Effect of substrate and gibberellic acid (GA3) on seed germination in ten cultivars of Opuntia sps.

The seeds of Opuntia sps show low germination capacity and high latency, so this studycompares different inert and synthetic substrates in vitro with the addition of gibberellic acid(GA3) to stimulate seed germination in ten cultivars of Opuntia sps. (O. megacantha, O.amyclaea, O. streptacantha, O. albicarpa and O. ficus-indica). The photoperiod 16/8 h,light/darkness had a positive stimulating effect on the seed germination rate, while an inertsubstrate (pumice:peat moss:sand, 1:1:1 v/v) showed on average 20% germination. The useof in vitro Gamborg medium increased the germination rate to 40%. The addition of 25 mg L-1gibberellic acid (GA3) to Murashige and Skoog (1962) medium, prepared to ¼ basal saltconcentration, increases the germination rate across all cultivars, up to 90% at four weeks.GA3 was shown to play an important role in breaking the latency of the seed, and increasedamylolytic activity during seed germination in Opuntia sps.