IMPROVEMENT OF ARTIFICIAL MEDIUM FOR PASSIONFRUIT POLLEN GERMINATION

On the artificial medium, passionfruit pollen does not germinate without coating the surface of the medium with fluid pressed out of stigma. However, this method needs fresh stigmas at the time of using the medium and it is difficult to coat the surface uniformly. In this study, improvement of the preparation of artificial medium for passionfruit pollen germination was tried. Basal medium contained 2% agar, 30% sucrose, 0.02% boric acid and 0.10% calcium nitrate. To find the optimum number of stigma for mixing, fluid pressed out of 0, 0.5, 1, 1.5, 2, 3, 4 and 5 stigmas were added into 50 ml of the basal medium. The pollen germination on those medium was compared with the medium coated the surface with the fluid. Although coated medium showed the highest percentage of pollen germination (30.0%), the medium mixed with more than three stigmas showed significantly higher germination percentages (14.0~17.0%) than other medium with two or less stigmas (2.7~6.0%). To observe the stability of the medium after repeated boiling, the medium supplemented with stigma fluid and the medium without fluid were boiled repeatedly until 15 times. The medium without fluid was coated with fresh fluid pressed out of stigma. The pollen germination was observed on the coated medium by the 15^th boiling, while on the supplemented medium boiled more than 12 times no pollen germinated.