马铃薯生产全程机械化技术推广实践与思考

介绍了马铃薯生产过程及机械化技术,并以重庆市马铃薯全程机械化技术推广实践为例,总结了实施情况,分析了存在的问题,提出了发展建议。      

聚L-乳酸改性麦草共混物材料的研究

以聚L-乳酸(PLLA)和麦草(WS)为原料,以N-甲基吗啉-N-氧化物(NMMO)为溶剂,采用溶液共混法制备了PLLA/WS共混物。首先将麦草溶解在NMMO后,再添加聚L-乳酸并溶解,制备聚L-乳酸与麦草的共混溶液。共混溶液采用浇膜法制备PLLA/WS共混物,采用差示扫描量热法、X射线衍射法、傅里叶变换红外光谱、热重分析和扫描电镜等方法对所得的共混物进行表征。结果表明,聚L-乳酸与麦草可以形成均匀的共混溶液。共混物中PLLA与麦草组分之间具有较强的相互作用,相容性较好。当共混物中PLLA的质量分数为50%时,共混物可以形成结晶结构,且随着PLLA含量的增加,其结晶更加完美,熔点与热稳定性提高。共混物薄膜断面结构较为致密,这说明PLLA与麦草相容性较好,混合均匀。通过调节聚L-乳酸和麦草的配比,可以制备不同性能的生物高分子材料。     

开阳县田坝渔业小区实施大鲵养殖的技术措施

为摸索名优水产品养殖经验,加快我县水产养殖结构调整,促进我县渔业健康发展,2007年,我县申报实施了《贵阳市社会主义新农村基础设施建设——养殖基地基础设施建设——渔业小区建设》项目,在花梨乡翁昭村田坝组模拟大鲵生态生活习性新建了100口养殖池的大鲵小区,修建了养殖房、管理房、配套饵料鱼池、饵料鱼暂养池、引水管道等基础设施和配套设施,并于2008年3月25日起引种入场养殖。现将1年来小区开展大鲵人工养殖的技术措施报告如下。     

磷化氢熏蒸对桔小实蝇氧化代谢体系的影响研究

为阐明磷化氢的生化毒理机制,本试验以重要检疫性害虫桔小实蝇(Bactrocera dorsalis Hendel.)为试虫,研究了25℃下磷化氢熏蒸对桔小实蝇3龄幼虫的毒力以及磷化氢熏蒸不同时间对桔小实蝇3龄幼虫氧化代谢体系的影响。结果显示：（1）25℃条件下磷化氢熏蒸桔小实蝇3龄幼虫48 h的LD50、LD90、LD99分别为0.28、0.37、0.46 mg/L;（2）磷化氢熏蒸抑制了桔小实蝇的呼吸作用;（3）随熏蒸时间延长,桔小实蝇体内过氧化氢含量和脂质过氧化水平不断上升,氧化压力逐渐增加;（4）磷化氢抑制了过氧化氢酶活性,最大抑制率为55.99%,增强了过氧化物酶活性、超氧化物歧化酶活性及抑制羟自由基能力,最大提高率分别为141.48%、130.21%、155.90%。本研究确认了磷化氢熏蒸杀灭桔小实蝇的有效性,其作用机制可能是通过抑制过氧化氢酶活性进而加剧活性氧积累实现的。     

泰国政府投巨资收储农产品

以三色竹芋的侧芽为外植体,研究了三色竹芋不定芽诱导、增殖和生根的组织培养过程,并研究了6-BA浓度和继代次数对叶片颜色的影响。结果表明：以三色竹芋的侧芽为外植体,经过芽的分化、增殖和生根可获得批量组培苗;降低6-BA的浓度,减少继代次数,有利于保持叶片的颜色。     

The protein,non-protein and total nitrogen inSolanum tuberosum,ssp.andigena potatoes

Total protein estimated from 80% ethanol insoluble nitrogen in residue ofS. tuberosum, ssp.andigena tubers agreed well with results obtained by Potty method and estimation of non-dialyzable nitrogen. The method is simple, rapid and applicable for screening large numbers of samples. Dry matter, total nitrogen, protein nitrogen and non-protein nitrogen were analyzed for 50 clone samples harvested in Huancayo, Peru, and correlations between the various constituents are statistically analyzed and discussed. An increase in total nitrogen with an increase of protein nitrogen was observed. Clones with higher dry matter normally showed lower % of non-protein nitrogen. The percentage of protein nitrogen to total nitrogen varied from 40 to 74% in the 50 clone samples and clonal differences in protein production were evident.     

数字乡村发展的实践与探索——基于北京的调研

研究旨在通过分析北京市数字乡村建设实践,发现存在问题,找出推进路径,为数字乡村发展提供可借鉴经验.利用文献分析、典型案例和专家咨询法,探讨数字乡村发展理论与实践.数字化是现代农业4.0阶段的关键特征,数字经济是农业农村高质量发展的新引擎、新动能.北京是数字乡村发展的先行者,为北京乡村振兴和农业现代化建设打下了坚实基础....     

Relationship between stable carbon isotope discrimination and water use efficiency under regulated deficit irrigation of pear-jujube tree

To investigate the relationship between stable carbon isotope discrimination (Δ) of different organs and water use efficiency (WUE) under different water deficit levels, severe, moderate and low water deficit levels were treated at bud burst to leafing, flowering to fruit set, fruit growth and fruit maturation stages of field grown pear-jujube tree, and leaf stable carbon isotope discrimination (Δ_L) at different growth stages and fruit stable carbon isotope discrimination (Δ_F) at fruit maturation stage were measured. The results indicated that water deficit had significant effect on Δ_L at different growth stages and Δ_F at fruit maturation stage. As compared with full irrigation, the average Δ_L at different growth stages and Δ_F at fruit maturation stage were decreased by 1.23% and 2.67% for different water deficit levels, respectively. Δ_L and Δ_F among different water deficit treatments had significant difference at the same growth stage (P < 0.05). Under different water deficit conditions, significant relationships between the Δ_L and WUE_i (photosynthesis rate/transpiration rate, P_n/T_r), WUE_n (photosynthesis rate/stomatal conductance of CO_2, P_n/g_s), WUE_y (yield/crop water consumption, Y/ET_c) and yield, or between the Δ_F and WUE_y and yield were found, respectively. There were significantly negative correlations of Δ_L with WUE_i, WUE_n, WUE_y and yield (P < 0.01) at the fruit maturation stage, or Δ_L with WUE_i and WUE_n (P < 0.01) over whole growth stage, respectively. Δ_F was negatively correlated with WUE_y, WUE_n and yield (P < 0.05), but positively correlated with ET_c (P < 0.01) over the whole growth stage. Thus Δ_L or Δ_F can compare WUE_n and WUE_y, so the stable carbon isotope discrimination method can be applied to evaluate the water use efficiency of pear-jujube tree under the regulated deficit irrigation.