Suppression of Rhizoctonia root-rot of tomato by Glomus mossae BEG12 and Pseudomonas fluorescens A6RI is associated with their effect on the pathogen growth and on the root morphogenesis   总被引：1，自引：0，他引：1  

Graziella Berta  Simonetta Sampo  Elisa Gamalero  Nadia Massa  Philippe Lemanceau 《European journal of plant pathology / European Foundation for Plant Pathology》2005,111(3):279-288

Rhizoctonia solani root-rot is a major soilborne disease causing growth and yield depression. The ability of Glomus mosseae BEG12 and Pseudomonas fluorescens A6RI to suppress this soilborne disease in tomato was assessed by comparing the shoot and root growth of plants infested with R. solani 1556 when protected or not by these beneficial strains. The epiphytic and parasitic growth of the pathogenic R. solani 1556 was compared in the presence and absence of the biocontrol agents by microscopical observations allowing the quantification of roots with hyphae appressed to epidermal cells (epiphytic growth) and of roots with intraradical infection (parasitic growth). The root architecture of the tomato plants under the different experimental conditions was further characterized by measuring total root length, mean root diameter, number of root tips and by calculating degree of root branching. G. mosseae BEG12 and P. fluorescens A6RI fully overcame the growth depression caused by R. solani 1556. This disease suppression was associated with a significant decrease of the epiphytic and parasitic growth of the pathogen together with an increase of root length and of the number of root tips of inoculated tomato plants. The combined effects of G. mosseae BEG12 and P. fluorescens A6RI on pathogen growth and on root morphogenesis are suggested to be involved in the efficient disease suppression.  相似文献   

Ovine Lentivirus is Aetiologically Associated with Chronic Respiratory Disease of Sheep on the Laikipia Plateau in Kenya     

Rwambo  P.M.  Brodie  S.J.  DeMartini  J.C. 《Tropical animal health and production》2001,33(6):471-487

A study was undertaken to investigate the occurrence of ovine lentivirus (OvLV) infection in sheep with chronic respiratory disease on the Laikipia Plateau, Kenya. All seven Merino crossbred sheep with chronic dyspnoea and emaciation examined for gross and microscopic lesions had lymphoid interstitial pneumonia (LIP), and one also had pulmonary abscesses. Two of the sheep with LIP also had lesions of ovine pulmonary carcinoma (OPC, jaagsiekte). Using in situ hybridization, OvLV DNA localized to a high proportion of pulmonary macrophages in lungs with lesions of LIP. Lung tissue samples from six of these sheep were positive for a syncytium-inducing virus in cultures of lamb testis cells. Thin-section electron microscopy of infected cells showed virions with morphogenesis typical of lentiviruses. In a western blotting assay, monoclonal antibodies to the OvLV capsid (CA, p27) and matrix (MA, p15) proteins of a North American OvLV isolate reacted with similar-sized bands of the virus, and serum from six of the sheep were reactive with CA from the Kenyan viral isolate. Using an OvLV agar gel immunodiffusion (AGID) test, all seven sheep were positive for serum antiviral antibody, as were 29% of 63 clinically normal sheep from Laikipia District. However, when sera from the healthy sheep were tested in a western blot assay, only 52% had IgG reactive to the OvLV CA, indicating a high rate of false negative reactions with the AGID test. Serum samples from 87 Red Maasai or Dorper crossbred sheep from two farms in other parts of Kenya were OvLV seronegative by both the AGID test and the western blot assay. These results document the first identification of OvLV as a cause of chronic respiratory disease in sheep in Kenya and show a high rate of infection in sheep flocks, with a high prevalence of chronic respiratory disease.  相似文献   

Effects of in utero retinoic acid exposure on mouse pelage hair follicle development     

García-Fernández RA  Pérez-Martínez C  Escudero-Diez A  García-Iglesias MJ 《Veterinary dermatology》2002,13(3):157-163

