Spatial autocorrelation of allozyme and quantitative markers within a natural population of Centaurea jacea (Asteraceae)

This paper compares the fine-scale genetic structure of quantitative traits and allozyme markers within a natural population of Centaurea jacea s.l. T o that end, a spatial autocorrelation approach is developed based on pairwi se correlation coefficients between individuals and using sib families. Sta tistical properties of the proposed statistics are investigated with numeri cal simulations. Our results show that most quantitative traits have a sign ificant spatial structure for their genetic component. On average, allozyme markers and the genetic component of quantitative traits have similar patt erns of spatial autocorrelation that are consistent with a neutral model of isolation by distance. We also show evidence that environmental heterogene ity generates a spatial structure for the environmental component of quanti tative traits. Results are discussed in terms of mechanisms generating spat ial structure and are compared with those obtained on a large geographical scale.