水稻幼穗与Ustilaginoidea virens互作早期的转录组分析

 由子囊菌门真菌稻绿核菌Ustilaginoidea virens引起的稻曲病是世界范围内水稻生产上的重要病害之一。但是,对水稻抗稻曲病的抗性机制仍不清楚。为初步探明水稻与稻曲病菌之间互作早期的分子调控机制,本研究采用比较转录组测序技术对稻曲病菌接种抗病品种‘IR28’和感病品种‘两优培九’(LYP9)6 h的测序数据进行了分析,试图初步阐明水稻抗病分子机制。分析发现,在抗病和感病品种中均差异表达基因有1 005个共表达,在这些基因中,抗病品种中表达上调基因(697个)多于感病品种中表达上调的基因(626个),下调的基因(308个)少于感病品种中下调表达的基因(379个);随后通过GO富集和KEGG代谢途径分析,发现苯丙烷类代谢途径和双萜植保素合成途径相关的基因、几丁质酶、β-1,3-葡聚糖酶、糖基水解酶和过氧化物酶等基因在抗病品种中被显著诱导上调表达,而在感病品种中基因表达低于抗病品种或下调表达,推测这些基因很可能在水稻与稻曲病菌识别早期发挥重要的抗病作用。该研究结果可为水稻抗稻曲病基因克隆及抗稻曲病分子育种提供理论基础。     

杧果大茎点菌(Macrophoma mangiferae)在果肉中子实体发育特性的研究

 杧果大茎点菌Macrophoma mangiferae Hingoroai et Sharma是引起广西杧果象牙品种果腐病的病原菌之一。对杧果大茎点菌和罹病果肉组织,运用病理组织解剖方法,观察到杧果大茎点菌M . mangiferae的子实体在果肉组织中生长发育过程,需经过营养菌丝集结、菌丝球中心组织细胞分化、雏形分生孢子器形成、分生孢子器产生和释放分生孢子等4个阶段。此项研究结果揭示了该类病原菌子实体细胞学发育特点及致病机理。     

4种杀菌剂对杧果采后病害的控制效果

采用生长速率法测定了4种杀菌剂对果炭疽病菌和果蒂腐病菌的抑制作用。结果显示:咪鲜胺.异菌脲对炭疽菌的毒力最高,EC₅₀和EC₇₅分别为0.12μg/mL和0.27μg/mL、其次为咪鲜胺。而与果炭疽病菌相比,4种杀菌剂对果蒂腐病菌生长影响差异并不明显,异菌脲对蒂腐病菌的毒力较高,EC₅₀和EC₇₅分别为0.35μg/mL和0.82μg/mL。采后病害防治试验表明,267μg/mL咪鲜胺.异菌脲常温浸果3～5 min,贮藏15 d,对炭疽病的防效达91.07%,防治效果最佳。供试4种杀菌剂对蒂腐病有一定的抑制作用,但仅有1 250μg/mL异菌脲常温浸果1 min对蒂腐病的防效显著高于对照。经综合评价,咪鲜胺.异菌脲对控制果采后病害发生效果最好。     

水稻品种与水稻细菌性条斑病菌的互作机制

水稻叶片接种3d后，水稻细菌性条斑病菌开始在叶片上大量增殖；接种10d后，病菌数量开始保持相对的稳定，但感病品种上的菌量比抗病品种上的菌量在10倍左右，病斑在接种后第3d开始出现，接种10d以后，病斑在感病品种上能继续快速发展，而在抗病品种上开始受到抑制，通过对抗病和感病品种叶片上的气孔观测发现，感病品种的气孔密度和气孔长度一般都较抗病品种大，相关分析表明，气孔长度理发师品种抗性相关。接种后对PAL酶的活性测定结果表明，PAL酶的活性与品种抗性呈负相关关系。     

植物与病原物互作中的生物膜研究

生物膜是一种附着于生命或非生命物体表面的有特殊结构和功能的微生物群落。它广泛地存在于自然界和人工环境中。本文对细菌生物膜的定义、形成过程、影响因素、抗性机制以及在植物与病原物互作中的研究作了简要综述。     

青海云杉响应锈菌侵染转录组分析

为探究锈菌与青海云杉之间的互作机制,利用Illumina测序平台对青海云杉健康植株和发病植株进行转录组测序,以差异倍数(FC)≥2且错误发现率(FDR)<0.01为标准,共获得15408个差异表达基因,有10296个差异基因上调,5112个差异基因下调。GO注释中,DEGs显著富集到代谢过程、细胞过程、催化活性和结合等过程。KEGG注释中,DEGs显著富集到核糖体、植物与病原互作、内质网蛋白加工、信号转导等过程,通过分析相关通路发现,青海云杉响应锈菌侵染的分子机制受多基因网络系统的调控。为验证RNA-seq数据的可靠性,对10个DEGs进行RT-qPCR表达量检测,验证结果为,RT-qPCR和RNA-seq测得的基因表达趋势基本一致。这有助于深入研究候选基因在青海云杉响应锈菌侵染中的作用,同时也为开展青海云杉抗病功能基因组学研究奠定基础。     

