STUDIES ON CHROMOSOME VARIATION IN VANDA SPECIES OF ORCHIDACEAE

Abstract

Chromosome analyses on different species of Orchidaceae namely, Vanda alpine Lindl, Vanda amesiana Reichb.f. Vanda coerulea Griff, Vanda coerulescence Griff, Vanda cristata Lindl, Vanda densiflora Lindl and Vanda hookeriana Reichb. f.. Deviant report as against the previous records of chromosome numbers have been made in Vanda alpine Lindl, Vanda amesiana Reichb.f. Vanda coerulea Griff, Vanda coerulescence Griff, Vanda cristata Lindl, Vanda densiflora Lindl and Vanda hookeriana Reichb.f.a. In all other species studied the present report of chromosome numbers are in correlation with those of earlier reports. The first record of chromosome number has been made in 2 species namely Vanda coerulescence Griff 2n-42, Vanda cristata Lindl 2n–40 and Vanda densiflora Lindl 2n-42. Most of the species of Vanda alpine Lindl 2n-38, Vanda amesiana Reichb.f. 2n–38, Vanda hookeriana Reichb.f. 2n–38 and Vanda coerulea Griff 2n–42. Vanda cristata 2n–40, Vanda densiflora 2n-42. Chromosome should have been originated by aneuploidy. The study of karyotype analyses shows that each and every species has a distinct karyotype. Therefore, karyotype alternations of chromosomes may have also play important role in speciation along with aneuploidy.