近50年来天水市温度极值及相关天气现象对气候变化的响应

运用天水市7个国家气象站1961—2008年温度极值及相关天气现象资料,分析了其对气候变化的响应。结果表明,自1961年以来,该地年平均最高气温以0．36℃／10年的速度升高;年平均最低气温以0．40℃／10年的速度升高。增温幅度最大的时期出现在20世纪80年代以后。年最低气温≤0℃的日数以0．33d／年的速度递减;年平均最低地表温度以0．44℃／10年的速度增加;年极端最低地表温度以1．40℃／10年的速度增加;年结冰日数以0．33el／年的速度减少。温度极值及相关天气现象的变化必然会影响到种植业的布局及社会生活的许多方面。     

热带亚热带蔬菜种质资源的利用与蔬菜育种*

 植物种质资源是发展农业生产和开发育种工作的物质基础,现代蔬菜生产对育种工作提出了越来越高的要求,要求新品种在丰产性、抗病性、适应性和品质等方面都有较大程度地提高,而这些目标的实现,首先决定于所掌握的各种基因资源。热带亚热带地区由于雨量充沛,植被丰富,土壤类型繁多,而且小气候多样,地形错综复杂,海拔差异显著,加之农业历史悠久和多样化的耕作制度,因此,经过长期的自然选择和人工选育,形成了非常丰富的蔬菜种质资源。本文拟对我国热带亚热带蔬菜种质资源的利用现状进行回顾,主要概述了热带亚热带蔬菜种质资源的分布、蔬菜种质资源的多样性、蔬菜育种的研究现状和存在的问题及以后蔬菜育种的目标、途径等,以供育种工作者参考。     

杂交棉标杂A1和石杂2号超高产冠层特性及其与群体光合生产的关系

在田间自然条件下, 以标杂A₁、石杂2号为材料, 研究了超高产(3 500 kg hm^-2以上)杂交棉冠层的叶面积配置、叶倾角和光分布等冠层特性的变化及与群体光合生产的关系。结果表明, 超高产条件下杂交棉叶面积指数高且持续期长, 群体叶面积配置与光分布较均匀, 花铃期冠层中部有较好的透光性, 吐絮期底部漏光损失较小, 整个冠层仍保持较高的光吸收率。超高产杂交棉不仅群体光合速率峰值高, 而且高值持续时间长, 生育后期非叶器官仍维持较高的光合能力, 特别是茎的光合贡献率为常规高产棉花的1.6~4.9倍, 这是杂交棉在生育后期能保证群体光合优势的一个重要原因。超高产杂交棉的棉铃干物质空间分布与叶分布、光分布和冠层光合分布的比例吻合程度较高, 保证了光能的有效利用, 促进同化物及时向棉铃转运, 有利于挖掘杂交棉品种的增产潜力。     

中华绒螯蟹FAD6-b基因的全长克隆及原核表达分析

根据已登录的中华绒螯蟹一种Δ6去饱和酶基因(Accession Number:JX946434)及菁夜蛾去饱和酶基因(Accession Number:KJ622055.1)的保守区设计引物,通过逆转录PCR以及RACE技术克隆了中华绒螯蟹另一种Δ6去饱和酶基因FAD6-b的全长序列。经序列分析,中华绒螯蟹FAD6-b cDNA全长为2 310 bp,其中开放阅读框(ORF)为1 326 bp,共编码442个氨基酸(Accession Number:KP876058),理论分子量为50.86 ku,理论等电点为8.47,FAD6-b基因的氨基酸序列与已公布的一条中华绒螯蟹Δ6去饱和酶基因的一致性为76%。原核表达载体构建及其表达实验表明,中华绒螯蟹FAD6-b基因成功重组到原核表达载体pCold-TF DNA中,重组质粒pCold TF-fad6b在大肠杆菌BL21(DE3)pLysS中进行表达,经SDS-PAGE电泳分析表明,IPTG诱导后的重组菌出现了单一的蛋白条带,且大小与预期(105.86 ku)一致,可溶性分析显示目的蛋白主要存在于蛋白上清液中。对重组蛋白进行纯化,蛋白纯化液经电泳检测后显示出特异性单一条带,进一步证明了pCold TF-fad6b的成功构建和表达。目的蛋白经Western-blotting检测,结果表明获得的重组蛋白与6×His抗体进行了特异性结合,显示出良好的免疫学活性。     

The effects of high temperature level on square Bt protein concen-tration of Bt cotton

Higher boll worm survival rates were detected after high temperature presented during square period in Bt cotton. The objective of this study was to investigate the effects of high temperature level on the Bt efficacy of two different types of Bt cotton cultivars at squaring stage. During the 2011 to 2013 cotton growth seasons, high temperature treatments ranged from 34 to 44°C in climate chambers, and field experiments under high temperature weather with various temperature levels were conducted to investigate the effects of the high temperature level on square Bt protein concentration and nitrogen metabolism. The climate chamber experiments showed that the square insecticidal protein contents reduced after 24 h elevated temperature treatments for both cultivars, whereas significant declines of the square insecticidal protein contents were detected at temperature 38°C, and only slightly numerical reductions were observed when temperature below 38°C. Similar high temperature responses were also observed at the two field experimental sites in 2013. Correspondingly, high temperature below 38°C seems have little effect on the square amino acid concentrations, soluble protein contents, glutamic-pyruvic transaminase(GPT) and glutamic-oxalacetic transaminase(GOT) activities as well as protease and peptidase activities; however, when the temperature was above 38°C, reduced soluble protein contents, enhanced amino acid concentrations, decreased GPT and GOT activities, bolstered protease and peptidase activities in square were detected. In general, the higher the temperature is(38°C), the larger the changes for the above compound contents and key enzymes activities of the square protein cycle. The findings indicated that the unstable insect resistance of the square was related to high temperature level during square stage.     

