红肉蜜柚 PDR 型转运蛋白基因的发掘及 CmPDR11-2 表达与耐草甘膦初步分析

基于红肉蜜柚 RNA-seq 数据库,筛选出 50 个 ABC 转运蛋白家族基因,其中包含 11 条 PDR 型基因。对11 条柚 PDR 基因进行命名和生物信息学分析。同源性分析结果表明：CmPDR11-2 编码的氨基酸序列与拟南芥中转运百草枯除草剂的 AtPDR11 基因同源性最高,达 69.25%,利用 RT-PCR 技术克隆得到 CmPDR11-2 的 ORF 序列。该序列长度为 4 371 bp,编码一个含有 1 456 个氨基酸的蛋白质,分子量 165.138 03 ku,该蛋白属于稳定的亲水性蛋白,无信号肽,具有 12 个跨膜结构,定位于细胞膜。实时荧光定量 PCR 结果表明,草甘膦除草剂胁迫处理条件下,1~15 d 处理组柚叶的 CmPDR11-2 基因相对表达量呈整体上升趋势,且均高于对照组,反应迅速且持久,这表明 CmPDR11-2 基因表达与红肉蜜柚耐草甘膦有关。     

Deep‐sequencing revealed Citrus bark cracking viroid (CBCVd) as a highly aggressive pathogen on hop

Newly emerging or re‐emerging diseases are a constant and significant threat to agricultural production, so prompt and accurate identification of the causative agents is required for rapid and appropriate disease management. Classical methods of pathogen detection can be successfully supplemented by next‐generation sequencing (NGS), whereby sequence analysis can help in the discovery of new or emerging diseases. In 2007, hop growers in Slovenia reported the appearance of severely stunted hop plants, a phenomenon that spread rapidly within hop gardens and among farms. Classical diagnostic methods were unable to detect a new pathogen; therefore, single step high‐throughput parallel sequencing of total RNA and small RNAs from plants with and without symptoms was employed to identify a novel pathogen. The sequences were assembled de novo and also mapped to reference genomes, resulting in identification of a novel sequence of Citrus bark cracking viroid (CBCVd) in the stunted hop plants. Furthermore, the presence of this novel pathogen on hop was confirmed by RT‐PCR analysis of 59 plants with symptoms from 15 hop gardens, representing the main outbreak locations identified by systematic disease monitoring, and small RNA Illumina sequencing of the bulked RNA sample. The high infectivity of the newly identified CBCVd was also confirmed by biolistic inoculation of two hop cultivars, which developed aggressive symptoms in controlled conditions. This study shows the feasibility of deep sequencing for the identification of causative agents of new diseases in hop and other plants.     

早熟柑橘黄龙病空间格局参数特征及其应用

为了揭示柑橘早熟宫川黄龙病的空间分布信息和病株行为特征,2004-2009年采取多级抽样法于每年11月上旬在果实成熟期对2块定点样地逐株进行病级调查,取得了12组样本资料,应用聚集度指标法、Iwao 法和Taylor法等对其空间分布型进行测定检验,结果表明柑橘黄龙病在早熟宫川果园呈聚集分布,其聚集强度是随着病级升高而增加。其聚集原因经Blackith种群聚集均数测定,当m<2.1184时,其聚集是由于某些环境如气候、栽培条件、植株生育状况等所引起的;当m≥2.1184时,其聚集是由病株本身的聚集行为与环境条件综合影响所致。在此基础上提出了理论抽样数和序贯抽样模型：n=(1/D)2?[1/m+0.6761] 和Tn=1.831 /[D02-0.1581 /n]。     

除草剂胺磺灵(Oryzalin)诱导椪柑四倍体的研究

以椪柑枝条为外植体,建立其无菌离体快繁体系,利用除草剂Oryza1in为诱变剂进行椪柑四倍体诱变处理,研究胺磺灵Oryzalin不同浓度和不同处理时间对椪柑四倍体诱导效果的影响,结果表明:椪柑四倍体诱导的最佳处理条件为40 mg/L浓度的Oryzalin浸泡茎段2d,诱导率最高为13.3％.     

生防细菌1505的鉴定及其对采后柑橘炭疽病的抑制效果

采用细菌学方法及分子生物学技术对菌株1505进行鉴定,并对其在防治采后柑橘炭疽病上的效果进行研究.结果显示,菌株1505对柑橘炭疽病菌具有拮抗活性,其活菌悬浮液在PDA平板上对柑橘炭疽病菌产生明显抑制作用,而灭菌发酵液和去除菌体的发酵液均无抑菌效果;连续8次在人工培养基上转代培养,菌株1505对柑橘炭疽病菌生长的抑制力没有发生明显改变;菌株1505对胶孢炭疽菌[Colletotrichum gloeosporioides(Penz.)Sacc.]引起的柑橘炭疽病有明显的防治作用,刺伤接种的防效为48.8%,自然发病的防效为46.3%.根据形态学特征和生理生化反应,结合16SrDNA序列分析结果,将菌株1505鉴定为枯草芽孢杆菌(Bacillus subtilis).     

