<abstract xmlns="http://www.w3.org/1999/xhtml"><p> Sexual symmetry, defined as equal allelic frequencies among reproduction effective gametes of both sexes, was analysed by means of 10 isozyme loci in three natural populations of Austrocedrus chilensis (dioecious and wind pollinated tree species). Haplotypes of effective gametes were inferred by analysing side-by-side both the embryo and the endosperm of seeds collected from 20 to 27 trees per population. The allelic frequencies of effective ovules and pollen were compared in each of the three populations. The hypothesis of sexual symmetry could only be rejected in case of one locus in two out of three analysed populations. That is, most of the loci surveyed turned out to be symmetric in the three sampled populations in spite of their contrasting environmental conditions. Therefore, sexual symmetry in A. chilensis seems to be mainly uninfluenced by the environment. On the other hand, all loci showed Hardy- Weinberg (HW) proportions in the three populations, even those that resulted asymmetric. HW structure is usually considered as enough evidence of panmixia, what implies sexual symmetry, and consequently this result gives an example of the low reliability of indirect methods of testing genetic processes, such as the classical HW test.</p></abstract>

Sexual symmetry, defined as equal allelic frequencies among reproduction effective gametes of both sexes, was analysed by means of 10 isozyme loci in three natural populations of Austrocedrus chilensis (dioecious and wind pollinated tree species). Haplotypes of effective gametes were inferred by analysing side-by-side both the embryo and the endosperm of seeds collected from 20 to 27 trees per population. The allelic frequencies of effective ovules and pollen were compared in each of the three populations. The hypothesis of sexual symmetry could only be rejected in case of one locus in two out of three analysed populations. That is, most of the loci surveyed turned out to be symmetric in the three sampled populations in spite of their contrasting environmental conditions. Therefore, sexual symmetry in A. chilensis seems to be mainly uninfluenced by the environment. On the other hand, all loci showed Hardy- Weinberg (HW) proportions in the three populations, even those that resulted asymmetric. HW structure is usually considered as enough evidence of panmixia, what implies sexual symmetry, and consequently this result gives an example of the low reliability of indirect methods of testing genetic processes, such as the classical HW test.

Sexual Symmetry in Natural Populations of the Patagonian Cypress (Austrocedrus chilensis)

Silvae Genetica

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Sexual symmetry, defined as equal allelic frequencies among reproduction effective gametes of both sexes, was analysed by means of 10 isozyme loci in three...

Sexual Symmetry in Natural Populations of the Patagonian Cypress (Austrocedrus chilensis)

Publié en ligne: 27 oct. 2017

Pages: 244 - 246

Reçu: 02 août 2004

DOI: https://doi.org/10.1515/sg-2004-0044

Mots clés
reproductive system, Austrocedrus, isozymes, Cupressaceae

© 2017

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Sexual Symmetry in Natural Populations of the Patagonian Cypress (Austrocedrus chilensis)

Publié en ligne: 27 oct. 2017

Pages: 244 - 246

Reçu: 02 août 2004

DOI: https://doi.org/10.1515/sg-2004-0044

Mots clésreproductive system, Austrocedrus, isozymes, Cupressaceae

© 2017

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Mots clés
reproductive system, Austrocedrus, isozymes, Cupressaceae