title: Cytomixis and meiotic  abnormalities during microsporogenesis are responsible for male sterility and  chromosome variations in Houttuynia cordata.
abstract: Houttuynia  cordata (Saururaceae) is a leaf vegetable and a medicinal herb  througout much of Asia. Cytomixis and meiotic abnormalities during  microsporogenesis were found in two populations of H. cordata with  different ploidy levels (2n = 38, 96). Cytomixis occurred in pollen mother  cells during meiosis at high frequencies and with variable degrees of  chromatin/chromosome transfer. Meiotic abnormalities, such as chromosome  laggards, asymmetric segregation and polyads, also prevailed in pollen mother  cells at metaphase of the first division and later stages. They were caused by  cytomixis and resulted in very low pollen viability and male sterility. Pollen  mother cells from the population with 2n = 38 showed only simultaneous  cytokinesis, but most pollen mother cells from the population with 2n = 96  showed successive cytokinesis; a minority underwent simultaneous cytokinesis.  Cytomixis and irregular meiotic divisions appear to be the origin of the  intraspecific polyploidy in this species, which has large variations in  chromosome numbers.
authors.affiliation: Institute of Medicinal Plants, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, PR China.
authors.forename: J-Z
authors.initials: JZ
authors.lastname: Guan
authors.forename: J-J
authors.initials: JJ
authors.lastname: Wang
authors.forename: Z-H
authors.initials: ZH
authors.lastname: Cheng
authors.forename: Y
authors.initials: Y
authors.lastname: Liu
authors.forename: Z-Y
authors.initials: ZY
authors.lastname: Li
mesh_terms: D002843:Chromatin / Q000235:genetics; D002869:Chromosome Aberrations; D020090:Chromosome Segregation / Q000235:genetics; D032461:Chromosomes, Plant / Q000235:genetics*; D048749:Cytokinesis / Q000235:genetics; D056130:Gametogenesis, Plant / Q000235:genetics*; D014644:Genetic Variation; D052859:Houttuynia / Q000235:genetics*; D008540:Meiosis / Q000235:genetics; D051479:Plant Infertility; D010946:Plants, Medicinal / Q000235:genetics; D011003:Ploidies; D011058:Pollen / Q000235:genetics
chemical_list: D002843:Chromatin