3 



interpretation of banding patterns (Table 3). All loci were 

 monomorphic except for phosphoglucose isomerase, locus 2 

 ( Pqi-2 ) . Arabis fecunda expressed two alleles (slow=100 and 

 fast=167) at Pqi-2 . Jerry Creek and Lime Gulch populations 

 were fixed for the slow allele (100) . All other populations 

 were polymorphic with both alleles present in homozygote and 

 heterozygote plants. Progeny analyses have not been done, 

 but banding patterns are similar to other plants (Gottlieb 

 1977 and 1981, Crawford and Wilson 1979, Adams and Allard 

 1977, and Loukas et al. 1983). PGI is a highly polymorphic, 

 dimeric enzyme system in plants. Most plants have two to 

 three isozymes in the chloroplast and cytosol. Pgi-1 is 

 reported as monomorphic in most plants. Arabis fecunda had 

 a very faint band at PGI-1. The faint expression of PGI-1 

 is possibly due to incomplete disruption of chloroplasts. 

 Allozyme banding patterns suggest that these populations of 

 Arabis fecunda exhibit disomic inheritance. 



Genetic Variation 



Summary statistics . The mean number of alleles per 

 locus for the six A^. fecunda populations is 1.06 alleles per 

 locus. Mean heterozygosity 0.006. The percentage of 

 polymorphic loci is 3.7%. Genetic distances were not 

 calculated, since estimates based on a single polymorphic 

 locus would have no biological meaning. 



