fptest: a sas routine for testing differences in allelic count.

Allelic count is an important measure of genetic diversity, but it is a function of sample size. This size-dependent property may not only introduce bias in its estimation, but also cause difficulty in testing the significance of its difference between samples. Here we present a sas routine of random permutation that can assist in the assessment of allelic count differences among groups of variable size. An example is given to examine the statistical significance of the differences in allelic count among eight breeding periods of Canadian oat cultivars.