Chromosome Analysis of Dendrobium stockelbuschii and Dendrobium sylvanum Orchids

Abstract

Dendrobium stockelbuschii and Dendrobium sylvanum orchids are in great demand in Indonesia because of their uniqueness. Plant breeders keep trying to breed this orchid to maintain its uniqueness. Cytological information of D. stockelbuschii and D. sylvanum helps plant breeders in the breeding process. This research aims to determine the cytological characteristics such as chromosome number, size, shape, and karyotype. This study was conducted at the Plant Breeding Laboratory, Faculty of Agriculture, Sebelas Maret University. Data analysis was carried out descriptively based on chromosome observations. The results show that both orchid species have several chromosomes 2n = 38. The average chromosome length in D. stockelbuschii was 1.84 ± 0.52 μm to 2.05 ± 0.54 μm and in D. sylvanum was 2.32 ± 0.64 μm to 2.60 ± 0.68 μm. D. stockelbuschii and D. sylvanum had an average karyotype pattern of 2n = 2x = 38 = 18m + 1sm. The intrachromosomal asymmetry index (A1) value in both species tends to be metacentric, while the interchromosomal asymmetry index (A2) value in all species shows relatively tiny deviations in chromosome size.