Morphometric pattern of somatic chromosomes in three romanian seabuckthorn genotypes

Abstract

The somatic chromosomes and karyotype traits of three Romanian genotypes (coded as CB-1, S-16, L-4) of Hippophae rhamnoides L. have been studied. Diploid chromosome number is 2n = 24. The karyomorphological data show that the complements have small chromosomes (1.33 ± 0.014 – 2.80±0.01 μm, for CB-1 genotype; 1.13 ± 0.029 – 2.90 ± 0.029 μm, for S-16; 1.15 ± 0.099 – 2.88 ± 0.024 μm, for L-4 genotype) and the length of haploid complements is 23.97 μm, for CB-1, 22.20 μm, for S-16, 21.73 μm, for L-4. In CB-1 and S-16 male genotypes, the putative Y-chromosome has larger sizes than X-chromosome and it is of metacentric type (CI = 45.77, r = 1.18, for CB-1; CI = 46.22, r = 1.15, for S-16). The L-4 female karyotype is constituted by twelve pairs of morphologically similar chromosomes. The karyotype formulae are 2n = 24 = 13m + 11sm (putative male: 22 + XY), for CB-1 genotype, 2n = 24 = 18m + 6sm (putative male: 22 + XY), for S-16 genotype, respectively 2n = 24 = 22m + 2sm (L-4 genotype, considered as female: 22 + XX). The small size of chromosomes (< 3μm), the presence of only two morphometric chromosome types and preponderance of metacentrics confer a relatively high degree of symmetry to the studied karyotypes. Our results show a low intraspecific karyotype variation. © 2011 Taylor and Francis Group, LLC.