Bull. Spec. CORESTA Symposium, Winston-Salem, 1982, p. 79, AP3, ISSN.0525-6240

Dihaploid-type isogenous Lines and their use in tobacco quality improvement

Central Research Station for Tobacco Culture and Industrialization, Bucharest, Romania.
Isogenous lines were obtained by doubling the chromosomal set of androgenetic haploids achieved byïn vitro"anther culture derived from inter- and intraspecific Nicotiana hybrids that were in the F1-F4 generation. Dihaploid genomes that include genetic information from Nicotiana glutinosa and Nicotiana glauca are used as initial material for quality improvement to obtain virus-resistant tobacco forms. Tabacum-type dihaploid genomes having some useful characteristics were checked in the last steps of the improvement process for their acceptance as new varieties. Virginia 501 and 496 and the semi-oriental 504-type line are remarkable for their productivity and quality index. Cytogenetic analysis of dihaploid genomes reveals the stability of chromosome number and morphology, as well as a quite normal meiotic division.