Did you read the instructions? Its clearly mentioned that you should have joint account for proof of funds only with spouse.
http://www.saskatchewan.ca/residents/moving-to-saskatchewan/immigrating-to-saskatchewan/saskatchewan-immigrant-nominee-program/applicants-international-skilled-workers/international-skilled-worker-saskatchewan-express-entry/required-documents-for-saskatchewan-express-entry
canada_aspirant_15 said:
Yes, it's valid. Remember to maintain POF for min 3 months before the Application sent.