Effects of organic compound and plant growth regulators on seed germination and growth of Doritis pulcherrima Lindl. in vitro

Abstract

Doritis pulcherrima Lindl. is one of the wild orchids of which the distribution has decreased in nature and endangered. In vitro seed culture by using plant tissue culture is a proper method to help increasing the numbers. The purpose of this research was to study the effect of organic compound and plant growth regulators on seed germination and growth of D. pulcherrima in vitro. Seeds were cultured on Vacin and Went (VW) basal medium. Experiments were performed in a 5×7 factorial in completely randomized design (factorial in CRD) 2 factors; Factor 1 capsule of D. pulcherrima with 5 treatments such as Pi102/1, Pi102/2, Pi119/1, Pi119/2 and Pu112. Factor 2 organic compound with 7 treatments such as no organic compound (control), 50, 100 g L-1 raw namwa banana powder, 50, 100 g L-1 cavendish banana homogenate, 50, 100 g L-1 potato homogenate. After 13 weeks of culture, there were only 3 capsules growth seed germination (Pi119/2, Pi102/2 and Pu112/1) and the highest percentage of seed germination was Pi119/2 on VW medium supplemented with 50, 100 g L-1 banana powder and 50 g L-1 potato homogenate gave the highest germination percentage at level 4 (75-100%). From the results, organic compound is a suitable culture supplement for D. pulcherrima seed germination and development compared to no organic compound. In addition, the effect of plant growth regulators on growth and development of D. pulcherrima protocorm were cultured on VW medium supplemented with different concentrations of control, 1, 2 and 3 mg L-1 BA and 0.01, 0.02 and 0.03 mg L-1TDZ. The result showed the control gave the highest number of leaves at 6.50, the number of protocorm at 3.67 and fresh weight of protocorm at 0.42 g. The protocorm and plantlet were induced after 10 of culture.