4VariacionEvolucion2b copy.pdf - Instituto de Ecología

polymorphic loci and number of polymorphic alleles, and forfour genetic parameters: population differentiation measuredwith F STand R ST, and mean within-population diversity measuredas H Eand H OTable 2 Database of the review on life history traits and STMSmarker-based methods, diversity. indicating Number that of type studies, of marker mean isand standard deviationof are relatively given for little each importance of five sampling (Table 1). strategy A sur-parameters: numberprobablyprisingly of large populations, discrepancy number between of Φ plants per population, maximumSTand G STis notedfor RAPD- geographical and AFLP-based distance studies. between However, sampled analysis populations, number ofof onlypolymorphicthose 15 RAPD-basedloci andstudiesnumberthatofreportpolymorphicbothalleles, and forfour genetic parameters: population differentiation measuredparameters, results in 0.24 (Φwith F STand R ST, and ST) and 0.21 (Gmean within-population ST), while thediversity measuredeight AFLP studies that similarly report both parameters,as H Eand H OFor STMS-based studies, F STwas negativelywith both H E(r = −0.782, d.f. = 31, P < 0.01) an−0.853, d.f. = 22, P < 0.01), whereas the associatioing R STwere considerably weaker (H E, r = −0.459ns; H O, r = −0.584, d.f. = 14, P < 0.05).Microsatélites, Nybom, 2004!Parameter N Mean ± SDPopulations 106 4.1 ± 6.1Plants 104 51.5 ± 55.4Distance (km) 37 1103 ± 2694Loci 105 8.4 ± 6.7Alleles 90 83.2 ± 63.0F ST33 0.26 ± 0.17R ST18 0.24 ± 0.21H E104 0.61 ± 0.21H O80 0.58 ± 0.22Effects of sampling strategies on genetic parameWhen the RAPD-derived population genetmeters were evaluated for their association withstrategies, only three significant regression equaobtained. Somewhat surprisingly, number of ppopulation had a significant, positive effect on12.43, DNA-MARKERS d.f. = 1/41, P = 0.001) although AND not PLA on Φ SMore expected was the strong positive effect ofcollection distance on hand. both Φ ST Correspond(F = 9.10, d.P = 0.003) and G ST(F = 14.68, yielded d.f. = similar 1/41, P < resu 0.00AFLP data, the only significant P < 0.05) regression and for was H pfor maximum collection The distance ISSR and data H pop set , how wbecame nonsignificant when For a single STMS-based outlier wasfrom the analysis.with both H E(r = −For the STMS data, number of investigated po−0.853, d.f. = 22, P