Scribe 2 of 𝓟 wrote “partakers of the spirit”, an obvious error given that the following words are “of the tree of life”. Oliver Cowdery, when he proofed 𝓟 against 𝓞, replaced spirit with fruit, the undoubted reading in 𝓞. Note that there is some visual similarity between the two words fruit and spirit. Perhaps scribe 2 expected “partakers of the spirit”, yet elsewhere the Book of Mormon text refers only to “partaking of fruit” (23 times), never to “partaking of the spirit”.
Summary: Accept in Alma 5:62 Oliver Cowdery’s correction of spirit to fruit, which is obviously the appropriate reading for the following “of the tree of life”.