be a need to adapt crop production systems to the altered conditions. A set of field experiments were conducted in south-western Quebec, Canada, with soybean ( Glycine max L.), corn ( Zea mays L.), sorghum ( Sorghum bicolor L.) × sudangrass ( Sorghum sudanense Piper) hybrid and switchgrass ( Panicum virgatum L.) under two tillage and three nitrogen fertility regimes, to study their performance in three successive growing seasons (2001–2003), two of them with unusually warm and dry conditions. The annual crops were established in two tillage systems: conventional and no-till (NT). All crops except soybean were fertilized with three levels of nitrogen: corn – 0, 90 and 180 kg N ha⁻¹, sorghum-sudangrass – 0, 75 and 150 kg N ha⁻¹, switchgrass – 0, 30 and 60 kg N ha⁻¹. The 2001 and 2002 seasons were hotter and drier than the 2003 season, which was the most favourable for crop growth. The capacity of the crops to yield in dry seasons was as follow: switchgrass > sorghum-sudangrass > corn > soybean. The corn and sorghum-sudangrass responses to nitrogen fertilizer were low in 2001 due to the combined effect of dry growing season and coarse soil texture. Soybean did not perform well under NT. Corn yielded better at the highest nitrogen fertilizer rate under NT when the early season was warmer than the normal. Our results show that switchgrass and sorghum-sudangrass could be an option in south-western Quebec if the frequency of hot and dry seasons increase in the future, because of climate change.     

葡萄根癌土壤杆菌的不同生化型对葡萄及其它植物致病性的初步研究

 从北京、内蒙古、吉林、辽宁、山东等地采到的葡萄根癌病标本中,分离到根癌土壤杆菌[Agrobacterium fumefaciens(Smith&Town.) Conn]3种生化型菌株。它们对玫瑰香葡萄的致病性明显不同。生化Ⅲ型菌株致病性强,形成大、中型瘤。生化Ⅰ型、Ⅱ型菌株致病性弱,只形成小瘤。生化Ⅲ型的不同菌株对葡萄、向日葵、烟草、番茄等8种植物的致病性也很不同。一类只能侵染葡萄,是窄寄主型;另一类除葡萄外,还能侵染向日葵、烟草、番茄,是宽寄主型。玫瑰香、龙眼等葡萄对3种生化型菌株比较敏感;莎巴珍珠、贝达等比较抗病。生化Ⅲ型和Ⅰ型的一些菌株也能侵染梨、李、杏、樱桃、榆叶梅等几种果树。从山东白雅葡萄上分离的BS33-10菌株(胭脂碱质粒类型)接种在烟草、番茄上能形成畸嵌瘤。     

苏丹草种子生产及市场浅析

对当前苏丹草种子生产，市场出现的问题，提出了解决途径和方法，以法制化制约市场，保护生产者，经营者和消费者的合法权益。     

陕西省关中地区玉米青枯病病原菌及其致病性的研究

 玉米青枯病(茎腐病)是世界性玉米产区重要病害之一。近年来,国内有发展和加重的趋势,并成为抗病育种的重要障碍。