东北地区节水农作制度研究

针对我国东北区粮食生产的地位与水资源供应的现状,研究该区主要作物的耗水特性,给出节水种植结构调整建议,认为灌溉农业应"压稻扩玉豆",雨养农业应"稳玉豆,扩谷油,增林经".比较了该区节水种植模式的产量与节水效益,认为应以一年一熟制粮食作物单作为主.分析了该区主要节水技术的节水效果与经济效益,认为应优先发展耕作保墒类与覆盖保墒类等节水技术.     

胡萝卜联合收获机高效减阻松土铲设计与试验

针对胡萝卜联合收获机作业时松土铲普遍存在作业阻力大、漏拔率高等问题,设计了一种高效减阻松土铲。以狗獾爪趾为仿生原型设计了仿生减阻铲尖,并分析了其减阻机理,建立了铲翼与土壤间的力学接触模型,确定了影响松土铲作业质量的铲翼结构参数。基于EDEM离散元仿真技术,建立了部件土壤作物多元仿真模型,通过单因素试验与正交旋转组合试验,确定了铲翼结构参数取值范围及其对指标的影响规律。建立了试验因素与指标间的多目标优化数学模型,运用Design-Expert 8.0.6软件确定了松土铲的最优参数组合,通过田间性能试验验证了高效减阻松土铲的作业性能。结果表明:影响胡萝卜联合收获机松土铲作业质量的主要结构参数为铲翼开角α和铲翼倾角β,当铲翼开角α和铲翼倾角β分别为120.27°和47.37°时,松土铲作业性能最优,最优组合下前进阻力与胡萝卜拔取力分别为1908.76 N和55.37 N。经田间性能试验验证,田间试验结果与仿真优化结果基本一致,与凿式松土铲相比,高效减阻松土铲前进阻力降低了5.79%,胡萝卜拔取力降低了20.68%,漏拔率降低了3.8个百分点,满足胡萝卜收获农艺要求。     

绵羊痘病毒甘肃流行株膜蛋白ORF23基因的克隆及序列分析

从甘肃景泰县疑似患羊痘的绵羊皮肤组织中提取基因组DNA,PCR扩增膜蛋白ORF23基因.序列分析表明,该基因由1113个核苷酸组成,编码370个氨基酸,A+T含量占69.90%,G+C含量仅占30.10%.绵羊痘病毒甘肃株ORF23基因与A株、NISKHI株之间的核苷酸同源性分别为99.6%和99.5%,氨基酸同源性分别为98.7%和98.4%;与皮肤疙瘩病病毒NW-LW株和山羊痘病毒Pellor株之间的核苷酸同源性均为98.2%.结构预测显示,ORF23膜蛋白为非分泌蛋白,具有一个O连结糖基化位点.可见,ORF23膜蛋白在不同的绵羊痘病毒流行株之间非常保守,具有潜在的疫苗和诊断研究价值.     

海带岩藻聚糖硫酸酯电渗析分离工艺

采用电渗析法对盐沉后的海带酶解液中岩藻聚糖硫酸酯进行分离,探索工业化分离生产岩藻聚糖硫酸酯的方法,以解决目前乙醇沉淀法存在的安全性和高成本等问题。以脱盐率、糖保留率为检测指标,采用响应面法优化了电渗析工艺参数。结果显示,在操作电压80 V、料液流量3.2 L/min、固形物浓度10 mg/ml、p H=5的条件下,电渗析连续循环3次,海带酶液解干基中多糖含量由40.17%提高至47.11%,硫酸根含量由3.36%提高至4.97%。电渗析后海带酶解液干基中的金属离子含量为Ca 0.13 mg/g、Mg 16.04μg/g、Cu 0.29μg/g、Se 11.7μg/g、Cr 8.06μg/g,Pb未检出,较电渗析前均有降低。电渗析对脱除褐藻胶的海带酶解液进行脱盐纯化处理,可有效地分离纯化出岩藻聚糖硫酸酯。     

地面覆盖对花椒园热量平衡的影响

对花椒林地进行覆膜、覆秸秆和种植三叶草3种方式覆盖,测定不同覆盖条件下冠层的辐射能环境、热量平衡及水分环境.结果表明,地面覆膜、覆秸秆和种植三叶草条件下,地面反射率提高,增加了冠层净辐射,树冠下层接受的反射辐射分别较对照提高69.1%、48.0%和35.7%;树冠中部净辐射能分别较对照提高53.3%、26.3%和0.8%.在热量平衡中,覆膜、覆秸秆和种植三叶草的花椒林潜热通量分别占净辐射能的60.2%、62.4%和65.8%,感热通量分别占净辐射能的36.5%、34.0%和30.6%,土壤热通量分别占3.3%、3.6%和4.2%.     

