Using associations between at least one nucleic sequence polymorphism Sh2 gene and at least one of the seed quality characteristic, in methods of selecting plants

The invention relates to the use of a probe or a nucleotide primer in a method of selecting plants having improved phenotypic seed quality characteristics for the detection of a polymorphic base or a polymorphic nucleotide sequence that defines an allele of a polymorphic site of the Sh2 gene of sequence SEQ ID N DEG 1. Said polymorphic base or said polymorphic nucleotide sequence is contained in a nucleic acid included in an Sh2 gene. The invention can be used to obtain transformed plants that can produce seeds having improved agri-food or industrial qualities.