杀菌剂和煤污消除法对柑橘煤烟病的防治效果

在室内采用菌丝生长法筛选出50%多菌灵WP、70%甲基硫菌灵WP和80%代森锰锌WP 3种对柑橘煤烟病菌菌丝生长具有较强抑制作用的杀菌剂,进一步对这3种杀菌剂和新增2种煤污消除剂(柴油乳剂200~250倍液和面粉10~12倍液)进行了大田药效试验。结果表明:50%多菌灵WP 500倍液的防治效果最好,70%甲基硫菌灵WP 1 000倍液次之,柴油乳剂200~250倍液与80%代森锰锌WP 500倍液防治效果相当。     

柑橘园柑橘小实蝇入侵扩散规律与危害动态模型研究

为了探索柑橘小实蝇入侵扩散与危害规律,提高其监测与防控水平,2008—2010年应用柑橘小实蝇专用性诱剂和诱捕器,在全市19个镇(街道)35个柑橘园建立监测点进行全市性入侵扩散分布普查;在古城伏龙柑橘园和市区水果市场,建立2个系统监测点开展全年种群数量消长监测,结果表明柑橘小实蝇种群入侵扩散与时空分布呈塔型趋势,即以城区为中心,并呈向周边区域扩散蔓延趋势;全年种群时序数量变化主要呈单峰型曲线变化,一般于6月中下旬至7月上中旬初见性诱成虫,8月上旬形成增长拐点,9—10月形成数量高峰,影响种群数量消长的主要因子有种群基数、气候和生境条件等,从而创建柑橘小实蝇基数(m6)与全年种群诱量(M)关系模型M=23.8339m6+59.8003(n=6,r=0.9735**)、当旬虫口密度(mn)与其前3个月的旬平均气温(tn-9)关系模型mn=1.9248tn-9-14.88063(n=72,r=0.5123**),以及柑橘挂果期成虫诱量(M)、有虫株率(R%)、有虫果率(P%)、每虫果幼虫量(N)等关系模型:R=0.3667M-1.2746(n=11,r=0.8901**);P=0.0581R+0.3112(n=11...     

柑橘园柑橘小实蝇入侵扩散规律与危害动态模型研究

为了探索柑橘小实蝇入侵扩散与危害规律,提高其监测与防控水平,2008-2010年应用柑橘小实蝇专用性诱剂和诱捕器,在全市19个镇（街道）35个柑橘园建立监测点进行全市性入侵扩散分布普查;在古城伏龙柑橘园和市区水果市场建立2个系统监测点开展全年种群数量消长监测,结果表明柑橘小实蝇种群入侵扩散与时空分布呈塔型趋势,即以城区为中心,并呈向周边区域扩散蔓延趋势;全年种群时序数量变化主要呈单峰型曲线变化,一般于6月中下旬至7月上中旬初见性诱成虫,8月上旬形成增长拐点,9-10月形成数量高峰, 影响种群数量消长的主要因子有种群基数、气候和生境条件等,从而创建柑橘小实蝇基数（m6）与全年种群诱量（M）关系模型M=23.8339 m6+59.8003（n=6, r=0.9735**）、当旬虫口密度(mn)与其前3个月的旬平均气温(tn-9)关系模型mn=1.9248tn-9-14.88063（n=72, r=0.5123**）,以及柑橘挂果期成虫诱量（M）、有虫株率（R%）、有虫果率（P%）、每虫果幼虫量（N）等关系模型：R=0.3667M-1.2746（n=11, r=0.8901**）;P=0.0581R+0.3112（n=11, r=0.9649**）;N=0.6438P+0.9610（n=11, r=0.7000*）。应用柑橘小实蝇种群入侵扩散危害规律及其参数模型,可反映柑橘园柑橘小实蝇发生变化动态,可随旬作出预报和决策防治,这对提高其监测预警和持续控制具有重要指导意义。     

柑桔转基因研究进展

柑桔基因工程育种因其具有周期短、效率高、可控性强等优点而成为柑桔育种的重要内容之一。本文就柑桔转基因研究的品种及外植体、柑桔转基因研究所采用的方法、导入柑桔的外源基因进行了综述,最后提出了柑桔遗传转化中存在的问题并对柑桔转基因研究进行了展望。     

Study of force distribution in the citrus tree canopy during harvest using a continuous canopy shaker

Mechanical harvesting is increasingly being employed in the citrus industry of Florida because of the faster and efficient harvesting it provides with comparatively lower cost when compared to manual harvesting. Continuous canopy shakers are the only mechanical harvesters commercially used in Florida. The main concerns regarding the use of these machines are damage to tree and detrimental effect on next year yield. Because of these concerns, only a very low percentage (6-7%) of the acreage is being harvested mechanically. To improve these machines and address the growers’ concerns, experiments were conducted to study the force and acceleration distribution on the tree branches and fruits. The acceleration was measured at different locations in the canopy using tri-axis accelerometers attached to the branch and data was recorded using ZigBee^® transceivers. The distribution of force and acceleration along an individual branch in trees of two different sizes were studied at three different tine angles and frequencies of the shaker. Both distributions were modeled using the Curve Fitting Toolbox™ of Matlab^®. The results suggested that the force was higher for the fruits inside the canopy than the ones at the edges. It was also observed that the maximum force required to remove the fruit mechanically was only 18% of the traditionally measured fruit detachment force. The force along the branch was found to be Gaussian in nature and the acceleration along the branch was found to be exponential.