CYTOGENETIC STUDIES ON SEVERAL HIPPOPHA RHAMNOIDES L. GENOTYPES

Sea-buckthorn (Hippopha rhamnoides (2n=24)) is a dioecious plant with a very obvious morpho-physiological polymorphism. This species is one of the most valuable fruit-bearing shrubs of the spontaneous and also of the cultivated flora, due to its content of biologically active substances of its leaves, fruit and shoots. The research has been accomplished on root apical meristems from germinated seeds that belong to four genotypes characteristic for Bac u county - Dospineúti, ùerpeni 11, ùerb neúti 4, Sfiútofca 18, and to one genotype of the Danube Delta - Sfantul Gheorghe 5. Cytogenetical studies evinced that the mitotic index (MI) was high, and it varied with the genotype. The highest MI was evinced in the ùerb neúti 4 genotype (53.13), and the lowest – in ùerpeni 11 (40.08). Cell distribution per mitotic phases is approximately the same, the highest percentage was represented by cells in prophase, followed by metaphases, telophases and anaphases. There is a rather high frequency and a quite large spectrum of chromosomal aberrations identified in this species (with variations due to the 5 different genotypes). Of all the chromosomal aberrations evinced during the ana-telophases of mitotic root apical meristems (bridges, delayed chromosomes, expelled chromosomes, fragments, micronuclei), the highest frequency was represented by ana-telophases with bridges. There has been noticed the presence of chromosomal abnormalities in metaphasic and prophasic cells.