SPATIAL GENETIC STRUCTURE IN POPULATIONS OF HOSTA CAPITATA AND HOSTA MINOR (LILIACEAE)

Abstract

The spatial distribution of genotypes was examined in each of two populations of Hosta capitata and H. minor using spatial autocorrelation analysis of enzyme polymorphisms. Although these two species have a similar life history and similar ecological traits, this study indicates that the pattern of spatial genetic distribution in the species differed. The percentage of significant Moran's I for all distance classes differs (20% and 14% in H. capitata; 33% and 53% in H. minor). Significant positive Moran's I values were detected in the shorter distance classes for H. capitata (distance class 1–3, 0–4.5 m), whereas these values for H. minor were observed in longer distance classes (distance classes 5–6, 0–10.4 m). Approximate minimum patch area for H, capitata (7–20 m2) is smaller than that of H. minor (38–78 m2). As the weights of seeds are nearly the same in both species and seedlings grow near maternal individuals in both species, and gene flow via seed is expected to be at the same level, the observed difference in patterns of spatial genetic distribution may in part be due to the differences between both species in terms of the extent of gene flow via pollen dispersal, selective forces, and other unknown factors of their reproductive biology.