**Qstats** also tests for adherence to Mendelian segregation at all marker loci. For a
given locus, suppose there are genotypic classes. Let be the expected frequency,
and the observed count for the th class. For a sample of size ,
the expected counts will be and the observed frequencies will be .
We can construct a test statistics based on a contigency table

or a comparison of likelihoods

Both and should have a distribution with one degree of freedom for backcrosses and recombinant inbred lines and two degrees of freedom for intercrosses. Both statistics are calculated and presented in a table in the

Christopher Basten 2002-03-27