GENETIC-VARIATION IN CENTRAL AND DISJUNCT POPULATIONS OF LILIUM-PARRYI

We compared levels of genetic variability in small, isolated populatio ns of Lilium parryi in Arizona with those found in large populations i n California. Arizona populations were presumably derived from Califor nia populations; they were significantly less variable and showed evid ence of much higher levels of inbreeding. One California locality whos e population structure is similar to those found in Arizona also had r elatively low levels of genetic variability. However, the other Califo rnia populations were highly variable and showed lower levels of inbre eding than Arizona populations. There was significant genetic differen tiation among all populations. In Arizona, there was no relationship b etween current population size and genetic variability. Arizona popula tions may be vulnerable to extinction, given the magnitude of environm ental modifications in their habitats, their small sizes, and their lo w levels of variability.