Relationship between heterosis and parental genetic distance based on RAPD and EST-SSR markers in Pinus taeda L. × P. caribaea Morelet

摘要

The assessment of parental genetic distances (GDs) and their correlations with progeny performancehave largely been circumvented by DNA marker development. Both strong and weak correlations betweenprogeny performance and parental GDs have been detected in numerous plant species. ESTs (expressedsequence tags) in the pine genome can be functionally annotated, providing ideal makers to explain heteroticeffects. We found stronger correlations between F1 hybrid performance and their parental GDs based on 4EST-simple sequence repeat (SSR) primer pairs with 19 alleles compared to random amplified polymorphicDNA (RAPD) primers with 46 bands. The correlation coefficients of parental GDs based on EST-SSR and/orRAPDs with the better parental heterosis (BPH) of seedling diameter at ground line (DGL) were 0.288 (p =0.049) and 0.290 (p = 0.050), respectively. In contrast, there was no significant correlation between parentalGDs based on RAPD markers and F1 hybrid growth traits. Our results demonstrate that appropriate molecularmarkers more effectively illustrated heterotic effects than randomized markers. We expect that functionalgene markers from sequenced genomes will provide a starting point for heterosis research in pines.