基因组测序技术解析耐除草剂转基因水稻G2-7的分子特征

Molecular characterization, such as copy number and flanking sequence of foreign DNA fragment insertion site, is the important identity information, provided during safety assessment of genetic modified crop. In this study, the T-DNA insertion site, copy number and flanking sequences were identified in transgenic glyphosate-tolerant rice G2-7 based on whole genome sequencing in combination bioinformatics analysis method. 47.13 Gb clean sequence data for G2-7 was generated on Illumina NovaSeq 6000 platform. The junction reads mapped to boundaries of T-DNA and flanking sequences in G2-7 were identified by comparing with sequence of transformation vector and rice reference genome. The results showed that exogenous T-DNA fragments was integrated in the position of Chr. 1 36,189,491-36,189,507 with a single copy, 16 bp rice genome sequence was deleted at the insertion site and no insertion of vector backbone. 375 bp and 353 bp flanking host DNA sequence of 5′-end and 3′-end of the insertion DNA fragment were also obtained, respectively. The putative insertion location and flanking sequences were further confirmed by PCR amplification and Sanger sequencing. The results not only provided data support for safety assessment and event specific detection, but also demonstrated that WGS was an effective technique for identifying molecular characterization in rice.     

棉花GbSTK基因调控开花和黄萎病抗性的功能研究

Cotton is an important cash crop, and achieving disease resistance as well as early maturity is an important breeding goal. However, the molecular relationship between disease resistance and early maturity of cotton is still a research gap. In previous study, we identified a GbSTK gene response to V. dahliae that could enhance Verticillium wilt resistance in transgenic Arabidopsis. In this study, we found that GbSTK was more highly expressed in resistance and/or tolerant varieties than in susceptible varieties. Knocking down of GbSTK expression in Nongda 601 showed that the silenced plants displayed serious disease symptoms, with disease index from 27.5 (tolerant) to 63.2 (susceptible), suggesting that GbSTK positively regulates cotton Verticillium wilt resistance. More interesting, we found that GbSTK could promote the development of Arabidopsis. At the flowering time point, the average number of rosette leaves in transgenic lines was 7.5, significantly less than the mock plants, and the transgenic plants bloomed five to seven days earlier than the control. The FT and SOC1 gene, regarded as marker genes in Arabidopsis flowering signaling pathway, maintained higher expression level in transgenic lines than in the mock, indicating that GbSTK could accelerate flowering via regulating FT and SOC1 gene expression. We also obtained 30 candidate proteins that could interacted with GbSTK via yeast double hybrid test, which helped to further revealing the molecular regulatory network of GbSTK. Taken together, we first identified a functional gene that could improve disease resistance and early flowering, which would provide a reference for genetic improvement of cotton disease resistant and early maturity.     

小麦粒重降低原因与防御对策研究

通过试验和调查研究,对１９９８年小麦粒重降低原因进行了分析。结果表明,厄尔尼诺现象造成气候条件的异常是粒重普遍降低的基本原因;麦蚜为害是粒重大幅度降低的重要原因;而品种的综合抗性差以及栽培管理不及时更是其主要原因。重视培养地力,选用综合抗性强的小麦品种,抓好中后期追肥、浇水管理和加强病早防治等,是保证小麦获得高而稳的粒重,实现小麦持续增产增收的战略性措施。     

朝阳丘陵山区农业机械化发展研究

朝阳丘陵山区农业机械化发展程度较低,造成全市农机化发展不均衡.介绍朝阳地区的地形与气候特征,分析丘陵山区机械化发展现状及影响因素,阐述丘陵山区发展农业机械化的思路与原则,并提出适宜的发展建议,以促进朝阳丘陵山区农机化水平的提高.     

拖拉机多路液压输出功率试验台测控技术研究

介绍多路液压输出功率试验台的系统构成、软件设计、特点与创新之处。该试验台的目的在于提供一种分流量区段、计算机系统实现自动加载与实时测试和处理的试验设备,主要测定农业拖拉机与机具连接处的液压动力输出装置上液压压力、流量和最大有效液压输出功率。     

基于探地雷达的田块尺度下不同深度土壤含水量监测

为确定田块尺度下探地雷达对不同深度及相邻反射层间土壤含水量的反演精度、有效反演深度、最佳反演深度及最优反演模型,本研究采用1000 MHz中心频率探地雷达设备,分别在无降雨偏干旱土壤和降雨后湿润土壤两种条件下,在选定农田区域基于共中心点法采集雷达波数据,提取有效地表波与反射波数据,通过双曲线拟合法分别获取不同深度反射层...     

