Cytotaxonomic Relationships and the Role of Apomixis in Speciation in Buffelgrass and Birdwoodgrass1
- J. C. Read and
- E. C. Bashaw2
A sexual buffelgrass clone (Cenchrus ciliaris L. = Pennisetum ciliate (L.) Link.), heterozygous for method of reproduction, was crossed with apomictic birdwoodgrass (C. setigerus Vahl.) to determine the relationship of these species. The F1 population contained both sexual and obligate apomictic plants representing a rather complete intergradation between the parents. High fertility of the hybrids and homology of their chromosomes showed that the parents are closely related and undoubtedly belong to the same genus. Some of the hybrids were so different from either parent that populations from them might easily be mistaken for new species. With selfing, average fertility of apomictic hybrids was nearly three times that of sexual hybrids. The diversity of hybrids resulting from brief contact between sexual and apomictic plants and the superior fertility of the obligate apomicts illustrate the dynamic evolutionary potential of apomixis.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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