Prepenetration stages in infection of clematis by Phoma clematidina     

P. van de Graaf †  M. E. Joseph  J. M. Chartier-Hollis  T. M. O'Neill 《Plant pathology》2002,51(3):331-337

A detailed study of conidial germination, germ-tube growth and the formation of infection structures in Phoma clematidina , the causal agent of clematis wilt, is described for two clematis varieties differing in disease resistance. On both the resistant and susceptible varieties, the fungus entered leaves and stems by direct penetration of the cuticle, often, but not always, following the formation of infection structures. More germ tubes per conidium were formed on the susceptible host, but these germ tubes were on average shorter than on the resistant host. Although germ tubes regularly entered the plant via trichomes, stomata were not found to be sites of entry. Following penetration of the cuticle of resistant plants, germ-tube growth was sometimes restricted to the subcuticular region, and halo formation occurred at the sites where penetration was attempted. Subcuticular growth and halo formation were not observed on susceptible plants. These observations may partly explain the resistance of small-flowered clematis varieties to P. clematidina .  相似文献   

双孢蘑菇子实体原基形成的超微结构研究     

李荣春 《云南农业大学学报(自然科学版)》2001,16(4):277-279

 应用低温扫描电子显微镜（LTSEM）对双孢蘑菇子实体原基的超微结构特征进行了观察研究。研究表明,双孢蘑菇子实体原基的形成经历了起源,发展和分化的不同阶段,在不同阶段时期其超微结构特征具有较大的差异。低温扫描电子显微镜和本文介绍的制样技术是适合于观察子实体原基这类较幼嫩组织的超微形态结构特征的。  相似文献