Abstract We investigated in vivo the histological and immunohistochemical responses of mouse hair pelage follicle morphogenesis to prenatal exposure to a potentially nonteratogenic dose of all- trans -retinoic acid (RA), as a basis studying the preventive effect of RA on adult mouse skin carcinogenesis. In pregnant mice, a single oral dose of RA at 30 mg kg⁻¹ body weight given on day 11.5 of gestation caused no RA-induced changes in the morphology or temporal expression patterns of keratins during pelage hair follicle morphogenesis. The only differential effect of RA was a statistically significant increase in the number of BrdU-positive nuclei in hair bulbs from RA exposed fetuses compared with nonexposed mice. The absence of adverse RA effects suggests that this experimental design may represent a valuable protocol for use in studies on the in vivo effects of this retinoid on different skin diseases.  相似文献   

斑马鱼孵化期组织形态学研究   总被引：3，自引：1，他引：2  

马瑛 《广西农业科学》2010,41(9):981-983

为进一步了解斑马鱼孵化阶段的形态结构变化,采用活体观察与组织切片染色相结合的方法,对斑马鱼孵化期胚胎进行形态组织学观察。结果表明,斑马鱼运动器官＂鳍芽＂的伸长标志着胚胎孵化期的开始,此时可以清楚观察到胚体形态结构,如卵黄、头部、嗅基板、运动纤毛等;至胸鳍形成期,胚胎已经基本孵出卵膜,其内部器官形态发生已经基本形成,摄食器官口和运动器官、循环系统、感觉及其神经系统均进一步完善,为孵出后幼鱼的独立生存做好准备。  相似文献   

“红肉病”文蛤中发现的一种球形病毒的形态发生与细胞病理学   总被引：12，自引：1，他引：12  

任素莲 《水产学报》2002,26(3):265-269

在患“红肉病”文蛤的消化盲囊上皮细胞中发现了一种球形病毒及其发生基质。病毒粒子呈球形，无囊膜，直径约50－80nm，在细胞质内形成多泡状的包涵体并进行病毒粒子的装配。受感染的细胞具有明显的病理变化，主要表现为核固缩或肿胀并出现核空泡，内质网膨胀、大部分转化泡状，线粒体溶解或固缩，溶酶体数量增多等。  相似文献   

Morphogenesis, Anatomical Observation and Primary Genetic Analysis of a Multi-glume Floral Organ Mutant in Rice     

PAN Cun-hong LI Ai-hong Wu Ru ZHANG Ya-fang TANG Wen Wu Chang-yin ZHANG Qi-fa PAN Xue-biao 《水稻科学》2006,13(4):227-233

The floral development is one of the pivotal characteristics of the transition from vegetative to reproductive phase in plant, while the generated seeds are the important source of propagation and population dispersal. Furthermore, it serves as the foundation of grain yield and quality in crop. Therefore, the floral development and its regulation becomes current research hotspot in plant molecular biology. Previously, some genes controlling flower development have been cloned in Snapdragon and…  相似文献   

几种中国兰种子试管培养根状茎发生的研究   总被引：18，自引：0，他引：18  

陈进勇  程金水 《北京林业大学学报》1998,20(1):32-35

对蕙兰和墨兰的种子进行解剖学观察,可以看到种皮由一层透明的细胞组成,种胚为发育不完全的球形胚,胚内不含淀粉,仅含脂类作为储存营养物质．试管培养条件下,球形胚顶端细胞分裂,胚体积增大,胀破种皮,形成类原球茎．其顶端分生组织细胞继续分裂,形成根状茎．在激素诱导下,根状茎的表皮和皮层细胞可分裂形成侧生分生组织．然后顶生和侧生分生组织分化出叶原基,表皮和皮层细胞分化出不定根．在种子萌发成苗的过程中,脂类逐渐消失,蛋白质在分生组织细胞中含量较多,淀粉粒多分布在薄壁细胞中,与形态发生有密切关系．  相似文献   

苏博美利奴羊胎儿皮肤毛囊结构及形态发育研究   总被引：3，自引：1，他引：3  

阿布来提·苏来曼  田月珍  许琴  何军敏  赵冰茹  徐新明  付雪峰  热娜古丽·艾尼瓦尔江  黄锡霞  田可川 《中国农业科学》2017,50(16):3226-3235

