Light micrographs and seeds growth of F3 populations resulting from crosses between dwarf wild type (JI 2822) and dwarf mutant pea (JI 3020). (a-l) Light micrographs of segregant F3 sections. (a-d) Heterozygote genotype Def/def (+-) line 77. a Young seed of line 77 shows a less differentiated palisade layer. b Mature seed section of line 77 shows normal double palisade layer development. c-d Higher magnification of (a) and (b), respectively. (e-h) Homozygous dominant genotype Def/Def (++) line 1. e Young seed section of line 1. f Mature seed section of line 1. g-h Higher magnification of (e) and (f), respectively. i-l Homozygous recessive genotype line 33. (i) Young seed section of line 33 shows no distinct palisade layer. (j) Mature seed section of line 33. (k)-(l) Higher magnification of (i) and (j), respectively. (m) Relationship between seed fresh weight and pod age in F3 plants. AZ Abscission zone, CPL Counterpalisade layer, PL Palisade layer. Bars = 12.5 μm (a, b, e, f, i, and j); 25 μm (c, d, g, h, k, and l).