浙江富阳金属冶炼厂周围水田土壤-水稻系统中As、Se含量特征

本文研究了浙江富阳金属冶炼厂周围水田土壤-水稻系统中As、Se含量特征。所采土壤样品中,As含量高于土壤环境质量一、二和三级标准的分别占总数的21.15%、9.62%和7.69%。该金属冶炼厂周围88.46%的土壤属于富Se土壤。足Se土壤占总样的5.77%,过量Se土壤占3.85%,高Se土壤占5.77%。水田土壤可能受与金属冶炼有关的点源污染影响。糙米的As、Se含量高于全国糙米As、Se背景值,可食部分As、Se浓度均未超过我国规定的水稻卫生标准。     

热带中东大西洋拟锥齿鲨生物学的初步研究

拟锥齿鲨是金枪鱼延绳钓渔业中常见的兼捕鱼种,处于海洋食物链的顶端,对海洋生态系统的稳定和多样性起着极其重要的作用。根据我国金枪鱼渔业国家观察员在热带大西洋海域（4.24°~14.03°N,38.28°~27.13°W）调查时采集的383尾拟锥齿鲨样本,按不同性别对其生物学特征进行初步研究。结果表明：拟锥齿鲨雌雄性比约为1∶〖KG-*2〗0.36,且存在显著性差异;雌、雄性拟锥齿鲨的优势叉长范围分别为75~95 cm、65~90 cm;雄性肝重指数与性腺的发育程度关系不明显,雌性性成熟个体的肝重指数小于未成熟个体;雄性成熟个体占雄性总数的96.8%,雌性性成熟度以Ⅱ期和Ⅳ期为主,性成熟个体占雌性总数的56.12%,雌性拟锥齿鲨50%性成熟叉长为84.6 cm;摄食等级以0级为主,其次为1级,分别占52.38%和〖KG*9〗33.86%;胃含物中以沙丁鱼出现频率最高,其次为鱿鱼,分别占72.56%和27.44%;雌、雄的叉长和重量关系式分别为：WR=2×10-5LF2.7614,WR=2×10-6LF3.3287。     

不同蜂授粉对设施草莓产量和品质的影响

通过比较熊蜂和蜜蜂对大棚栽培草莓的授粉效果试验得出,与蜜蜂相比,熊蜂的出巢时间早,工作时间长,趋光性差,撞棚膜现象发生少,且饲喂简单,饲料投入量少。采用熊蜂授粉的草莓平均产量可达16708.5kg/hm2,比采用蜜蜂授粉的棚增产35.0%;熊蜂授粉草莓单果质量为8.28g,比采用蜜蜂授粉的增加58.6%,差异显著;熊蜂授粉的草莓糖度为11.68%,蜜蜂授粉的草莓糖度为11.29%,差异不显著;熊蜂授粉的草莓畸形果率平均比蜜蜂授粉的低67.9%,差异显著。试验结果进一步说明了熊蜂比蜜蜂更适合用来进行设施草莓授粉。     

Effects of Supplemental Complex Water Soluble Vitamin on Production Performance,Blood Biochemical Parameters and Oxidation Resistance of Dairy Cows

The objective of the study was to investigate the effects of supplemental complex water soluble vitamins on production performance, blood biochemical parameters and oxidative resistance of dairy cows in spring and summer.The experiment was designed by 2×2 factorial randomized blocks design.Eighty healthy dairy cows with similar parity and body weight were randomly divided to four groups, with 7 days of adaptation and 70 d experimental phase.The dairy cows in group Ⅲ and Ⅳ were fed a basal diet supplemented with complex water soluble vitamins in spring.The dairy cows in group Ⅱ and Ⅳ were fed a basal diet supplemented with complex water soluble vitamins in summer.The results showed that the ADFI and daily milk yield of dairy cows receiving water soluble vitamin in spring were extremely significantly higher (P<0.01);The ADFI of dairy cows receiving water soluble vitamin was significantly higher in summer (P<0.05) and daily milk yield were extremely significantly higher (P<0.01);The butterfat rate was extremely significantly increased and SCC was extremely significantly decreased in spring and summer (P<0.01);Supplementation of water soluble vitamin was also significantly increased LYM (P<0.05).In summer, T-AOC, T-SOD were extremely significantly increased (P<0.01), and TP, CK, LDH, TP, HDL and ALB were extremely significantly decreased (P<0.01) by water soluble vitamin supplementation than that of control group.In conclusion, complex water soluble vitamins could increase the production performance and non-specific immune function, improve the oxidative resistance and relieved the heat stress of the dairy cows.     

“民工荒”背景下我国农村剩余劳动力转移动因与行为选择

我国农村有1.5亿～2亿剩余劳动力,并且每年以500万的速度递增,巨大的农村人口压力形成这样的论断:20世纪中国农村的最大问题是土地问题,21世纪中国农村的最大问题则是就业问题。农村剩余劳动力的城镇转移是我国农村发展最迫切的现实需要。但2003年以来,在我国城乡劳动力流动进程中,却出现了这样一个不可思议的现象——“民工荒”,并且愈演愈烈,这有悖于我国的基本国情。正是在这样的背景下,笔者对我国农村剩余劳动力的转移动因进行了深层次的理论探讨和剖析。