| Summary: | 碩士 === 國立中興大學 === 園藝學系所 === 94 === In this study poinsettia ‘Freedom’ and ‘FO 90-3’ clone were used. Mini poinsettias were produced by single-node cuttings cultured in a closed liquid culture system and combined with chlormequat paste. Shoot tip cuttings cultured in soilness lanolin mixture were used as control.
When single-node cuttings treated with NAA 0.5 g/kg or IBA 1 g/kg powder, the rooting rate and the sprouting rate of lateral bud were above 96%. As conc. of auxin increased, the sprouting rate of lateral bud decreased. Also, rooting and sprouting were affected by node position. Basipetally, cuttings from 4th to 7th nodes with unfolded leaves had 100% rooting rate and sprouting rate. Single-node cuttings were culture in Hoagland solution at different strength. Double strength of Hoagland solution decreased plant height, however, the canopy diameter and colored area were the same as those of cuttings cultured in Hoagland solution. Therefore the ratio of canopy diameter/plant height could reach to 2.23. Decreasing phosphorus conc. to half strength also decreased 10% of plant height, canopy diameter and colored area. To compare with the culture system for single-node cuttings, cuttings in hydroponics system grew higher than in soilness mixture, although the intern ode of plant in hydroponics system was less than 0.8 cm. Therefore, the ratio of canopy diameter/plant height was larger than 2.1. When shoot tip cuttings or single-node cuttings cultured in hydroponics system, the former was 2 cm taller and 4-5 nodes more than the later. When 1 g/kg of chlormequat paste was painted on lateral bud of single-node cutting, the rooting rate and the length of the longest root were enhanced. However, when lateral bud was painted chlormequat paste of 2 g/kg the area of bracts and colored leaves decreased.
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