Effects of Explants and Growth Regulators on In Vitro Regeneration of Dragon Fruit (Hylocereus undatus Haworth)

The experiment was conducted at Plant Tissue Culture Laboratory, Experiment and Lecture Building - 2 (ELB-2), Department of Horticulture, Yezin Agricultural University (YAU) from 2016 to 2018. This study was carried out to investigate effects of explant types and to examine effects of different levels of plant growth regulators on in vitro regeneration of dragon fruit. The experiment was arranged in factorial RCB design with four replications and factor A was two kinds of explants; distal and proximal portions (7-10 mm) of shoot developed in vitro and factor B was five different levels of N-6 benzyl aminopurine (BAP) for shoot multiplication. For root induction, factor A was two types of explants; distal and proximal portions (7-10 mm) and factor B was three different levels of naphthalene acetic acid (NAA). According to the experimental results, in shoot multiplication, the maximum number of shoots per explant (4.42) and the longest shoot (1.39 cm) was obtained from proximal portion of shoot explants. The medium supplemented with 10 μM BAP was observed production of the highest number of shoots, shoot length and shoot fresh weight. In root induction, there was no significant effect of different explant types on number of roots, root length and fresh weight of plantlets. However, the maximum number of roots, root length and fresh weight of plantlets were found at 0.3 μM NAA containing media. By the results, it can be concluded that the proximal portion of shoot explant should be used in shoot multiplication and the medium containing 10 μM BAP is recommended. For root induction, the explants cultured on 0.3μM NAA containing medium is recommended for in vitro root induction stage