title: Abnormal male meiosis explains  pollen sterility in the polyploid medicinal plant Pinellia ternata (Araceae).
abstract: Pinellia  ternata is an important traditional Chinese medicinal plant.  Its different populations in China have various ploidy levels, based on x =  13, as well as extensive aneuploid series. The microsporogenesis process was  observed in specimens from three populations from three regions of Hubei  Province; they were characterized by normal and abnormal meiotic divisions in  pollen mother cells (PMCs) at all stages simultaneously. Meiotic abnormalities  including univalents/multivalents, chromosomal laggards/bridges and micronuclei  appeared in about 50% of the PMCs, together with abnormal cytokinesis.  Chromatin/chromosome transfer between meiocytes occurred only during the first  division, at low frequency; this might contribute to these meiotic  abnormalities. Although the remaining 50% of the PMCs presented normal  cytological behavior, pollen fertility was only about 2%. These results provide  cytological explanations for its low seed-set and the general use of asexual  reproduction through tubers and bulbils; it also explains the wide variations  in chromosome number.
authors.affiliation: Institute of Medicinal Plants, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, PR China.
authors.forename: Y
authors.initials: Y
authors.lastname: Liu
authors.forename: R-K
authors.initials: RK
authors.lastname: Hui
authors.forename: R-N
authors.initials: RN
authors.lastname: Deng
authors.forename: J-J
authors.initials: JJ
authors.lastname: Wang
authors.forename: M
authors.initials: M
authors.lastname: Wang
authors.forename: Z-Y
authors.initials: ZY
authors.lastname: Li
mesh_terms: D002681:China; D002869:Chromosome Aberrations; D032461:Chromosomes, Plant / Q000235:genetics*; D048749:Cytokinesis; D008516:Medicine, Chinese Traditional; D008540:Meiosis; D030021:Pinellia / Q000235:genetics*; D051479:Plant Infertility; D010946:Plants, Medicinal / Q000235:genetics; D011058:Pollen / Q000235:genetics; D011123:Polyploidy