An Analysis of Seed Development in Pisum sativum XVII. The Effect of the rb Locus Alone and in Combination with r on the Growth and Development of the Seed

Near-isogenic lines have been produced in pea to examine the effects of genes at the r and rb loci on the growth and development of the seed. The rb alleles were found to have an effect on the growth of the testa as well as on that of the embryo in contrast to those at the r locus which only affect the latter. The relationship between the fresh and dry weights of the embryos of rb isoline and the double mutant differed from that of the round-seeded wild-type line. Furthermore, for this relationship, the double mutant line very closely resembled the rr isoline.