Plant hormones play important regulatory roles in crop growth， but the relationship and mechanism by which exogenous hormones induce the growth and development of Caucasian clover root tillers are still unclear. In this study， the effects of indole acetic acid （IAA）， cytokinin （CTK） and kinetin （KT） on the growth and development， endogenous hormone content and expression of related genes in Caucasian clover root tillers were compared. The results showed when the concentration of IAA was 8.0 mg·L^-1， exogenous IAA treatment had the strongest effect on the growth of Caucasian clover root tillers. And when CTK concentration was 100.0 mg·L^-1， exogenous CTK treatment had the strongest inhibitory effect on the growth of Caucasian clover. Exogenous KT treatment had the greatest effect on the growth of Caucasian clover root tillers while KT concentration was 0.5 mg·L^-1. Compared with the control group， exogenous hormone treatment had a significant effect on BRI1， AP2/ERF， KNOX， MAPK gene family， PAL， POD and other related genes. In conclusion， 8.0 mg·L^-1 IAA and 0.5 mg·L^-1 KT work best. This study provides a practical guidance for the artificial propagation and rapid grassland planting of Caucasian clover.

Caucasian clover  /  Plant hormone  /  Complex hormone  /  Gene family