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Title: Genetic structure and immigation in French sea beet

item Panella, Leonard
item Richards, Christopher
item Fenwick, Ann
item Reeves, Patrick

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 2/15/2013
Publication Date: 2/27/2013
Citation: Panella, L.W., Richards, C.M., Fenwick, A.L., Reeves, P.A. 2013. Genetic structure and immigation in French sea beet. Meeting Abstract. ASSBT Meetings, Anaheim, CA. 02/27/2013.

Interpretive Summary:

Technical Abstract: In this study we examined accessions of sea beet (Beta vulgaris subsp. maritima (L.) Arcang.), collected along the Mediterranean Sea up the Atlantic coast of France. The aim was to identify the scale and magnitude of differentiation and diversity in these accessions using both molecular and quantitative traits. Data filtering (limit missing data to only one locus per multilocus genotype) reduced the final sample size from 336 (12 individuals each for 28 accessions) to 277 individuals. With SSR data, the observed heterozygosity was high across the accessions (mean 0.48), the mean inbreeding coefficient was fairly high (0.13) and significantly above zero. Inbreeding increased northward and heterozygosity increased southward. The mode value for K (number of genetic clusters) was found to be 2 for the entire data set. Phenotypic foliar traits were significantly different among accessions in one way ANOVA. Leaf length/width ratio, petiole length/width ratio and leaf thickness were significant at the 0.001, 0.05 and 0.001 levels respectively. Combining all three traits into a multivariate discriminant analysis using group assignments of K=2, resulted in a statistically significant discriminant function that could correctly predict group membership 75% of the time. Migration rate was estimated among the three classes of genotypes (Mediterranean, Atlantic and Atlantic immigrant) using a Bayesian estimator. The rates of migration were quite low between the Mediterranean and Atlantic groups in both directions. The rate of migration from the Mediterranean group to the putative Atlantic immigrant group was 20 times higher than from the Mediterranean group to the Atlantic group. The migration between the Atlantic and the Atlantic immigrant group was four higher from the Atlantic immigrant group to the Atlantic group than the reverse.