Relatedness measured by oligonucleotide probe DNA fingerprints and an estimate of the mating system of Sea Lavender (Limonium carolinianum)

Abstract

Using DNA fingerprint markers within species and populations of wild plants requires information on the relationship between fingerprint similarity and relatedness. We identified a hypervariable marker based on oliog(GATA)₄-hybridization of DpnII-cut genomic DNA from Sea Lavender (Limonium carolinianum). Banding patterns were somatically stable and highly variable among unrelated individuals. Band molecular-weight sizing errors (as a percent of band molecular weight) were estimated at 0.44%±0.003 within gels and 0.76%±0.964 between gels. Band sizing errors defined a 99% confidence bin of ±0.95% (1.90% total) of molecular weight. Band-sharing estimates were based on this bin size and on variance estimates that compensate for non-independent comparisons. Band-sharing among nine unrelated individuals (θ) was 0.198±0.O11. Experimental pollinations designed to produce selfed, fulland half-sib progeny groups led to five selfed progeny groups and no outcrossed progeny (mean band-sharing, ovS=0.468±0.074). A linear regression between band-sharing (S) and relatedness (r) assuming 17% inbreeding was r=0.006+0.914*S (R²=0.973) and established the maximum amount of inbreeding. ovS(0.392±0.022) estimated from wild pollinated seeds from four maternal families was intermediate to unrelated individuals and experimental selfed progeny, giving evidence for mixed mating in wild plants. More extensive plant pedigrees with known levels of inbreeding will be needed to measure variation in the relationship between S and r among populations and families.