—The genetic correlations are very high. Can you check them?
—Sure
The additive genetic variance for one of the traits was essentially zero, which pushed the correlation to get stuck at 0.99. Looking with more attention at the results of the univariate analyses, showed that the experimental design features (replicates, incomplete blocks) were also close to zero.
A cross tabulation showed that some of the replicates had only a single observation (and many of the incomplete blocks had none), although the families had five observations each.
More importantly, and easier, checking the size of the dataset showed 150 observations. One hundred and fifty observations to estimate the degree of genetic control and associations. Way too small!
The small sample size was not done on purpose; it was just left overs from another project that we are sending for publication soon. Small leftovers, small sample size; enough for a pilot study at the phenotypic level, but not for genetic parameters. There are no miracles in data analysis.