Effects of chlormequat chloride on the growth and endogenous hormones contents of Dahlia pinnata and their correlation analysis

A field experiment was conducted to determine the effects of chlormequat chloride (CCC) on the growth and endogenous hormones contents of Dahlia pinnat varieties, Longshangxiongying. The results of this study showed that the CCC significantly decreased the plant height and internode length, increased the leaf area, stem diameter, flower diameter and petal number, lengthened the flowering period, reduced the IAA and GA3 content and increased the ABA contents at vegetative growth stage; however, the CCC increased the IAA and GA3 content and reduced the ABA content at reproductive growth stage, and the changeable trend of these parameter strengthened as the CCC concentration increased. The correlation analysis results showed that the plant height was significantly positive correlation with the IAA and GA3 contents and was negative correlation with ABA contents at vegetative growth stage, and the internode length was significantly positive correction with IAA contents; the stem diameter was negative correlated with the GA3 contents and the leaf area was significantly negative correlation with the GA3 contents and was positive correlation with ABA contents. The flowering period and flower diameter was significantly positive correlation with the IAA and GA3 contents, and was negative correlation with ABA contents; the petal number was positive correlation with the GA3 content at reproductive growth stage. This study suggested that the optimal concentration of CCC was 3 000 mgL-1 CCC.