title: Reticulate evolution of the hybrid produced artificially by crosses between Osmunda banksiifolia and Osmunda lancea.
abstract: Although ferns have been developed by hybridization and chromosome doubling, no natural polyploidy has yet been recorded in Osmundaceae. So, we produced hybrids artificially by crosses between Osmunda banksiifolia (2n = 2x = 44) and Osmunda lancea (2n = 2x = 44), and investigated their sporogenesis. From the O. banksiifolia x O. lancea hybrid with 44 univalent chromosomes, allotetraploids with 44 bivalent chromosomes were produced by chromosome doubling, and allotriploids with 22 univalent chromosomes and 22 bivalent chromosomes were then produced by back crosses. The results show when and how chromosome doubling occurs in hybrids. The success of artificial hybridization between O. banksiifolia and O. lancea, did not, however, reflect any product of natural hybridization between the two species.
authors.affiliation: Nishio Nursing College, Nishio, Aichi, Japan. fernkawa@mb.ccnw.ne.jp
authors.forename: Suzue M
authors.initials: SM
authors.lastname: Kawakami
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Kondo
authors.forename: Shogo
authors.initials: S
authors.lastname: Kawakami
mesh_terms: D005075:Biological Evolution; D002678:Chimera / Q000235:genetics*; D032461:Chromosomes, Plant / Q000648:ultrastructure; D003433:Crosses, Genetic; D029624:Ferns / Q000235:genetics*; D006824:Hybridization, Genetic; D011123:Polyploidy