The Journal of Heredity 1988:79(3):175-178
© 1988 The American Genetic Association 79:175-178
research-article |
The Use of Tangled Pachytene Chromosomes for Karyotype Analysis in Atylosia
Department of Agronomy, Waite Agricultural Research Institute, University of Adelaide Glen Osmond, S.A., Australia
Department of Agriculture, University of Queensland St Lucia, Australia
Address reprint requests to Prof. Britten, Department of Agriculture, University of Queensland, St. Lucia 4067, Queensland, Australia.
Abstract
Species of plants in which pachytene chromosomes are not readily Identifiable because of chromosome tangling present difficulties for karyotype studies. A method of analysis that overcomes this problem was used to prepare karyotypes of two Australian relatives of the pigeon pea (Cajanus cajan): Atylosia acutifolia and A. pluriflora. Quantitative description of the major chromomeres of the chromosomes, together with keys and idiograms, has made it possible to characterize and identify chromosomes with the microscope. The major chromomeres of Atylosia were larger than those of pigeon pea, the largest being a 12-part cluster for A. acutifolia, whereas the largest for A. pluriflora was a 6-part cluster. The chromomere patterns of the two accessions of A. acutifolia showed large differences, suggesting that these two accessions may be representative of subspecies. It is anticipated that our data on chromomere patterns of Atylosia will find application in the identification of chromosomes in interspecific hybrids between pigeon pea and Atylosia. The method also should be applicable to other species in which chromosome tangling makes karyotype analysis difficult.