晚期罗氏沼虾苗短周期养殖试验

本文报导了7月底育成的0.7～0.9厘米罗氏沼虾苗,每平方米放养25尾左右,与鱼混养,经104天的饲养,达到了每公顷产罗氏沼虾1528公斤和鱼种2661公斤。平均每公顷经济效益达31315.5元,投入产出比为1:1.82。罗氏沼虾的成活率为67.9％。平均规格为9.1克/尾,雄虾最大个体重达24克,雌虾达15.8克。85％的虾体长在7～9.7厘米。文章还讨论了进一步提高规格和产量的可能性。     

夏季南京雨花台景区不同绿地类型与大气污染的关系

在南京雨花台景区内,选取不同结构的绿地类型进行群落调查,包括无林地、草坪、疏林草地、道路绿地及密林地。针对南京大气污染的特点,在夏季的晴天和雨天两种不同天气情况下,对不同绿地进行离地面1.5 m高大气SO2、NO2及可吸入颗粒物(PM10)质量浓度的测定,分析绿地与大气污染的关系。结果表明:雨花台景区大气中的SO2和NO2质量浓度均符合国家《环境空气质量标准》(GB 3095—1996)中的一级标准,PM10的质量浓度符合国家的二级标准;晴天,不同绿地类型下,大气污染物SO2、NO2及PM10的质量浓度差异显著,无林地>乔灌结构的道路绿地>乔灌草结构的密林地,乔灌草复层结构类型的绿地环境效应最佳;雨天,由于降水对大气污染物的净化作用,绿地对大气污染物的影响不明显。     

Insecticides in Chinese medicinal plants: survey leading to jacaranone,a neurotoxicant and glutathione-reactive quinol

Sixty-two plant species from central China were purported to have insecticidal activity. Adult house fly (Musca domestica) toxicity assays were used to identify the two most active plants and guide the chromatographic isolation of the insecticidal components. The active ingredient of Senecio palmatusPall. (Asteraceae) was characterized as methyl (1-hydroxy-4-oxocyclohexa-2,5-dien-1-yl)acetate (jacaranone) (1), previously known to have insect antifeedant activity. Mono- and bisglutathione (GSH) adducts are formed on incubation of 1 with GSH and rat liver GSH S-transferase. The toxic action of 1 in mice (intraperitoneal LD(50) = 150-200 mg/kg) is associated with both neurological signs and GSH depletion in liver 90 min after treatment. Paeonia suffruticosa var. papaveracea (Andr.) Kerner (Paeoniaceae) was the other active plant found here to have 2'-hydroxy-4'-methoxyacetophenone (paeonol) (2) as an insecticidal ingredient in the root and in one case, for the whole plant, contaminated with S-tert-butylthiomethyl O,O-diethyl phosphorodithioate (terbufos) (3), a synthetic anticholinesterase insecticide.     

长江江豚的饲养和观察

本文报道了对饲养下的长江江豚的行为、食物数量的观察和疾病治疗实验结果。在饲养状态下,江豚除正常的游泳姿势外,也表现侧游、跳跃、直立、滚游和滑行等姿态。呼吸间隔大多在10～20秒之间,最短为3秒,最长为43秒。每日3～8时的呼吸间隔均值略大于其它时间。一般游泳速度为1.3米/秒。日投喂量可达其体重的10％左右。对鱼类没有选择性。对疾病治疗可参考家畜的用药种类和剂量。     

绵羊肌肉生长激素受体基因表达的发育性变化研究(英文)

[Objective] The study aimed to explore the expression of muscular growth hormone receptor gene (GHR) in sheep at the early stage of growth and development. [Method] The GHR mRNA expression levels in longissimus dorsal muscles of male Kazak sheep and Xinjiang fine wool sheep with different ages were quantitatively analyzed by real time PCR. [Result] Sheep GHR mRNA expression level in longissimus dorsal muscle increased firstly followed by decline, and then kept steady until the end of the experiment, with the expression peak appearing on postnatal day 30. The GHR mRNA expression level of Kazak sheep was extremely lower than that of Xingjiang fine wool sheep from 2 to 90 days old (P<0.01). [Conclusion] Both age and breed had great effects on the expression of muscular GHR gene in sheep.     

Study on Nitrogen Forms in Chaohu Lake and Wabu Lake Sediments

Composition and distribution of nitrogen in Chaohu Lake and Wabu Lake sediments were studied.The results showed that the mean total nitrogen content in Chaohu Lake and Wabu Lake was 0.533 g/kg and 0.265 g/kg respectively,and the primary composition of nitrogen was organic nitrogen(94%).The organic index indicated that the organic pollution degree of Wabu Lake was lower than that of Chaohu Lake.     

分子标记ST10对水稻条纹叶枯病抗性基因Stv-b~i的检测

近年来,利用与抗病基因紧密连锁的分子标记进行辅助选择已经成为抗病育种的重要手段。本研究利用显性标记ST10对24个水稻品种以及24个水稻品种中的镇稻88/武育粳3号和武运粳7号/徐稻3号的2个F2群体进行检测。PCR结果显示,17个抗病品种有8个能扩增出约727bp的目标片段;在镇稻88/武育粳3号杂交组合中,感病亲本武育粳3号和F2群体中的8个感病单株均不能扩增出目标片段,抗病亲本镇稻88、F1和13个不感病单株中的11株都能够扩增出目标片段;用于检测的武运粳7号/徐稻3号的F2群体中,8株感病单株没有检测出目标片段,而13株不感病的单株有9株扩增出目标片段。结果表明,ST10与条纹叶枯病抗性基因Stv-b^i紧密连锁,表现为共分离。     

水稻93-11 EMS诱导突变体的分离与鉴定

利用EMS对籼稻品种93-11进行诱变处理,以构建基因突变群体。M1单本移栽并单株收获。M2播种5000个家系,根据各个生育阶段表现鉴别出411个家系发生了形态突变,并收获271个家系。M3代对M2代收获材料按照系谱法进行跟踪观察和验证。结果表明,形态性状的突变频率为8．22％。其中一些突变体具有优良农艺性状,有可能在育种中得到利用。     

杆式滴头的研究与试验应用

杆式滴头是微灌技术中滴水器系列的一个新品种,属于非压力补偿式紊流滴头,具有结构简单,水力性能好,堵塞后可方便地拆下清洗,成本低,使用寿命长等优点。对其结构设计,水力性能,制造水平以及试验应用均作了详细论述,为广大用户和微灌工程设计人员提供了该滴头的结构特征及性能数据,以便正确选用。     

欧洲水仙鳞片扦插繁殖技术

以单朵大花欧洲水仙品种的大鳞茎为材料,按不同基质、切分方式、消毒药剂来进行扦插繁殖。结果表明,每鳞茎切分数量以八分法所得的鳞茎切块,较16分法的鳞茎切块生根更多,鳞茎切块的小鳞茎增殖率也较高,但总的小鳞茎增殖数量按每大球算以十六分法的更多,多4个;3种扦插基质中,珍珠岩作为鳞茎块增殖的基质较理想;感病方面的控制以甲基托布津和多菌灵混合的较好。