Clonal Propagation of Phalaenopsis

Abstract

Phalaenopsis was clonally propagated by use of in vivo and in vitro methods. In vivo, plantlets formed naturally on the node and tip of inflorescence, or root. Application of N-6-benzyl adenine to exposed buds on the inflorescence spike to induce plantlet formation was not very successful. Rapid clonal propagation was successfully accomplished by use of in vitro culture techniques. Explants from the nodal buds of inflorescence were the most suitable material for culture, although apical and axillary buds from the stem could also be used. When basal nodes from inflorescences after flowering or young inflorescences were cultured in basal media (BM = Vacin and Went 4- 15% coconut water), one to four plantlets rather than protocorm-like bodies (plbs) were obtained from a single node. In order to produce more plantlets other plant parts such as leaf, stem and root were separated and cultured in various media. Plantlets were produced from stem and leaf cultures in Vacin and Went with 50% coconut water without sucrose (VW 4- 50%CW-Su). When stems and roots were cultured in basal medium + 1 ppm 2,4-dichlorophenoxyacetic acid (BM 4- 1 ppm 2,4-D) tumors were produced. The origin of tumor was endogenous. Protocorm-like bodies (plbs) and plantlets were produced on tumors when 2,4-D and sucrose were omitted from the medium. Upon culturing shoot tips in constantly agitated liquid BM for one month and transfer to agar medium for another month, plbs were produced. An indefinite number of plantlets could be obtained through method that produce plbs. To promote multiplication and differentiation of plbs into plantlets sucrose was removed from the medium. Then for optimum growth of plantlets, sucrose was again added to the medium. Subculture of plbs at one leaf stage resulted in production of new plbs on the original plb and on young leaf. Usually a cell in the epidermis divided anticlinally forming two protruding cells. Further divisions of these meristematic cells formed a globular plb. Cells on one side of the globular structure enlarged while cells in the other portion remained meristematic. This meristematic area organized a shoot tip before root initial.