CHROMOSOME NUMBERS AND KARYOTYPES OF EURYCOMA LONGIFOLIA JACK AND EURYCOMA APICULATA A.W. BENN (SIMAROUBACEAE)

Abstract

Knowledge of chromosome cytology of the Eurycoma longifolia and Eurycoma apiculata was limited. The goal of this study was to investigate number, size, karyotype, and ideogram of chromosomes of E. longifolia and E. apiculata. The total of chromosome lengths, relative lengths, the ratio of long arm to short arm, and index of centrometric of somatic cell chromosomes were measured. The basic number of chromosomes of both species was x=7, chromosome counting displayed that E. longifolia and E. apiculata were diploid. Somatic chromosome numbers that are found were 2n = 2x = 14 for both species. The total chromosome length was ranged from 5.33 to 9.22 μm for E. longifolia and ranged from 4.15 to 10.52 μm for E. apiculata. Karyotype formula of E. longfolia and E. apiculata was 2n = 2x = 14 = 6m + 1sm and 2n = 2x = 7m, of which six pairs metacentric chromosomes and one pair submetacentric chromosome in E. longifolia and seven pairs metacentric chromosomes in E. apiculata respectively. Based on Eroglu’s classification, karyotype symmetric/asymmetric index (S/AI) value of the E. apiculata was 1.0 and was classified into perfectly symmetric karyotype that is characterized by completely metacentric chromosomes, while S/AI value of E. longifolia was 1.14 and was grouped as symmetric karyotype