The Chromosome of Phalaenopsis spp. and Doritaenopsis sp. Hybrid Induced by Colchicine

Abstract

One way to improve the genetic diversity of orchid plants is by polyploidization using the antimitotic compound colchicine. This research was conducted to determine the ploidy level in several types of hybrid orchids (Phalaenopsis spp. and Doritaenopsis sp.) that applied 1,000 mgL-1 colchicine and to obtain polyploidy orchid yields to improve the genetic diversity of orchid plants. This research was carried out on August 2021 - March 2022 in the Screen House Faculty of Agriculture Universitas Sebelas Maret and Integrated Laboratory Universitas Sebelas Maret. The method of this research uses squash preparation for chromosome analysis with the preparation materials used the meristematic flower bud of Phalaenopsis Shu Long 'TS2904', Phalaenopsis Chain Xen Moment, and Doritaenopsis Shu Long Purple Queen x OX King '3545' which were not treated and has been treated with 1,000 mgL-1 colchicine. Orchid varieties that used as samples were three samples, then each sample had two treatments and was replication two times. There are twelve samples in all. The application of colchicine was made by wetting a cotton swab with 1 ml of colchicine solution in each treatment. Then the buds are wrapped with cotton and covered with carbon paper outside for two days. The results of this research showed that the Phalaenopsis Shu Long 'TS2904', Phalaenopsis Chain Xen Moment, and Doritaenopsis Shu Long Purple Queen x OX King '3545' orchids which were treated with 1,000 mgL-1 colchicine each underwent polyploidization into tetraploid with the number of chromosomes 2n = 4x = 76. Phalaenopsis Shu Long 'TS2904', Phalaenopsis Chain Xen Moment, and Doritaenopsis Shu Long Purple Queen x OX King '3545' have a relative length chromosome length, and have the same chromosome shape, namely metacentric.