Ayn Rand made two lists of virtues, one published in The Virtue of Selfishness, the other unpublished in her Journal, in a section called, "The Moral Basis Of Individualism."
The published list of virtues includes: Reason, Purpose, Self-Esteem, Rationality, Productiveness, and Pride.
The unpublished list of virtues includes: Integrity [which Rand described as, "the first, greatest and noblest of all virtues"], Courage, Honesty, Honor, Self-confidence, Strength, Justice, Wisdom, and Self-respect.
The following links pertain to the moral source of virtues. The first directly addresses your question:
Integrity: The Virtues Of The Moral Individual
Principles
Ethical Principles
Ayn Rand's Ethics
Objective Ethics for Freedom and Happiness (The Is/Ought Fallacy)