title: Variation of B chromosome associated with tissue culture in wheat-rye cross.
abstract: In vitro variation of B chromosomes was studied by examining the callus cells derived from the immature embryos from a cross of Chinese Spring wheat (Triticum aestivum L.) and Fin 7416 rye (Secale cereale L.) carrying two B chromosomes. In 40-d-old callus cells, the numbers of B chromosomes ranged from one to four in 65.6% of the cells observed. The distribution of B chromosome numbers was associated with the ploidy levels of the normal chromosomes (A chromosomes). The frequency of the cells with high numbers of B chromosomes (i.e., three or four B chromosomes) in the amphiploid cells with 56 A chromosomes was greater than those in the haploid cells with 28 A chromosomes. Although structural changes in the rye A chromosomes were observed, cytological observation and genomic in situ hybridization demonstrated that the rye B chromosomes were conserved in morphological appearance following tissue culture.
authors.affiliation: Cangzhou Academy of Agricultural and Forestry Sciences, Cangzhou 061001, China.
authors.forename: Bohong
authors.initials: B
authors.lastname: Tian
authors.forename: Hongjie
authors.initials: H
authors.lastname: Li
mesh_terms: D002678:Chimera / Q000235:genetics*; D032461:Chromosomes, Plant / Q000235:genetics*; D006238:Haploidy; D017403:In Situ Hybridization; D012434:Secale / Q000235:genetics*; D014908:Triticum / Q000235:genetics*