Karyotype traits in Romanian selections of edible blue honeysuckle

Large morpho-anatomical and biochemical variability was evidenced in all Lonicera caerulea L. provenances. The knowledge of chromosome constitution is of basic importance in this context of elevated phenotype heterogeneity and represents a necessary step in breeding programs. The Romanian selections are tetraploid (2n = 4x = 36). Chromosomes are small-sized ( 3.5 μm), and lengths of haploid complements are close (28.97–29.05 μm). Only the Lc SL15 complement is larger (33.89 μm), possibly due to lower chromatin condensation. Karyotypes contain metacentric (85%–100%) and submetacentric chromosomes. According to asymmetry indexes (AsI% = 55.01–59.89, TF% = 40.13–44.98, A1 = 0.17–0.29, A2 = 0.23 0.30) and to Stebbins’ classification, the karyotypes fall into 1B and 2B categories, considered relatively symmetric and primitive in this system. In the idiogram constructed on average values of cytogenetic parameters of all analyzed selections, the mean chromosome length is x– ± SE = 1.66 ± 0.07 μm, ranging from 2.73 ± 0.20 to 1.10 ± 0.02 μm. The mean relative length is between 9.05 ± 0.30 and 3.70 ± 0.12. One submetacentric chromosome pair is present. As a result, the general karyotype formula is K(2n) = 36 = 34 m + 2 sm.