In vitro seed germination and multiplication of Calophyllum brasiliense

Abstract

Calophyllum brasiliense is a tree species with limited natural reproduction. In vitro germination may be an alternative for obtaining high-quality seedlings. Seeds were maintained in water before surface disinfestation and compared with control seeds (i.e. not immersed), without differences between treatments. HgCl2 used during surface-disinfestation reduced contamination rates of cultures. Fungal contamination was reduced with fungicide added to culture medium (23 to 6.4%), although bacterial contamination increased (24 to 36%). In another experiment, seeds were immersed in plant preservative mixture (PPM™) prior to surface disinfestation. By combining immersion for 48 h and 2 mL L-1 in culture medium, contamination was only 6%. Seeds immersion in GA3 prior to surface disinfestation reduced root formation as concentration increased. Germination rate and GSI were reduced, respectively, from 72% and 0.129 (24 h) to 60% and 0.092 (48 h) according to exposure time to GA3. After 90 days in multiplication medium containing benzylaminopurine, average number of shoots per nodal segment was 3.4. In conclusion, in vitro germination of C. brasiliense seeds is feasible in sucrose-free WPM medium and reaches a high contamination-free rate (up to 93.3%).