Effect of CO2 enrichment and sugar-free medium on survival and growth of turfgrass regenerants grown in vitro

摘要

Regeneration culture systems using 2 types of bioreactors were developed for Festuca arundinacea (tall fescue) and Zoysia japonica (zoysiagrass), utilizing callus induced from mature seeds. Regenerants of F. arundinacea and Z. japonica were efficiently produced using an aeration-agitation type bioreactor and a rotating drum type bioreactor, respectively. Regenerants were harvested and cultured in vitro during the preparation stage either on 1/4 strength N6 gellan gum (4 g/litre) medium without sucrose or with 30 g sucrose/litre, and under CO2 concentrations of 0.4 or 50 mmol/mol, a photoperiod of 24 h per day and a photosynthetic photon flux density of 125mol m-2 s-1. Shoot and root lengths and shoot and root dry weights (DW) of F. arundinacea regenerants and the root DW of Z. japonica regenerants were greater on the medium with sucrose than those on the medium without sucrose, regardless of CO2 concentration. The survival percentage, shoot number and shoot length of Z. japonica regenerants growing on the medium without sucrose at a high CO2 concentration were the highest among all the treatments.