No. IRAs cannot be maintained as joint accounts. One key indicator is the label - IRA stands for individual retirement account. The "individual" in the label suggests that the account must be maintained as an individual account for registration purposes.
Refer also to IRC 408 §, which states that an IRA must be established for an individual. Joint ownership is not allowed under any provisions of the Code or Treasury Regulations.
For further reading, see the Traditional IRAs tutorial.
This question was answered by Denise Appleby