期刊
HEREDITY
卷 87, 期 -, 页码 136-145出版社
NATURE PUBLISHING GROUP
DOI: 10.1046/j.1365-2540.2001.00862.x
关键词
Centaurea; controlled cross; hybridization; null allele; polyploidy; tetrasomic inheritance
In eastern Belgium. diploid and tetraploid knapweeds (Centaurea jacea L. s. l.) show a parapatric distribution with a contact zone. To compare the success of inter- and intra-cytotype crosses, and to investigate the pattern of allozyme segregation, controlled crosses involving plants from this contact zone were performed. Polysomic inheritance at two loci was observed in tetraploids, suggesting an autopolyploid origin. Two crosses allowed the detection of double reduction events in tetraploids at one locus. but no such event was detected among the 217 progenies. Null alleles were detected in tetraploids at two loci. Both cytotypes were highly self-incompatible. Inter-cytotype crosses were much less successful than intra-cytotype crosses in terms of seed set (five-fold reduction) and germination rates (three-fold reduction), suggesting a 'triploid block' effect. Progenies from inter-cytotype crosses most often had the maternal cytotype and resulted from selfing or pollen contamination. However. six triploids were detected. The significance of these results for the understanding of the geographical distribution of the cytotypes and inter-cytotype gene flow is discussed.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据