关键词: 毛华菊, 不同瓣型, 叶片, 再生体系, 茎间薄层

Abstract: Chrysanthemum vestitum, one of the closely related hexaploid wild species of cultivated C. × morifolium, has typical flat, tubular and mixed floret forms in its natural population, and is a typical material for studying the petal variation in chrysanthemum. The development progress of its ray floret is affected by key differential genes, but the lack of stable and efficient regeneration systems of different floret forms has restricted the study of petal type-related genes in C. vestitum. In this paper, the authors used three floret forms of C. vestitum collected from FuNiu Mountain in Henan Province to establish regeneration systems using leaves and transverse thin cell layer (tTCL) as explants. The results showed that the optimal medium for callus induction and adventitious buds differentiation was MS+1 mg∙L–1 NAA+2 mg∙L–1 6-BA with leaves of flat floret form as explants, and the callus induction rate was 100% at 20 days of inoculation. The differentiation rate of adventitious buds was 100%. The optimal rooting medium was 1/2 MS+0.2 mg∙L–1 NAA, and the rooting rate of regenerated seedlings was 100%. The optimal leaf regeneration system of flat floret strain was suitable for tubular floret and mixed floret strains. The differentiation rates of adventitious buds were 83.46% and 91.67%, respectively, and the rooting rates were 100%. The flowering plants were observed after transplanting, and it was found the flower types of the regenerated plants with three different floret forms obtained by the leaf regeneration system were stable, which provided a technical method for the subsequent analysis of the morphological variation mechanism of ray florets by using different floret forms of C. vestitum.

Key words: Chrysanthemum vestitum, different floret forms, leaf, regeneration system, tTCL