Spatial genetic structure of Allozyme polymorphisms in a population of Eurya japonica (Theaceae)

Eurya japonica THUNB. (Theaceae), a dioecious, insect-pollinated, blood-lea ved evergreen tree, is widely distributed in East Asia. We used allozyme lo ci to examine the temporal and spatial distribution of genetic variation in the study population which was contained in a 60-m X 100-m area. The popul ation had high levels of allozyme variation, but mean expected heterozygosi ty differed among three size classes: 0.277 for seedlings and 2-yrs old juv eniles; 0.310 for juveniles; and 0.337 for adults. Differences in allelic f requencies among the size classes were significant for foul out of eight lo ci. In addition, the population was spatially structured: values of Moran's I-statistics were statistically significant in 65 (23.2%) of 280 cases for the Entire population. There is substantial genetic similarity among indiv iduals separated by less than 30 m distances, and this degree of similarity is consistent with the pollination system and seed dispersal mechanism. Th e results reveal that genetic diversity within a local population of E. jap onica is not uniform in time and space.