Pisum sativum seed globulins as biochemical markers for « wrinkled - smooth » seed character : comparison of genotypes through different protein extraction and electrophoretic procedures Rosa RAO

ter, Genetic markers, Electrophoresis. Nine cultivars representing four genotype classes involving two genes ra and rb which are implicated in the smooth-wrinkled character of seeds and in the simple-compound character of starch granules, have been investigated through storage protein electrophoretic patterns. Proteins were alternatively extracted from flours and from protein bodies which were obtained either from cotyledons or from seed flours. Vicilin and legumin fractions were isolated from globulins originating from different sources. Their amino acid compositions were analyzed and the legumin-vicilin ratios were calculated. Sodium dodecyl sulfate polyacrylamide (homogeneous or gradient) gel electrophoresis was used to reveal the heterogeneity of the fractions. If the electrophoregrams of protein body crude extract allowed cultivar comparison, only purified vicilin ones could be interpreted in order to classify the cultivars in groups corresponding to the different genotypes. Comparing the vicilin patterns of the four genotypes, correlation between wrinkled phenotypes and presence of a 60 kD vicilin band is evidenced. As for cereal mutants, the genes involved in the polysaccharide synthesis influence only slightly the storage protein patterns but greatly the relative amount of globulin fractions. It is concluded that the two considered genes ra and rb are involved in storage protein synthesis.