Meiotic studies in species hybrids of the solanum nigrum complex
Rao, G.R.; Kumar, A.
Cytologia 49(1): 33-38
ISSN/ISBN: 0011-4545 Accession: 005874119
Morphology and meiosis of S. retroflexum (2n = 48) and S. nodiflorum ssp. nutans (2n = 24), and of their hybrids (F1, 2n = 36) and synthetic polyploids (C2, 2n = 72) were studied in detail. The hybrids showed irregular meiosis, they were sterile and did not set fruit. The synthetic polyploids showed mostly normal meiosis; pollen fertility was much increased. They set fruit and seed spontaneously. Polyploidy and structural differences of chromosomes are apparently the main factors in genetic isolation of the species. Based on chromosome behavior at meiosis then genomic constitution of S. retroflexum, S. nodiflorum ssp. nutans, hybrids and synthetic polyploids is represented as AABB, A'A', AA'B and AAA'A'BB, respectively.