两种物理方法破碎大肠杆菌比较试验

采用超声波和反复冻融两种物理方法,对一定浓度的标准致病性大肠杆菌进行破碎率比较试验。结果表明:在试验条件下,超声波破碎法达到97%以上的破碎率所需时间为30~50min,尤其是菌液浓度为每毫升50亿,用Ф10变幅杆破碎,30min破碎率可达99.9%。而反复冻融破碎,无论液氮的低温冷冻人为速溶或自溶,还是采取冷冻箱的冻融,达到50%以上的破碎,要耗时数小时,且要经过预冷冻的过程。     

Lethal and Sub-Lethal Effects of Transgenic Rice Containing cry1Ac and CpTI Genes on the Pink Stem Borer,Sesamia inferens（Walker）

Lethal and sub-lethal effects of transgenic rice containing crylAc and CpTI genes on the pink stem borer, Sesamia inferens,were studied to collect information for ecological risk assessment on insect-resistance of transgenic rice. In vitro insectfeeding bioassays were conducted to evaluate the lethal and sub-lethal effects oftransgenic flee lines (Ⅱ YouKF6 and KF6)containing crylAc+CpTI genes on S. inferens at four different growth stages, viz., seedling, tillering and elongation, booting,and milk and maturing. Transgenie rice at seedling stage showed significantly high lethal effect on S. inferens with the shortest lethal duration for 50 and 100% individuals and the highest corrected mortalities after feeding on transgenic lines at this stage for 3 and 6 d. Followed by tillering and elongation stage, 50 and 100% S. inferens were dead after feeding on transgenic lines at this stage for 4 and 10 d, respectively. Moreover, corrected mortalities for 6 d feeding on transgenic lines at this stage were significantly higher than that at booting, and milk and maturing stages. Lethal effect of KF6 on S. inferens decreased significantly at booting stage. Lethal duration for 50% S. inferens significantly extended and its corrected mortalities for 6 d feeding also declined remarkably. However, lethal effect of Ⅱ YouKF6 on S. inferens did not decrease significantly at this stage. Transgenic rice at booting, and milk and maturing stages did not show significant lethal effect to S. inferens and it showed the longest lethal duration for 50% individuals and the lowest corrected mortalities for 3 and 6 d feeding. A few larvae of S. inferens could survive, pupate and emerge on these two transgenic lines at booting, and milk and maturing stages. Sub-lethal effect of two transgenie lines on S. inferens also differed significantly between different developmental stages. Continuously feeding on transgenic rice lines at seedling, and tillering and elongation stages delayed the development of larvae and pupae and decreased pupation rate, but no effect was observed on eclosion rate. Larval development was significantly inhibited after feeding on transgenic rice at booting stage, but no obvious effect was observed in pupal stage, pupation and eclosion rate. There were no significant differences for larval and pupal development, pupation,and eclosion rates between feeding on transgenic and control rice lines at milk and maturing stage. Larval and pupal weights significantly declined, but no influence was observed on fecundity when S. inferens infested on transgenic rice at any stage.These showed that there were significant differences in lethal and sub-lethal effects of transgenic rice on S. inferens among developmental stages, and the effects gradually decreased with the increase of growth stages of rice plant.     

青海小麦孢囊线虫病的发生分布及田间识别

对小麦孢囊线虫病在青海省的发生分布概况、田间发病症状进行了介绍,提出了一些综合防治方法,为我省农业工作者在田间识别及防治该病提供参考。     

甜高粱特性及河北省研究利用现状

描述了甜高粱的生物学特性,对河北省甜高粱的育种和产业化状况进行了分析,并针对存在的问题,提出了合理化建议.这对于河北省发展甜高粱产业有一定的现实意义.