Karyotypic studies in ecotypes of hippophaë rhamnoides l. from romania

Abstract

Sea buckthorn is a dioecious Eurasian shrub or small tree with largemorphological, biochemical and physiological variability, evidenced by the great number of studies. Cytogenetically, uncertainties exist on species basic number, ploidy level, and sex chromosomes. In this study, detailed cytogenetic measurements were carried out on six Romanian ecotypes belonging to Hippophaë rhamnoides L. ssp. carpatica Rousi, in order to establish the features and the symmetry degree of karyotypes, to evidencethe sex chromosomes, and to construct the idio-gram. The ecotypes have 2n = 24 metacentric and submetacentric chromosomes. An intraspecific variation exists concerning the proportion of these two morpho-types. The karyotypes have similar symmetry patterns (R = 2.57-2.89; TF% = 38.54-42.70; Asl% = 57.99-61.41; A1 = 0.27-0.35; A2 = 0.26-0.36) and belong to IB and 2B classes, being relatively high symmetric. Based onobtained results, we presume that the male sex chromosomes are heteromorphic, while in female plants are homomorphic. The Y chromosome is larger than X chromosome.