Strong Allelopathic Activities of Leaves and Cultured Cells of <i>Spiraea thunbergii</i> Assayed by the Protoplast Co-Culture Method with Digital Image Analysis: Evaluation of <i>Cis</i>- and <i>Trans</i>-Cinnamic Acid as Allelochemicals

The inhibitory allelopathic activities of leaves and leaf-origin suspension cultured cells Spiraea thunbergii, putative allelochemicals, cis- trans-cinnamic acid, were investigated by the protoplast co-culture method with digital image analysis (DIA-PP method) using lettuce as a recipient. optimal conditions 2,4-dichlorophenoxyacetic acid (2,4-D) benzyladenine (BA) for cell division S. thunbergii protoplasts first examined 50 μL liquid MS basal medium containing 3% sucrose, 0.8 M mannitol in 96-well culture plate. hormonal condition co-culture, 1 μM 2,4-D plus 0.1 BA, which was growth, sub-optimal protoplasts. Effects on three stages i.e., wall formation, division, yellow pigment accumulation, examined. Protoplasts leaf strongly inhibited growth at stage (100% inhibition 80 - 100 × 103 mL-1), but not so much other two stages. Both showed strongest formation stage, 100% μM. These results compared those obtained seedling test, different plants, their allelochemicals studied DIA-PP method.