3.3 Sowing M. zehntneri seeds in vitro under different concentrations of plant growth regulators
The germination percentage of M. zehntneri seeds using in vitro conditions in a culture medium was 74% (Fig. 4), higher than observed using the same light conditions in the previous experiment with Petri dishes and filter paper (61.3%).
Seed imbibition in Ethephon solution as a pre-treatment resulted in a significant and striking increase in the percentage of in vitrogerminated seeds of M. zehntneri . The best treatment and response of seeds to Ethephon was reported in the culture medium without phytoregulators, which resulted in 98% seeds germinated (Fig. 4). In the control culture medium without the pre-treatment with Ethephon, the germination rate was only 76% (Fig. 4). The pre-treatment of seeds with Ethephon also promoted faster seed germination, with the greater number of seeds germinated within 11-14 days, compared to the control (18 days) (Fig. 5) and the highest GSI (2.93) compared to untreated (2.14) and the other plant growth regulators (BAP, GA3 or BAP+GA3) added to the culture media (Fig. 6).
Discussion