一种危害杧果幼果的瘿蚊科害虫

杧幼果普瘿蚊(Procontarinia frugivora Gagné)是目前已知唯一危害杧果果实的地区性害虫,国内尚未发生分布。本文综述了其分类地位、地理分布、成虫形态特征、生物学特性、传播途径等,讨论了其经济重要性及防治对策,提出了进境检疫鉴定方法,以期为进境检疫工作提供参考。     

木霉-植物互作机制的研究进展

木霉作为是一种重要的生防制剂已经成为化学农药替代化和减量化的主要产品,也是公认的最有前防治病害的目的。随着木霉-植物互作研究的深入,关于互作机制方面的研究已取得了明显的进展。木霉与植物的互作过程包括木霉对植物的感知、木霉在植物体表和体内的定殖并引起植物的一系列变化等复杂的过程,本文重点对木霉-植物互作过程中木霉在植物中的定殖、木霉和植物的生理生化变化以及激素信号传递模式进行综述,以明确木霉促进植物生长和防治植物病害的机理,明确木霉与植物的互作机制对进一步提高木霉的生防效果、扩大木霉的应用具有重要的意义。     

小麦与小麦秆锈菌互作及非亲和机制研究

 本论文选用以中国春(Chinese Spring)为背景的小麦抗秆锈病近等基因系,与我国小麦秆锈菌3个主要生理小种,组成完全非亲和性互作ISr5-Ra/21C₃ CKR (Sr5/P5,侵染型0)、高度非亲和性互作ISr11-Ra/34M KG (Sr11/P11,侵染型0)及中度非亲和性互作ISr6-Ra/34C₂ M FR (Sr6/P6,侵染型1,2),对各类型互作对秆锈菌生长发育的影响、互作中重要酶系活性及同功酶组成、重要生化组分含量变化规律及它们在互作中的可能作用进行了研究。并比较了所用小麦近等基因系及秆锈菌致病型间可溶性蛋白含量和种类、重要酶系活性和同功酶组成的差异,对基因组DN A限制性片段长度多态性进行了研究。     

杧果炭疽菌拮抗细菌的筛选鉴定及其防病效果

为寻找对杧果炭疽菌Colletotrichum gloeosporioides有效的生防菌株,从瓜叶白粉病病斑上分离得到104株细菌,通过平板对峙培养筛选出16株拮抗细菌,分别测定其在8种不同培养基中的抑菌活性,筛选出有较强抑菌作用的9A、26A和4N菌株进行室内、果园防病试验,并对具有较好防治作用的9A、26A菌株进行了鉴定。结果显示,拮抗菌9A、26A和4N分别在南瓜汁、红薯汁和马铃薯汁培养基上的抑菌活性最高,对杧果炭疽菌菌丝生长抑制率分别为88.83%、87.83%和85.87%;室内9A、26A和4N菌株菌液处理离体果实,24 h后接种炭疽菌分生孢子液,对杧果炭疽病的防治效果均达100%,与咪鲜胺对照组相同;在果园9A和26A的防病效果分别为98.4%和90.5%,显著高于对照组的防效78.8%,而4N的防效只有58.2%。根据形态、生理生化特征及16S rDNA 序列分析结果,将菌株9A和26A鉴定为枯草芽胞杆菌Bacillus subtilis。研究表明,菌株9A和26A具有较好的生防利用价值。     

Antifungal activity of Datura stramonium, Calotropis gigantea and Azadirachta indica against Fusarium mangiferae and floral malformation in mango

