Abstract:

Two new varieties, ‘Dajinhong’and ‘Longshangxiongying’ of Dahlia pinnata were used as the experiment material to study, effects of CCC on the phenotype indices of the Dahlia, the content of IBA, IAA and the activity of related enzyme (POD and IAAO) in dahlia leaves. The result indicated that CCC could affect these morphological and physiological indices. The plant was dwarfed significantly, the stem and flower diameter increased, the activity of POD and IAAO improved, and the contents of IBA and IAA changed significantly. The correlation analysis showed that IBA content was negatively correctied with IAA contents and POD activity. IAA content had negative correction with the activity of POD and IAAO. There was positive correction between the activity of POD and IAAO activity. In addition, the CCC effects increased with the concentration. These indicated that CCC had different effects on the content of IBA and IAA, The function of two endogenous hormones was significantly different. IAA affects the growth and development of plants, IBA has close relationship with the plant resistance. POD and IAAO had different impacts on the content of IAA and IBA because of variation distinction of cultivars. A spray treatment of 3 000 mg·L CCC had the best dwarfing effect in the production when the dahlia’s plant height was 20 cm.

Key words: Dahlia pinnata, CCC, IBA, IAA, related enzyme activity