XVI International Botanical Congess

The regenerative capacity of Begonia x erythrophylla petiole explants is influenced by both photon fluence and the photoperiod in which donor plants are grown. When cultured on a shoot-inducing medium explants show a much higher regenerative capacity when the donors are grown at 50 µmol m-2 s-1 (PAR). Photoperiod also has a significant influence on regenerative capacity, but only when donors are grown at 500 µmol m-2 s-1. Our studies have shown that ability of explants to accumulate starch, during the first few days of culture, is critical for meristem formation. We have also found that the light environment, in which donors are grown, can influence the ability of explants to accumulate starch and hence form meristems