Fitness Differences among Diploids, Tetraploids, and Their Triploid Progeny in Chamerion angustifolium: Mechanisms of Inviability and Implications for Polyploid Evolution Export

@article{citeulike:4444784, abstract = {Theoretical models indicate that the evolution of tetraploids in diploid populations will depend on both the relative fitness of the tetraploid and that of the diploid-tetraploid hybrids. Hybrids are believed to have lower fitness due to imbalances in either the ploidy (endosperm imbalance) or the ratio of maternal to paternal genomes in their endosperm (genomic imprinting). In this study we created diploids, tetraploids, and hybrid triploids of Chamerion angustifolium from crosses between field-collected diploid and tetraploid plants and evaluated them at six life stages in a greenhouse comparison. Diploid offspring (from 2x x 2x crosses) had significantly higher seed production and lower biomass than tetraploid offspring (from 4x x 4x crosses). Relative to the diploid, the cumulative fitness of tetraploids was 0.67. In general, triploids (from 2x x 4x, 4x x 2x crosses) had significantly lower seed production, lower pollen viability, and higher biomass than diploid individuals. Triploid offspring derived from diploid maternal parents had lower germination rates, but higher pollen production than those with tetraploid mothers. Relative to diploids, the cumulative fitness of 2x x 4x triploids and 4x x 2x triploids was 0.12 and 0.06, respectively, providing some support for effect of differing maternal:paternal ratios and endosperm development as a mechanism of hybrid inviability. Collectively, the data show that tetraploids exhibit an inherent fitness disadvantage, although the partial viability and fertility of triploids may help to reduce the barrier to tetraploid establishment in sympatric populations.}, author = {Burton, Tracy L. and Husband, Brian C.}, citeulike-article-id = {4444784}, citeulike-linkout-0 = {http://dx.doi.org/10.2307/2640616}, citeulike-linkout-1 = {http://www.jstor.org/stable/2640616}, doi = {10.2307/2640616}, issn = {00143820}, journal = {Evolution}, keywords = {crossing\_experiments, fitness, hybridization, polyploidy}, number = {4}, pages = {1182--1191}, posted-at = {2009-04-30 07:33:47}, priority = {2}, publisher = {Society for the Study of Evolution}, title = {Fitness Differences among Diploids, Tetraploids, and Their Triploid Progeny in Chamerion angustifolium: Mechanisms of Inviability and Implications for Polyploid Evolution}, url = {http://dx.doi.org/10.2307/2640616}, volume = {54}, year = {2000} }

TY - JOUR ID - citeulike:4444784 L3 - citeulike-article-id:4444784 N2 - Theoretical models indicate that the evolution of tetraploids in diploid populations will depend on both the relative fitness of the tetraploid and that of the diploid-tetraploid hybrids. Hybrids are believed to have lower fitness due to imbalances in either the ploidy (endosperm imbalance) or the ratio of maternal to paternal genomes in their endosperm (genomic imprinting). In this study we created diploids, tetraploids, and hybrid triploids of Chamerion angustifolium from crosses between field-collected diploid and tetraploid plants and evaluated them at six life stages in a greenhouse comparison. Diploid offspring (from 2x x 2x crosses) had significantly higher seed production and lower biomass than tetraploid offspring (from 4x x 4x crosses). Relative to the diploid, the cumulative fitness of tetraploids was 0.67. In general, triploids (from 2x x 4x, 4x x 2x crosses) had significantly lower seed production, lower pollen viability, and higher biomass than diploid individuals. Triploid offspring derived from diploid maternal parents had lower germination rates, but higher pollen production than those with tetraploid mothers. Relative to diploids, the cumulative fitness of 2x x 4x triploids and 4x x 2x triploids was 0.12 and 0.06, respectively, providing some support for effect of differing maternal:paternal ratios and endosperm development as a mechanism of hybrid inviability. Collectively, the data show that tetraploids exhibit an inherent fitness disadvantage, although the partial viability and fertility of triploids may help to reduce the barrier to tetraploid establishment in sympatric populations. IS - 4 JF - Evolution SN - 00143820 EP - 1191 TI - Fitness Differences among Diploids, Tetraploids, and Their Triploid Progeny in Chamerion angustifolium: Mechanisms of Inviability and Implications for Polyploid Evolution PB - Society for the Study of Evolution VL - 54 SP - 1182 KW - crossing_experiments KW - fitness KW - hybridization KW - polyploidy AU - Burton, Tracy AU - Husband, Brian PY - 2000/// UR - http://dx.doi.org/10.2307/2640616 ER -