白花泡桐种源的遗传多样性和遗传分化研究

利用ISSR技术对白花泡桐38个种源的遗传多样性和遗传分化进行分析。结果显示：（1）从100个ISSR引物中筛选出9个能扩增出清晰带型并具多态性的引物,共扩增出95个条带,其中88条具多态性,多态位点比率为92.63%。（2）在物种水平上,有效等位基因数（N_e）、Nei’s基因多样性指数（H）、Shannon’s信息指数（I）的平均值分别为1.391 0、0.242 4、0.376 5;种源的多态位点比率在32.63%（江西抚州）~56.84%（广西梧州和江西九江）之间,平均为47.16%;基因流（N_m）为0.912 7,种源间遗传分化系数（G_st）为0.353 9,反映出种源间遗传变异占总遗传变异的35.39%,且遗传变异主要来源于种源内的个体间。（3）遗传一致度在0.39~0.82之间,反映出白花泡桐的遗传基础较宽。UPGMA法聚类分析将38个种源分为3组,主坐标分析(PCoA)将其大致分为4组,两种聚类方法的结果有一定的差异,本文做了相关讨论。研究还表明种源间的遗传距离与地理距离相关不显著。     

Post-establishment assessment of host plant specificity of Arytainilla spartiophila (Hemiptera: Psyllidae), an adventive biological control agent of Scotch broom,Cytisus scoparius

Scotch broom, Cytisus scoparius (Fabaceae), is a shrub native to Europe that is invasive in the USA, New Zealand and Australia. The psyllid Arytainilla spartiophila has been purposely introduced to Australia and New Zealand as a biological control agent of C. scoparius, but is an accidental introduction to California. Lupines (Lupinus spp.) are the closest native taxon to Cytisus in North America, and are therefore considered to be at the highest risk for non-target damage. However, because no lupines are native to Australia or New Zealand, only one imported forage species was evaluated during prior host specificity testing. We conducted a laboratory nymphal transfer experiment, a field choice experiment and a field survey to assess risk to three lupine species (Lupinus albifrons, Lupinus bicolor and Lupinus formosus). In the laboratory, 20% of third-instar nymphs were able to develop to adulthood on L. formosus but not on the other lupine species, while 40% completed development on C. scoparius. In the field experiment, potted lupine and C. scoparius plants were placed beside large infested C. scoparius plants; oviposition occurred on all the potted C. scoparius plants, but on none of the lupines. In the field survey, no A. spartiophila eggs or nymphs were found on naturally occurring lupines growing adjacent to infested C. scoparius. The results indicate that A. spartiophila is not likely to damage or reproduce on lupines in the field. This study provides an example of how field studies can help clarify the host specificity of biological control agents.     

南疆红枣产区枣疯病发生现状及主导因子分析

【目的】枣疯病是枣树生产中的毁灭性病害。研究南疆枣疯病发生危害现状及主导因子,可为该病的预测预报和防治提供依据。【方法】连续4年对新疆阿克苏地区、喀什地区枣疯病发生情况进行调查及分子检测,并分析了种植模式与管理水平、枣树品种与种植年限、传播方式等因素对枣疯病发生的影响。【结果】目前,新疆南疆红枣产区枣疯病尚属零星、团簇状分布。嫁接育苗是多数枣产区病园内苗期和幼树发病以及病害从病区传入无病区的主要原因,酸枣实生苗也是不可忽视的病害侵染来源。不同枣树品种对枣疯病的田间抗性表现出一定的差异。利用巢氏PCR检测及TaqMan探针实时荧光定量PCR检测技术对田间样品的检测结果显示,病园内存在着比例不等的无症带菌植株。【结论】无症带菌苗的人为传播是导致南疆地区枣疯病发生和流行的主导因素。     

Production of lytic enzymes and siderophores, and inhibition of germination of basidiospores of Moniliophthora (ex Crinipellis) perniciosa by phylloplane actinomycetes

Streptomyces albovinaceus, Streptomyces caviscabies, Streptomyces griseus, Streptomyces setonii, and Streptomyces virginiae selected as antagonists of Moniliophthora (ex Crinipellis) perniciosa, the causal agent of cacao Witches’ broom, were examined in vitro to detect production of chitinases, β-1,3-glucanases, and cellulases. All the species produced chitinases, but not β-1,3-glucanases or cellulases, when grown on a liquid mineral medium containing glucose, colloidal chitin, or cell walls of M. perniciosa as a carbon source. There were no quantitative differences among species in the production of chitinase, however, the germination inhibition of basidiospores of M. perniciosa was higher when they were cultivated using glucose as a carbon source, followed by colloidal chitin and cell walls. All the species also produced hydroxymate type siderophores in similar quantities, and the quantity of siderophores did not correlate with the inhibition of basidiospore germination. The germination inhibition was more pronounced when S. albovinaceus, S. griseus, and S. virginiae were cultivated on iron-deficient medium, suggesting involvement of siderophores in the antagonism by these species of actinomycetes.     

