Contributions to the Cytotaxonomy of the Commelinaceae. Gibasis linearis and its allies |
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Authors: | KEITH JONES FLS SUSHILA BHATTARAI DAVID R HUNT |
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Institution: | Jodrell Laboratory, Royal Botanic Gardens, Kew, Richmond, Surrey TW9 3DS;The Herbarium, Royal Botanic Gardens, Kew, Richmond, Surrey TW9 3AB |
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Abstract: | Species of the Gibasis linearis alliance collected in Mexico in 1976 are shown to have a chromosome constitution of x = 6, but x = 5 has also been found in some populations of G. rhodantha and G. speciosa. These two basic numbers are associated with distinctive karyotypes, 2M + 4A and 3M + 2A respectively, which show a Robertsonian relationship with each other. The existence of 2n = 22 in G. speciosa , combining both basic numbers at the amphidiploid level provides evidence of pairing between metacentrics and acrocentrics in such a way as to substantiate the view that fusion or fission of chromosomes is responsible for the modification of basic number. This survey provides a basis for other studies which will determine the chromosome relationships of the species irrespective of chromosome number in this family. |
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Keywords: | Commelinaceae cytotaxonomy Gibasis karyotype meiosis Mexico mitosis Robertsonian change |
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