Final answer:
In a Southern blot procedure with excessively high stringency, the autoradiogram may display weak or no signals due to the DNA probe binding only to perfectly complementary sequences, leading to missed hybridization with the target.
Step-by-step explanation:
If the stringency was too high during the Southern blot procedure, the autoradiogram would likely show a reduced number or even the complete absence of hybridization signals. High stringency conditions can cause the DNA probe to bind only to DNA sequences with a very high level of complementarity. If the stringency is too high, this can prevent the probe from binding to its target sequence if there are any mismatches present, leading to a weak signal or no signal at all on the autoradiogram.