Effects of plant growth regulators on seed germination and callus induction of Hylocereus costaricensis

Dragon fruit (hylocereus costaricensis) belongs to the family cactaceae and are climbing vines which have received worldwide attention in recent years. however,there are still lack of information on the protocols for the establishment of in vitro culture system. in the present study,seed germination percentage were determined by culturing seeds on semi-solid murashige and skoog medium (ms) supplemented with 1 ppm 6-benzylaminopurine (bap) together with either 0,0.5 or 0.8 ppm of indole-3-butyric acid (iba). germination percentage was the highest by using plant growth regulators (pgrs) combination of 1 ppm bap and 0 ppm iba (93.33%). subsequently,the cotyledons from seedlings of the germinated seeds were used for subsequent callus induction. small pieces of cotyledons were excised and cultured on ms medium fortified with 0.45,0.9,1.8,2.7,3.6,and 4.5 ppm of 2,4-dichlorophenoxyacetic acid (2,4-d) together with either 0,0.9 or 1.8 ppm of bap. callus induction percentage was highest using the plant growth regulators (pgrs) combination of 3.6 ppm 2,4-d and 1.8 ppm bap (75%). hence,3.6 ppm of 2,4-d and 1.8 ppm bap was the best combination for callus induction of hylocereus costaricensis. © 2016,pakistan botanical society. all rights reserved.