CYTOGENETIC STUDIES IN THE GENUS HELIANTHUS L

The genus Helianthus belongs to the subdivision Tubiflorae and the tribe Heliantheae of the family Compositae. The genus comprises about 100 species, which are mostly North American (Bailey 1928, 1929). The different species of the genus are grown for ornamentals, oil crops, forage crops, dyes and even for vegetables. Of the known 100 species of Helianthus, only about 25 species have so far been cytologically examined and no karyotypic studies were ever undertaken in this important genus. This suggests a need and scope for cytological work in the genus. We, therefore, undertook a cytological study in the genus, utilizing as many species as we could procure. The present paper describes results of meiotic studies in 28 taxa including 13 species of Helianthus, 14 varieties of H. annuus and variety of H. debilis. The paper also describes results pertaining to interspecific hybrids obtained using six different Helianthus species. © 1979, Japan Mendel Society, International Society of Cytology. All rights reserved.