We do not have the original manuscript here; the printer’s manuscript reads bore, which has been maintained in all the printed editions. It is possible that the original text read bare here and this past-tense form was miswritten as the modern past-tense form bore. In the earliest textual sources, nearly all the past-tense forms for the verb bear read bare rather than bore. But here in Alma 1:25, the earliest extant source reads bore. Since bore is possible, the critical text will maintain it in this instance, even though it could be an error for bare. Such an error in transmission apparently occurred in 1 Nephi 11:7 (see the discussion for that verse). Another example of possible original bore is in Alma 53:13 (see the discussion there as well).
We find a similar situation for the past tense of swear in the Book of Mormon text: a mixture of the archaic sware and the more modern swore in the earliest textual sources, with a tendency in the history of the text to replace sware with swore. For discussion, see under Enos 1:14. For a general discussion of the variation involving bare /bore and sware /swore, see under past tense in volume 3.
Summary: Maintain in Alma 1:25 the use of bore as the past tense of the verb bear; here the earliest textual source, the printer’s manuscript, reads bore; the modern form bore may be a mistake for bare, but it is nonetheless possible.