Floral malformation caused by Fusarium mangiferae is a serious threat to mango cultivation in various countries. Different long-term measures suggested to control it were found to be unsuccessful. Present studies clearly showed strong antifungal activity of a concoction brewed from Datura stramonium, Calotropis gigantea, Azadirachta indica (neem) and cow manure (T₁) followed by methanol-water (70/30 v/v) extracts of Datura stramonium, Calotropis gigantea and Azadirachta indica (T₂) against Fusarium mangiferae. Optimal control of floral malformation was found in trees sprayed with T₁ followed by T₂ at bud break stage and again at fruit set stage when compared with the control. All the malformed buds or panicles completely dried two days after foliar spray with T₁ or T₂. In the trees treated with T₁ at fruit set stage, flower abscission was observed from the fourth day after spraying and all flowers dropped by the ninth day without requiring any manual de-blossoming, whereas in the control, the malformed panicles remained green and competed with the growing fruits for plant nutrients. In vitro culture of fresh malformed tissues in MS media along with T₁ or T₂ showed no growth of any fungus in the media. However, in vitro culture of the completely dry malformed tissues in MS media after foliar treatment with T₁ or T₂ revealed growth of F. mangiferae on the twenty fifth day indicating that the concoction-brewed compost (T₁) or methanol-water (70/30 v/v) extracts (T₂) could not completely eliminate the pathogen but helped in controlling malformation by suppressing the activity of F. mangiferae. Mango trees sprayed with T₁ and T₂ revealed significant differences in percent fruit set and retention when compared with the control. This could be due to observed higher levels of nitrogen, phosphorus, potassium, calcium, magnesium, copper, zinc, iron and manganese in T_1, followed by T₂ when compared with T₃ (control). Among the different fruit quality parameters analysed, the total flavonoids were found to be significantly higher in T₁ and T₂ when compared with T_3. The study proved that the concoction-brewed compost (T₁) is effective, inexpensive, easy to prepare and constitutes a sustainable and eco-friendly approach to control floral malformation in mango when it is sprayed at bud break stage and again at fruit set stage. In this present study, exogenous treatment of emerging buds with (T_c) further proved that with increase in the number of malformed panicles/tree the number of buds developing into healthy panicles/tree decrease.     

基于Histone H3、EF-1α和β-tubulin基因部分序列的芒果畸形病菌鉴定与系统发育研究

<正>芒果畸形病是芒果生产中重要的病害之一,主要表现为花畸形和芽畸形,受害果园常因畸形花絮无法挂果而造成减产,我国攀西地区的部分果园株发病率高达100%,给当地的芒果产业带来严重经济损失。该病自1891年首次在印度发现后,陆续在世界芒果产区发生危害~([1])。引起芒果畸形病的病原菌有Fusarium mangiferae、F.mexicanum、     

Epidemiological aspects of mango malformation disease caused by Fusarium mangiferae and source of infection in seedlings cultivated in orchards in Egypt

Mango malformation, caused by the fungus Fusarium mangiferae , is one of the major diseases of this crop occurring worldwide. This study was conducted to investigate aspects of the epidemiology, survival and spread of the pathogen in general and specifically in seedlings, the majority of which are cultivated in infected orchards in Egypt. Survival of conidia of a representative isolate (506/2) declined very rapidly in soil under summer conditions (1·6 weeks for 50% population decline), but significantly less in controlled and winter conditions (17·9 and 15·0 weeks, respectively, for 50% population decline). Likewise, inoculum survival in naturally infected panicles on the soil surface declined faster than in those buried at 30-cm depths. Natural infections were evaluated on fruits and seeds in a heavily infected and a healthy orchard. In infected trees, the skins of all sampled fruits within a 2-m radius of infected panicles were infected, but the pathogen was not detected in the seeds, seed coats or flesh. The pathogen was not detected in any parts of fruits from a healthy orchard. Vegetatively malformed mango seedlings, growing under infected trees bearing infected panicles, were sampled in two locations in Egypt to determine whether infection in seedlings was systemic (evenly distributed within plant tissue) or whether the pathogen originated from malformed panicles. According to PCR-specific primer amplification, the pathogen was detected in 97% of seedling apical meristems, declining gradually to 5% colonization in roots. It was concluded that inoculum of the pathogen originates from infected panicles and affects seedlings from the meristem, with infections descending to lower stem sections and roots. Minor infections of roots may occur from inoculum originating from infected panicles, but the pathogen is not seedborne.     

芒果畸形病的研究概况

芒果畸形病是对芒果生产最具破坏性的病害之一。目前国际上虽对其进行了大量的研究,但对其病原、发病因子、侵染循环等仍未有定论,且尚未找到有效的防治方法。笔者结合国外相关研究资料,介绍了对芒果畸形病的研究概况,以期引起芒果生产者的重视,并供研究者参考。     

海南省芒果可可球二孢对多菌灵的敏感性及菌株适合度研究

针对中国海南地区芒果蒂腐病致病菌可可球二孢对多菌灵的抗性水平及菌株的适合度进行了研究。采用区分剂量法,测定了2016年从海南省芒果园采集、分离的90株可可球二孢对多菌灵的敏感性,并对抗性及敏感菌株在菌丝生长、致病力、渗透压及相对渗率等方面进行了比较。结果表明:海南地区芒果可可球二孢对多菌灵的抗性频率为65.56%,且以高抗菌株为主（8个中抗菌株,51个高抗菌株）;该病菌对芒果危害甚大,其中具强致病力的菌株达65株,占72.22%。高抗菌株的菌丝生长优于敏感菌株,存在极显著差异（P0.01）;抗性菌株的致病力与敏感菌株无显著差异;敏感菌株的相对渗率高于抗性菌株,表明敏感菌株细胞膜的透性较高,胞内电解质渗出较多。研究表明,海南地区芒果可可球二孢对多菌灵的抗性水平较高,且抗性菌株适合度高于敏感菌株,易形成优势群体。     

