Effect of mycorrhizal infection on the early growth of protocorm in Habenaria radiata 'Aoba' and 'Gyokuryuka'.

摘要

The stimulatory effects of mycorrhizal infection on the early growth of H. radiata cultivars Aoba and Gyokuryuka protocorms, grown from seeds inoculated with Rhizoctonia repens isolate 931202A, were investigated. The protocorms of Gyokuryuka (2n = 64) enlarged faster than those of Aoba (2n = 32). It is suggested that the difference was due to higher susceptibility of Gyokuryuka protocorms to mycorrhizal infection, earlier differentiation and functioning of conductive tissue in Gyokuryuka protocorms, and a higher degree of invasion of Gyokuryuka protocorms by the fungus. It is concluded that the infectivity of the mycorrhizal fungus and the susceptibility of the H. radiata cultivar are decisive factors affecting early seedling growth.