Attempts to eliminate <Emphasis Type="Italic">Candidatus</Emphasis> phytoplasma phoenicium from infected Lebanese almond varieties by tissue culture techniques combined or not with thermotherapy

Elimination of Candidatus phytoplasma phoenicium from two infected Lebanese varieties of almond by using different tissue culture techniques is reported. Except for the oxytetracycline therapy which totally inhibited the development of explants, stem cutting cultures associated with thermotherapy, shoot tip cultures associated or not with thermotherapy, and shoot tip micrografting were all suitable, either for shoot regeneration or for elimination of phytoplasma from the two varieties. However, stem cutting culture coupled with thermotherapy seemed to be the most effective for regeneration of phytoplasma-free plantlets.     

植物菌原体检测技术

回顾了植物菌原体的检测从早期的电镜观察,到现在应用分子生物学技术测定的发展历史,概述了各种检测技术的基本原理和特点,以及我国在这个领域的研究现状.     

陕西清涧县枣疯病发生和危害调查及防治建议

根据对陕西清涧县枣疯病发生特点和危害状况进行调查和分析,提出了把好种苗带菌关、积极预防介体叶蝉传病、稳步地开展枣疯病治疗试验和示范、坚持因地适时清除病株或修除病枝,正确处理好枣果产量与枣疯病防治的关系等具体病害防治措施,以及黄土高原地区枣疯病综合治理原则。     

Transmission of Rhus (Rhus javanica L.) Yellows by Hishimonus sellatus and Host Range of the Causal Phytoplasma

In 1998, rhus (Rhus javanica L.) yellows (RhY), caused by phytoplasma, was found in Miyagi Prefecture, Japan. In vector transmission tests, Hishimonus sellatus acquired RhY phytoplasma from diseased R. javanica and transmitted it to healthy R. javanica. Twenty-two species of herbaceous plants in 10 families were infected with RhY phytoplasma by H. sellatus. The host range and main symptoms on test plants of RhY phytoplasma differed from those of Macrosteles striifrons-transmitted phytoplasmas, which belong to the same 16Sr I group phytoplasma. Received 6 December 1999/ Accepted in revised form 14 May 2000     

超速离心结合Real-time PCR分离纯化枣疯病植原体DNA

分离纯化枣疯病植原体基因组DNA,有助于进一步开展对此病原全基因组测序的研究,CTAB法提取枣疯病叶片的总DNA后,采用氯化铯双苯酰亚胺密度梯度离心法从枣树总DNA中富集纯化枣疯病植原体DNA,并通过Real-time PCR方法对分离纯化效果进行定量检测。在此基础上,探索了不同CsCl初始密度对DNA分离效果的影响。在20℃,初始密度为1.650 0g/cm3,经206 000×g下离心23h后,感染枣疯病样品(IS)的离心管中出现2条DNA亮带,正常枣树样品(NS)离心管中只有1条。Real-time PCR检测结果表明NS管中的条带为枣树基因组DNA;IS管中与NS管中相同位置的条带为枣树基因组DNA,另1条带为枣疯病植原体基因组DNA。在保留其他试验条件下,不同CsCl初始密度,会影响DNA条带的位置,也会影响枣疯病植原体DNA与枣树DNA的分离效果,在1.562 2g/cm3的初始浓度下分离效果最好。采用超速离心法可以有效地从感染枣疯病的枣树中分离得到纯的枣疯病植原体DNA,同时利用Real-time PCR法可以实现分离效果的评价,利用此方法分离得到的DNA可用于枣疯病植原体的全基因组测序。     

北京怀柔区板栗黄化皱缩病害调查

在怀柔板栗主要产区对中国板栗黄化皱缩病进行了2 a的系统调查,结果为发病村占94.7%2,009年和2010年发病地块依次为34.6%和35.7%,发病株分别为3.58%和3.77%,平均病情指数分别为0.0147和0.0149。病害分为发病初期、发病盛期、滞留期、稳定期和落叶期5个阶段,用PCR扩增16S rRNA基因检测植原体,检出率81.2%;在感病板栗林内采集到蝽类、叶蝉和栗斑蚜共11种刺吸式昆虫。     