植物之间互作效应及其生理机制

在分析不同植物互作效应的基础上,就互作效应在农林复合系统中对植物体内养分、土壤养分有效性及植物生物学产量等的影响进行了概述,(1)互作促进了植物根系生长,使植物根系表现出较强的竞争作用,也有利于根系间的养分竞争;(2)植物之间的他感作用普遍存在于自然生态系统及栽培生态系统中,在植物资源配置时应充分利用这种相生相克作用;(3)互作促使植物体内的养分转移,改善体内的养分状况,达到植物之间养分互补;(4)互作可以有效地提高土壤肥力,改善土壤的养分状况和根际养分吸收环境,维持植物生产力;(5)互作能更有效地利用光、热、水、土和养分等资源,并减轻病虫危害,表现出明显的产量优势。在豆科与非豆科植物互作中,豆科植物的生物固氮作用为其互作植物提供了氮素营养保证,这种形式互作的产量优势通常在缺氮情况下表现更为明显。     

Development of a real-time fluorescence loop-mediated isothermal amplification assay for rapid and quantitative detection of Fusarium mangiferae associated with mango malformation

Fusarium mangiferae is a major causal agent of mango malformation disease (MMD) worldwide. Rapid and accurate detection of the causal pathogen is the cornerstone of integrated disease management. In this paper, a real-time fluorescence loop-mediated isothermal amplification assay (RealAmp) was developed for quantitative detection of F. mangiferae in China. The LAMP primer set was designed based on a RAPD marker sequence and positive products were amplified only from F. mangiferae isolates, but not from any other species tested, showing a high specificity of the primer sets. The detection limit was approximately 2.26 × 10⁻⁴ ng/μl plasmid DNA when mixed with extracted mango DNA. Quantification of the pathogen DNA of MMD in naturally collected samples was no significant difference compared to classic real-time PCR Additionally, RealAmp assay was visual with an improved closed-tube visual detection system making the assay more convenient in diagnostics.     

MEAM1和MED两个烟粉虱隐种取食对甘蓝转录组影响的差异

为绿色防控烟粉虱Bemisia tabaci提供新策略,采用转录组分析MEAM1和MED两个烟粉虱隐种取食后甘蓝差异基因表达情况,并选取差异表达基因最多的甘蓝苯丙烷类通路上PAL2、C4H、4CL1和CHI四个基因进行实时荧光定量PCR测定。结果显示,与对照相比,MEAM1和MED烟粉虱隐种取食后甘蓝差异表达基因数分别为693个和1 030个。GO功能注释和KEGG富集分析显示,差异表达基因主要集中在苯丙烷类生物合成、萜类挥发物合成、芥子油苷合成、类黄酮生物合成和植物激素信号传导途径等与甘蓝抗虫物质合成相关的通路上。虽然MEAM1与MED两个烟粉虱隐种均能显著激活植物激素信号传导途径和苯丙烷类合成通路调控的酚类物质合成途径,但MED烟粉虱隐种与甘蓝互作的差异表达基因数高于MEAM1烟粉虱隐种。MEAM1烟粉虱隐种取食甘蓝12 h后,甘蓝苯丙烷通路上游PAL2、C4H和4CL1三个基因均显著上调,而MED烟粉虱隐种取食后,甘蓝苯丙烷通路上PAL2、C4H、4CL1和CHI四个基因均变化不显著,这4个差异基因的表达模式与测序结果一致,表明测序结果的可信度高。     

不同色型异色瓢虫转录组差异表达基因分析

为探究不同色型异色瓢虫Harmonia axyridis之间产生生理学差异的机制,通过Illumina HiSeq测序平台对黄底多窗型、黑底两窗型和黑底四窗型3种不同色型异色瓢虫雌雄成虫的18个转录组进行高通量测序,比较不同色型间的差异表达基因,并结合GO和KEGG数据库对差异表达基因进行注释分析。结果表明：通过对差异表达基因进行定量比较发现,与黄底多窗型相比,2种黑底型异色瓢虫雌雄成虫的下调基因明显更多;GO功能分类结果显示,不同色型的异色瓢虫雄成虫和雌成虫差异表达基因所属分类基本相似,并未见显著富集现象,且主要属于细胞过程、单组织活动和细胞等类别;通过KEGG数据库比对分析发现不同色型异色瓢虫中的差异表达基因功能主要与环境适应和能量代谢通路相关。其中,与氧化磷酸化过程相关的基因在2种黑底型异色瓢虫中的表达量显著低于黄底多窗型异色瓢虫,这种差异在雌成虫中更为显著。