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Abstract

Random amplified polymorphic DNA (RAPD) and single-strand conformation polymorphism (SSCP)
analyses were employed for investigating genetic relationships of three Athrotaxis D.Don species. Twenty-nine
RAPD primers produced 103 polymorphic bands. Principal component analysis revealed the genomic differentiation
among three Athrotaxis species. Mean genetic distance (mean d) between A. selaginoides D.Don and A. cupressoides
D.Don was 0.89. Mean d values were reduced to 0.42/0.54 between A. laxifolia Hook. and A. selaginoides/A. cupressoides,
respectively. Intraspecific mean d of A. selaginoides and A. cupressoides were, respectively, 0.03 and 0.11. These
values indicated that A. laxifolia, which is regarded as a hybrid between A. selaginoides and A. cupressoides, is genetically
intermediate between A. selaginoides and A. cupressoides. This genetic characteristic and previously reported morphological
characteristics suggest the hybrid origins of A. laxifolia. The genomic composition of A. laxifolia was
estimated by the number of bands specific to A. selaginoides or A. cupressoides in order to determine the genomic contribution
of these two species to its proposed hybrid, A. laxifolia. All of the five individuals investigated herein possessed
genomes derived almost evenly from A. selaginoides and A. cupressoides. Furthermore, the pollen donor of
A. laxifolia was determined by SSCP analysis of the atpAgene on chloroplast DNA. Because all of the five A. laxifolia
possessed the A. selaginoides-type chloroplast genome, A. laxifolia would be a hybrid of A. selaginoides as a paternal
parent and A. cupressoides as a maternal parent.

Item Type:	Article
Authors/Creators:	Isoda, K and Brodribb, TJ and Shiraishi, S
Journal or Publication Title:	Australian Journal of Botany
ISSN:	0067-1924
DOI / ID Number:	10.1071/BT99032
Item Statistics:	View statistics for this item

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