In vitro plant regeneration from protocorms-like bodies (PLBs) and callus of Phalaenopsis gigantea (Epidendroideae: Orchidaceae)

Phalaenopsis, with long arching sprays of flowers, are among the most beautiful flowers in the world. Phalaenopsis is an important genus and one of the most popular epiphytic monopodial orchids, grown commercially for the production of cut flowers and potted plants. Most of them have different and interesting morphological characteristics which have different value to the breeders. Phalaenopsis gigantea is one of the most difficult to grow and has the potential of producing beautiful hybrids. An efficient and reproducible method for large-scale propagation of Ph. gigantea using leaf sections has been developed. Leaf sections from in vitro young plants were cultured on New Dogashima Medium (NDM) supplemented with cytokinins (6-Benzylaminopurine (BAP), Thidiazuron (TDZ), and Kinetin (KIN), each at 0.01, 0.1, 0.5 and 1.0 mg/L) alone and in combinations with (auxins a-naphthaleneacetic acid (NAA), at 0.01, 0.1, 0.5 and 1.0 mg/L). The explants developed calli and protocorm-like-bodies (PLBs) within 6 weeks of culture. Treatment TDZ in combination with auxins was found to be the best for the induction of callus and PLBs. In vitro regeneration of Ph. gigantea PLB was achieved by exposure to light and transferring to hormone free NDM solid medium.Key words: Phalaenopsis, PLBs, new Dogashima medium, regeneration

Full Length Research Paper Plant regeneration of Michelia champaca L., through somatic embryogenesis

Michelia champaca L. is a woody ornamental tree species which has high commercial value to be used as a basic material for perfume, cosmetic, and medicine. The development of an efficient plant regeneration system for M. champaca is essential for the production of Champaca planting material and precondition for genetic manipulation. Plant regeneration systems of M. champaca through somatic embryogenesis derived from immature seed of M. champaca L. which was successfully developed in this study. MS medium supplemented with 2 mgL-1, NAA produced highest percentage of embryogenic callus formation of (43%). The embryogenic cells proliferated and formed somatic embryos (30%) after four to six months of culture in the same medium. Meanwhile, on germination of somatic embryos, hormone free of MS medium resulted in highest percentage of normal plantlets produced (45%) compared with other germination medium which is containing different GA3 concentrations with ranges from 1 - 8% somatic embryos germinated

Molecular characterization and phylogenetic relationships among and within species of Phalaenopsis (Epidendroideae: Orchidaceae) based on RAPD analysis

Random amplified polymorphic DNA (RAPD) analysis for 20 species of Phalaenopsis was conducted to determine their genetic distances and relationships. Among 20 different primers used for RAPD analysis, 10 primers showed polymorphism, and according to the primer type, 26 to 54 DNA fragments were amplified. A total of 414 polymorphic fragments were generated by 10 primers and used for correlation group analysis. The highest value of Similarity index was 0.28 between Ph. violaceamalaysia and Ph. violacea witte. The dendrogram resulting from UPGMA (Unweighted Pair Group Method using Arithmetic average) hierarchical cluster analysis separated the original species into threegroups: The first group had five species of Ph. violacea blue, Ph. belina, Ph. violacea malaysia, Ph. violacea witte, and Ph. gigantea; the second group included Ph. lamelligera, Ph. amabilis, Ph. parishii, Ph. labbi nepal, Ph. speciosa, Ph. lobbi yellow, Ph. venosa, Ph. hieroglyphica, and Ph. maculata; the third group consisted of Ph. minho princess, Ph. leopard prince, Ph. mannii, Ph. modesta, Ph. cornucervi and Ph. pantherina. RAPD markers can thus be successfully applied in this economicallyimportant group of orchids for the study of molecular characterization and relationships. The data acquired from this study could be used for identification and classification of other orchid genera andoriental Phalaenopsis

Detection of somaclonal variation by random amplified polymorphic DNA analysis during micropropagation of Phalaenopsis bellina (Rchb.f.) Christenson

Phalaenopsis bellina (Rchb.f.) Christenson orchid species are known for their beautiful flower shape, graceful inflorescence and fragrance. Protocorm-like bodies (PLBs) of P. bellina were induced from leaf segments. The PLBs were then subjected to proliferation using ½ strength Murashige and Skoog (MS) media with two subcultures at three months intervals. Twelve decamer random amplified polymorphic DNA (RAPD) primers were used to study somaclonal variation among the mother plant, the initially induced PLBs and proliferated PLBs after 3 and 6 months in culture. Eight out of twelve primers produced 172 bands with 18 polymorphic bands in all the treatments. The amplified products varied between 125 to 8000 bp. Among the primers used, P 16 produced the highest number of bands (29), while primer OPU 10 produced the lowest number (15). The range of similarity coefficient was from 0.83 to 1.0 among the different sub-cultures and mother plant (MP). It was found that minimal or no changes occurred between the MP and the PLBs produced after 3 months of induction. The induced PLBs were then subcultured for six months for proliferation and this resulted in about 17% dissimilarity with MP. It is reported that micropropagation of P. bellina can be carried out successfully using ½ strength MS media for 6 months but further proliferation may result in somaclonal variation which might change the prolific characteristic of this orchids.Key word: Moth orchid, somaclonal variation, random amplified polymorphic DNA, protocorm-like bodies