Mainly U.S.: recent coinage, combining the short form Jo with the productive suffix -lene, extracted from names such as Marlene. It seems to have originated in the United States in the 1940s. It was made famous by a hit song with this title, recorded by Dolly Parton in 1979.
English and Scottish: from Maurice, an Old French personal name introduced to Britain by the Normans, Latin Mauritius, a derivative of Maurus (see Moore). This was the name of several early Christian saints. In some cases it may be a nickname of the same derivation for someone with a swarthy complexion.