栅条滚筒式红枣分级机改进与试验研究

为了保证红枣分级过程中不伤果,通过对传统的等螺距螺旋红枣分级机的改进与试验,确定较优的螺距及转速。采用二因素三水平的正交试验,研究了不同螺旋螺距和滚筒转速下对红枣混级率和生产效率的影响,得到内螺旋螺距变化影响较为显著。通过均匀试验得到改进后红枣分级机的主要参数为内螺旋螺距为40mm、滚筒转速为32r/min时分级质量和效率最好。     

施肥和水分调亏对冬小麦生长和产量的影响

通过盆栽试验对不同施肥处理条件下冬小麦水分调亏效应进行了研究。设置3个施肥处理:不施肥(F0)、施复合肥(F1)和复合肥+有机肥配施(F2);2个水分处理:充分供水(W:75%FC)和水分调亏(D:50%FC～55%FC)。研究表明,在孕穗期,相同施肥条件下,调亏处理冬小麦的叶面积、株高和叶绿素均显著小于未调亏处理。到花期时,各水分调亏处理的叶绿素量与未调亏没有显著差别。F2处理的水分调亏小麦的叶面积和株高与未调亏小麦没有显著差别;F0和F1处理的水分调亏小麦的叶面积和株高均显著小于相应未调亏处理小麦。在拔节期,F0处理的水分调亏小麦的光合速率显著低于未调亏处理;F1和F2处理的水分调亏小麦的光合速率与未调亏处理没有显著差异。但复水后,到抽穗期,F2处理的水分调亏小麦的光合速率显著高于未调亏处理,表现超补偿效应。但F0和F1处理的水分调亏小麦的光合速率和未调亏小麦相比没有显著区别。抽穗后在充分供水条件下,F0和F1处理的小麦,返青-拔节期水分调亏对产量有显著负效应。F2的调亏处理小麦的产量没有受到影响;在干旱条件下,F0和F1处理的小麦,返青-拔节期水分调亏对产量没有影响,但F2处理的水分调亏小麦的产量显著高于未调亏处理的小麦。在相同施肥条件下,水分调亏处理小麦的稳产性均高于未调亏处理小麦。在各调亏处理中,F2处理小麦的稳产性最高,F1处理小麦次之,F0处理小麦的稳产性最低。     

我国农田总氮流失影响因素分析

利用第一次全国农业污染源普查的70个样本数据,对农田非点源污染总氮（TN）流失系数与6个影响因素间的关系进行相关和回归分析。结果表明,土地利用方式X3、土壤质地X4、施氮量X5、年降雨量X64个因素对农田TN流失系数有显著影响。由标准化回归系数得知,各因素对流失系数影响的大小顺序为X6〉X5〉X3〉X4。在此基础上所建立的我国农田TN流失系数的回归方程为Y=-5.3＋0.28X6＋0.017X5＋4.563X3＋0.088X4,通过16个文献数据对该模型进行验证,结果显示该模型具有很好的预测能力,可用于我国不同地域农田TN流失系数的估算。     

青岛市1990-2011年土地利用/覆被变化研究

基于青岛市1990,2000,2006年LandsatTM影像和2011年‘HJ-1’卫星影像,采用土地利用动态变化模型,分析了青岛市1990-2011年土地利用/覆被变化(LUCC)情况.结果表明,21 a间青岛市土地利用状况变化显著.(1)耕地、草地面积减少,城乡、工矿、居民用地增加,林地面积先减少后增加,水域和未利用土地则呈现先增加后减少的态势;(2)青岛市土地利用程度逐年提高,说明青岛市正处于土地利用发展时期,土地利用集约度将进一步提高;(3)空间上,中部和东部地区变化显著,北部和西南部变化相对较小.土地利用变化类型转换关系复杂,主要向城乡、工矿、居民用地转化.