Abstract:

The aim was to study the mechanism of continuous regeneration of ryegrass. By pot culture, the study investigated the improving continuous regeneration of ryegrass in terms of the influence of roots on leaves under frequent defoliation. The study consisted of four treatments: (1) no root breaking without spraying cytokinin, (2) root breaking without spraying cytokinin, (3) no root breaking with spraying cytokinin, and (4) root breaking with spraying cytokinin. The results showed that root breaking or frequent defoliation resulted in low biomass of the newly grown leaves and roots. Frequent defoliation increased gibberellic acid (GA) and abscisic acid (ABA) content, decreased indole-3-acetic acid (IAA) content and decreased the ZR content in newly grown leaves. Spraying with exogenous cytokinin promoted the increase in ZR content and newly grown leaf biomass under frequent defoliation. There were a significant positive correlation between ZR content and biomass in newly grown leaves under frequent defoliation. In general, under frequent defoliation cytokinin plays an important in improving continuous regeneration of ryegrass.