CYTOGENETIC STUDIES ON SEVERAL HIPPOPHAƠ RHAMNOIDES L. GENOTYPES

Sea-buckthorn (Hippophae 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 Bacău county - Dospineuti, uerpeni 11, uerbăneuti 4, Sfiutofca 18, and to one genotype of the Danube Delta - Sfântul 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 uerbăneuti 4 genotype (53.13), and the lowest – in uerpeni 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.