Analysis of Chromosome Morphology and Possible Means of Speciation in Jasminum

抄録

A thorough study of the karyotypes has been performed on fourteen different species and varieties of Jasminum in order to fill this lacuna in our knowledge of the cytology of this genus. Improved techniques, involving the use of Aesculine, have been standardized for this purpose. The absence of any detailed study on this aspect has been attributed mainly to the limitations of the methods adopted previously.
A general resemblance has been noted in the chromosome morphology between species of Jasininum, indicating that the genus represents a natural assemblage. The different species and varieties have been found to differ from each other in minute details of the karyotype. This fact has been regarded to suggest the important role played by structural alteration of chromosomes in evolution. As each and every species or variety is characterized by a distinct karyotype, the significance of this study in the identification of species has been emphasized.
The minor part played by polyploidy and specially, allotetraploidy, before the species concerned lost its capacity for sexual reproduction, has also been pointed out.
Variation in chromosome complements has been noted in the same somatic tissue containing normal nuclei and, as sexual propagation is mostly ineffective in this genus, the role of such somatic mutations in speciation of this genus through asexual means has been suggested.