Resistance to yellow–leaf disease in phormium tenax forst. and the occurrence of delayed expression of symptoms

摘要

Abstract One cultivar and two seedling progenies from cultivars of Phormium tenax have been tested experimentally for resistance to transmission of yellow–leaf disease by Oliarus atkinsoni Myers. Results show that cultivar ‘SS‘ is resistant to but not immune from the disease, that second inbred generation (S2) seedling progeny of ‘301‘ is highly susceptible, and that first inbred generation (S1) progeny of ‘SS‘ is intermediate, that is, less resistant than ‘SS‘ but not as susceptible as ‘301‘ S2. Evidence of long delay in the expression of symptoms was obtained during the course of this experiment and from observations continued after the conclusion of formal trial work.