小麦禾谷孢囊线虫寄生范围的研究

经测试表明,禾谷孢囊线虫(Heterodera avenae)对长江中游地区栽种的小麦、裸大麦、米大麦、家燕麦、野燕麦、黑麦草、鹅冠草、苇状羊茅、球茎草芦和鸭茅均能侵染,这些植物是该线虫的良好寄主,但感染率差异不显著。该线虫能侵染玉米,但很难完成生活史,不侵染供试的红三叶草和紫苜蓿2种非禾本科牧草。在不同的寄主根内,线虫发育速度有差异,单位重量根内虫口数亦有异,黑麦草内最多,鲜根有线虫4.45条/g,鸭茅最少为1.26条/g。     

葡萄霜霉菌候选效应子RXLR5信号肽的鉴定

利用Getorf、SignalP 3.0、BLASTP等生物信息学软件和PERL语言从葡萄霜霉菌基因组中预测到一条编码RXLR-EER结构域的效应蛋白候选基因,将该基因编码的蛋白命名为RXLR5。将RXLR5信号肽SP5编码序列连接到pSUC2T7M13ORI载体并转化到酵母蔗糖酶缺陷菌株YTK12后,重组菌株能成功分泌蔗糖酶,促使棉籽糖分解成单糖,因此,能在YPRAA培养基上正常生长;同时生成的单糖能与TTC反应产生红色不溶于水的氯化三苯基四氮唑。由此推测,SP5具有信号肽活性,可能在RXLR5从葡萄霜霉菌细胞内泌到胞外的过程中起重要作用。     

Sibling species of cercospora associated with gray leaf spot of maize

ABSTRACT Monoconidial isolates of the fungus causing gray leaf spot of maize were obtained from diseased leaves collected throughout the United States and analyzed for genetic variability at 111 amplified fragment length polymorphism (AFLP) loci. Cluster analysis revealed two very distinct groups of Cercospora zeae-maydis isolates. Both groups were found to be relatively uniform internally with an average genetic similarity among isolates of approximately 93 and 94%, respectively. The groups were separated from each other by a genetic distance of approximately 80%, a distance greater than that separating each group from the sorghum pathogen, C. sorghi (67 to 70%). Characteristics and dimensions of conidia and conid-iophores produced on infected plants or nutrient media were unreliable criteria for taxonomic differentiation of isolates composing the two groups of C. zeae-maydis. Nucleotide sequences of 5.8S ribosomal DNA (rDNA) and the internal transcribed spacer (ITS) regions were identical within each group but different between the two groups and different from C. sorghi. Restriction fragment length polymorphisms generated by digestion of the 5.8S rDNA and ITS regions with TaqI readily distinguished each group and C. sorghi. Isolates in one group were generally distributed throughout maize-producing regions of the United States; isolates in the other group were localized in the eastern third of the country. Both types were present in the same fields at some locations. The genetic distance based on AFLP profiles and different ITS nucleotide sequences between the two morphologically indistinguishable groups indicate that they are sibling species. Although it is unlikely that breeding for resistance to gray leaf spot will be confounded by local or regional variation in the pathogen, a vigilant approach is warranted, because two pathogenic species exist with unknown abilities to evolve new pathotypes.     

莴苣花叶病毒病的研究Ⅰ。病原鉴定

 由山东济南和泰安两市郊区大面积受害的莴苣(Lactuca sativa L.var.asparagina L.)上分离到一株病毒。莴苣上症状为系统花叶,畸型和褐色斑点。人工接种,在昆诺阿藜和苋色藜上产生局部枯斑和系统症状,千日红上呈不规则斑块,不侵染普通烟、心叶烟、曼陀罗、豇豆、菜豆和黄瓜。传毒试验证明经汁液和蚜虫传播,种子带毒。病毒稀释限点5×10^-1~5×10^-2;失活温度55~60℃;体外保毒期(22~23℃)24小时,经有机溶剂澄清,聚乙二醇沉淀和差速离心可部分提纯。病毒粒子线状,长约750毫微米;病组织超薄切片可见风轮状内含体。试管沉淀法初步测定与马铃薯Y病毒血清呈阳性反应。     

Molecular cloning and functional analysis of duck Toll-like receptor 5

Toll-like receptor 5 (TLR5) is responsible for the recognition of bacterial flagellin in vertebrates. In this study, we cloned the single-exon TLR5 gene of the Maya breed of Common Shelduck (Tadorna tadorna). The TLR5 open reading frame is 2580 bp in length and encodes an 859-amino acid protein. The putative amino acid sequence of duck TLR5 consisted of a signal peptide sequence, 11 leucine-rich repeat domains, a leucine-rich repeat C-terminal domain, a transmembrane domain, and an intracellular Toll-interleukin-1 receptor domain. The duck TLR5 gene was highly expressed in the lung, bone marrow, spleen, and liver; moderately expressed in kidney, small intestine, large intestine, and brain. A plasmid expressing duck TLR5 was constructed and transfected into HEK293T cells, and expression was confirmed by indirect immunofluorescence assay. HEK293T cells transfected with duck TLR5- and NF-κB-luciferase-containing plasmids significantly responded to flagellin from Salmonella typhimurium, indicating that it is a functional TLR5 homolog.     

基于深度学习的病虫害智能化识别系统

我国农作物种植覆盖面广、分散度高,病虫害发生种类多、区域性发生规律复杂,传统的人工鉴定技术从效率、能力与精度方面均难以满足新形势下重大病虫测报要求。针对这一实践需求,以测报灯下害虫图像数据库(约18万张)、田间病虫害图像数据库(约32万张)为基础,构建了基于深度学习方法的病虫害种类特征自动学习、特征融合、识别和位置回归计算框架,并研发了移动式病虫害智能化感知设备和自动识别系统。通过近2年的精确度和实操运行效率检验,该系统在自然状态下对16种灯下常见害虫的识别率为66%～90%,对38种田间常见病虫害(症状)的识别率为50%～90%。随基础数据库的不断丰富、神经网络深层特征提取的不断完善,该系统有望进一步提高识别准确率,从而真正实现田间病虫害识别自动化、智能化和高效率。     

乌鲁木齐周围地区栅藻属植物研究

本文首镒报道新疆乌鲁木齐，昌吉部分地区的水库，鱼塘，公园，水渠等１４处２０个点的栅藻属７种４变种１变型，其中有２种４变种１变型是新疆维吾尔自治区新记录。     

水稻雄性不育突变体012S-3的遗传分析和基因定位

雄性不育是水稻杂种优势利用的重要资源,对雄性不育现象的研究具有重要理论意义和实践价值。本研究以自然突变的水稻雄性不育突变体012S-3为试验材料,对其表型特征和花粉育性等进行调查,并构建遗传群体,利用分子标记对目的基因进行初步定位,然后应用基因组重测序技术对其进行精细定位。结果表明,012S-3是一个典型的无花粉普通型雄性不育材料,其不育性状受1对隐性核基因控制。初步定位分析目的基因与SSR标记RM6081存在连锁关系,其遗传距离约为34.4 c M;进一步的精细定位分析,找到3个候选基因:LOC_Os07g35880、LOC_Os07g35920和LOC_Os07g35940,其中LOC_Os07g35880和LOC_Os07g35940编码β-淀粉酶,属于水稻中新发现的花粉致死基因。该不育基因的成功定位为其进一步的分离克隆及其在水稻分子设计育种中的应用奠定了基础。