空桐树的化学成分研究(英文)

从空桐树(Paulownia kawakamii)首次提取分离出7个化合物,经波谱分析和化学反应,分别鉴定为α-lapachone(1)、9-hydroxy-α-lapachone(2)、黄钟花醌(3)、芝麻素(4)、泡桐素(5)、谷甾醇棕榈酸脂(6)和β-谷甾醇(7).     

毛泡桐与白花泡桐正反交F1无性系自然接干性状的遗传变异

利用田间实验和统计分析方法,研究了毛泡桐[Paulownia tomentosa（Thunb．）Steud．]与白花泡桐[P.fortunei（Seem．）Hemsl．]正反交F1无性系自然接干性状的遗传变异。结果表明,供试的11个F1无性系的22个自然接干性状具有广泛而明显的遗传变异和变异差异,其中接干高、全干高、接干材积、全干材积、接干材秽全干材积、通直度和丛枝病等级是变异最大的7个自然接干性状（CV〉30）;在6个正交F1无性系间和5个反交F1无性系间,绝大多数自然接干性状的差异达极显著水平;在毛泡桐与白花泡桐正交F1无性系和反交F1无性系间,22个自然接干性状均存在极显著差异。     

陕西省枣疯病的潜在风险分析及管理对策

[目的]枣疯病是我国枣树的一种毁灭性病害。近年来,该病害在陕西枣区发病面积日益扩大,造成枣树成片死亡,对陕西的红枣产业构成严重威胁。本文旨在明确枣疯病在陕西省的风险等级,为枣疯病的管控提供依据。[方法]采用有害生物风险分析程序和方法,从枣疯病发生现状、潜在危害性、寄主的经济重要性、定殖扩散的可能性以及风险管理的难度等5个方面,对枣疯病在陕西省的风险性进行了定性和定量综合评估。[结果]枣疯病在陕西全部枣区适生,在陕西省的风险综合评价值R=2.84,危险等级为Ⅰ级。[结论]枣疯病在陕西属于特别危险有害生物,对陕西红枣产业有很高的风险。根据其危险等级,提出应清除病原和严格检疫、加强枣园管理和防治媒介昆虫等管理对策。     

桐-药复合经营模式下泡桐丛枝菌根真菌群落结构特征

采用Illumina MiSeq高通量测序技术,研究江西鄱阳湖周边平原岗地的泡桐纯林及桐-药复合经营模式(泡桐-玉竹、泡桐-麦冬和泡桐-射干)下泡桐丛枝菌根真菌(arbuscular mycorrhizae fungi, AMF)群落结构特征。研究发现,泡桐AMF群落主要由球囊霉科、巨孢囊霉科、无梗囊霉科和多孢囊霉科组成,其中球囊霉科真菌占绝对优势,但不同科的相对丰度在不同经营模式下仍存在差异。与泡桐纯林相比,桐-药复合经营模式会降低泡桐菌根侵染率及AMF群落多样性。只有泡桐-射干经营模式中的泡桐含有多孢囊霉科真菌,且相对多度占2.73%。研究结果表明桐-药复合经营模式下中药材种类的差异会不同程度地改变泡桐AMF的群落结构。这为进一步研究桐-药复合经营模式下泡桐AMF的生态功能和资源利用提供了科学依据。     

多重PCR法区分枣园两种菱纹叶蝉及检测其体内枣疯病植原体

【目的】目前发现,北京枣园中的凹缘菱纹叶蝉Hishimonus sellatus(Uhler)和片突菱纹叶蝉Hishimonus lamellatus Cai混同发生。已知凹缘菱纹叶蝉可以传播枣疯病,而片突菱纹叶蝉是否携带枣疯病植原体尚待证明。正确鉴别区分枣园中菱纹叶蝉的种类并测定其体内感染枣疯病植原体情况有助于阐明田间枣疯病的流行规律,从而提出有效的预防枣疯病及其媒介昆虫措施显得十分重要。传统形态学鉴定两种菱纹叶蝉种类的方法局限于雄性成虫外生殖器,本研究目的在于建立一种快速的分子生物学方法,在区分枣园中两种枣菱纹叶蝉的同时,可检测虫体内的枣疯病植原体。【方法】以凹缘菱纹叶蝉和片突菱纹叶蝉的COI基因以及枣疯病植原体的16S r DNA为扩增目标,分别设计引物,建立一种包含3对引物的多重PCR体系。测试该多重PCR体系对叶蝉总DNA的灵敏度、准确性,以及当两种叶蝉DNA同时存在时的辨别能力和对枣疯病植原体16S r DNA的灵敏度。【结果】该多重PCR可以准确区分凹缘菱纹叶蝉和片突菱纹叶蝉,并对虫体内枣疯病植原体实现检测,其对昆虫总DNA的灵敏度达到0.012 ng,对枣疯病植原体16S r DNA模板的灵敏度达到900拷贝。【结论】该方法极大方便了对枣菱纹叶蝉的田间种群发生动态及虫体中枣疯病植原体感染的监测。