Karyotype of Phaius tankervilleae and Phaius amboinensis orchid

Abstract

Phaius tankervilleae and Phaius amboinensis orchids are decorative orchids that have high ornamental value and are classified as endangered plants. Genetic information from the P. tankervilleae and P. amboinensis orchids will be useful for plant breeders to develop a strategy in the ornamental improvement program. The aim of the study was to determine the karyotype pattern of P. tankervilleae and P. amboinensis orchids. Chromosomes obtained from meristematic root tips of each species were used to construct a karyotype and idiogram used the squash method. The results showed that the chromosome numbers and karyotype formulae of P. tankervilleae was 2n=2x=44=44 m (metacentric) and P. amboinensis was 2n=2x= 46=44m+2sm (sub-metacentric). Intrachromosomal Asymmetry Index (A1) of P. tankervillae was 0,10 and P. amboinensis was 0,15, indicates that both of them tend to have a metacentric chromosome type. Interchromosomal Asymmetry Index (A2) of P. tankervillae was 0,37 and P. amboinensis was 0,34, indicates that both have sufficient varies in size of chromosomes.