槟榔黄化病病原研究及防控中存在的问题及展望

槟榔黄化病是一种由植原体引起的毁灭性病害,现已成为严重制约中国海南槟榔产业健康发展的瓶颈.本文详细介绍了黄化病病原研究方面的进展并分析了存在的问题和争议,归纳了防控中存在的问题;预测了中国槟榔产业发展前景及槟榔黄化病发展趋势,进而对政府、科研院所、高等院校、企业和农户5方提出了建议.最后,对槟榔黄化病治理作了展望.     

两种林木植原体病害的分子鉴定

近年来, 林木植原体病害发生日趋严重, 对我国林业经济和生态造成了很大损失。2021年-2022年, 在山西沙棘主产区的沙棘上和北京冬奥园区的油松上分别出现了典型的植原体病害症状;沙棘叶片皱缩, 呈小叶状;油松过度分枝生长且出现球状结构等。本研究通过荧光显微观察, 16S rRNA和tuf基因序列分析, 并结合虚拟限制性片段长度多态性分析证实了这两种病害均由植原体引起。基于16S rRNA的系统进化分析显示:引起沙棘叶片皱缩的植原体与泡桐丛枝植原体(Paulownia witches’-broom phytoplasma, OP107515.1)的相似性最高(99.92%), 引起油松丛枝的植原体与狗尾草丛枝植原体株系(Setaria viridis witches’-broom phytoplasma, FJ263625.1)的相似性最高(99.52%);基于tuf基因的系统发育树显示, 二者同属于16SrⅠ组D亚组(16SrⅠ-D)。本研究首次明确了沙棘叶片皱缩病和油松丛枝病相关植原体的分类地位, 为这两种植原体病害的准确诊断、快速检测及其防治提供了基础资料。     

Phytoplasma transmission by in vitro graft inoculation as a basis for a preliminary screening method for resistance in fruit trees

In vitro grafting was tested as a technique for inoculating Prunus rootstock Prunus marianna GF 8-1 with European stone fruit yellows (ESFY) phytoplasmas and apple rootstock Malus pumila MM106 with apple proliferation (AP) phytoplasmas. In vitro shoot cultures of ESFY-infected Prunus marianna GF 8-1 and AP-infected Malus pumila MM106 were used as graft inoculum to transmit the phytoplasmas to the respective healthy rootstock. Phytoplasma transmission was assessed after a graft contact of 1, 2 or 3 months. Healthy autografts were used as controls to monitor parameters of in vitro grafting. Successful graft union formation ranged from 58 to 79% irrespective of the plant species and the sanitary state of the graft. Pathogen-specific polymerase chain reaction (PCR) was used to test the inoculated rootstocks for the presence of ESFY and AP phytoplasmas, respectively. The rate of ESFY phytoplasma transmission in successful Prunus -grafts increased from 69 to 94% with the time of contact. AP phytoplasma transmission to Malus occurred in 80 to 97% of successful grafts. To our knowledge this is the first report of phytoplasma transmission by grafting in vitro . The results provide a good basis for the establishment of a preliminary in vitro screening method for phytoplasma resistance in Prunus and Malus .     

基于Maxent的椰子致死性黄化植原体在中国的适生性分析

利用Maxent生态位模型和Arc GIS软件,并结合椰子树(以下简称椰树)在中国的种植分布,对椰子致死性黄化植原体在中国及中国椰树种植区的适生性进行了预测。结果表明:中国主要的椰树种植区均为椰子致死性黄化病的潜在适生区,其中华南沿海地区及海南大部分地区属于中风险区和高风险区。经ROC曲线分析法验证,Maxent模型的AUC值为0.992,表明预测结果具有较高的可信度。