【目的】研究苏博美利奴羊毛囊的组织结构与形态发育过程,为解析细毛羊毛囊发育的分子调控机制奠定组织学基础。【方法】采用石蜡切片技术分析胎龄为第65、85、105和135天的苏博美利奴羊胎儿头部、颈侧、颈上缘、鬐甲、背部、体侧、肩甲、腹部、荐部及股部等10个不同部位皮肤的组织学特性。【结果】苏博美利奴羊毛囊结构同其它动物一样,由毛球、连接组织鞘、外根鞘、内根鞘和毛干等几部分组成。在胎龄65d时初级毛囊(primary follicles, PF)已经发生形成毛芽,毛芽延长,继续向真皮层深入,形成柱状结构,通过由大量真皮细胞在末端聚集,形成帽子结构,各部位表皮均形成完整的结构。胎龄85d时毛囊上部形成一个膨大部,在毛乳头上方形成锥形结构,毛球基本形成,毛乳头长度明显大于宽度;在初级毛囊基底部可见次级毛囊（secondary follicles ,SF）的囊泡结构,并形成皮脂腺原始细胞。在胎龄105d时次级毛囊大量形成,伴随着初级毛囊毛芽伸长,次级毛囊毛芽向真皮层深入,毛乳头直径逐渐增大,皮脂腺开始形成;原始次级毛囊颈部隆突部开始再分化出再分化次级毛囊(secondary-derived follicles ,SD),并可见汗腺,毛管发育完整;已形成完整的毛囊群结构,主要为三元毛囊群,每个毛囊群由1—3个初级毛囊和围绕其周围的几个次级毛囊组成。胎龄135d时大量形成再分化次级毛囊,形成成熟的汗腺,大部分初级毛囊和部分次级毛囊发育成熟,毛囊形成角质化毛干并穿出体表。【结论】苏博美利奴羊胚胎皮肤初级毛囊约50—55d开始形成;胎龄65—75d是初级毛囊形成的重要时期;胎龄80—85d是次级毛囊形成期,此时期,初级毛囊大量形成;胎龄105—135d是次级毛囊大量再分化,再分化次级毛囊形成及发育的关键时期。为了解苏博美利奴羊毛囊的结构及毛囊从发生到发育成熟的形态变化过程,为相关领域研究提供参考依据。  相似文献   

几种中国兰种子试管培养愈伤组织发生的研究   总被引：8，自引：0，他引：8  

陈进勇  程金水 《北京林业大学学报》1998,20(4):76-79

中国兰种子细小,种皮细胞壁加厚,表面覆盖一层不透水不透气的膜状物质．种胚为发育不完全的球形胚,仅含脂类作为储存营养物质,自然条件下难以萌发．以蕙兰和墨兰的种子进行试管培养,种子萌发后用激素处理可诱导产生愈伤组织,愈伤组织产生于表皮和皮层细胞,由于细胞发育程度不一致,出现胚状体、不定芽、不定根、愈伤组织交织在一起的愈伤组织块,这是种子发育成苗的另一途径．由于愈伤组织可以切割继代培养,也可以进行快速繁殖,但愈伤组织材料以致密愈伤组织为好．  相似文献   

EMS诱变玉米自交系种质创新应用   总被引：1，自引：0，他引：1  

周文期  连晓荣  周玉乾  王兴荣  杨彦忠  刘忠祥  王晓娟  何海军  寇思荣 《玉米科学》2020,28(6):31-38

利用0.5 mg/L EMS诱变玉米自交系K22及B73花粉，构建2 206个株系不同遗传背景的玉米突变体库，从M₂和M₃后代筛选到包括株型、叶型、叶色、育性、抗逆、表皮形态建成等表型变异的一系列突变体。具有育种应用潜能的E16、E199和W594突变材料，可供用于选育矮秆、低穗位高、耐密植抗倒伏型新品种。对调控植物表皮形态建成的E88和sep-1（smooth epidermal pavement cell lobes-1）突变体进行表皮形态、发育模式鉴定及遗传学分析，构建了F_2：3分离群体。  相似文献