A series of independent non-transgenic mutations found in the fruit PG gene of tomato; tomato plants having these mutations in their fruit PG gene; and a method of creating and identifying similar and/or additional mutations in the PG gene by screening pooled and/or individual tomato plants. The tomato plants of the present invention exhibit reduced PG enzyme activity and fruit that soften more slowly post harvest without having the inclusion of foreign nucleic acids in their genomes.