Comparative Susceptibility to Amylases of Starch Granules of Several Single Endosperm Mutants and Their Double‐Mutant Combinations with Opaque‐2 in Four Inbred Lines of Maize

The relative susceptibility of starch granules of single mutants and double‐mutant combinations of maize and their normal counterparts to Rhizopus glucoamylase and pancreatin was compared and the relative degradation of starch granules followed by scanning electron microscopy. Starch granules of distinct endosperm mutants were resistant to the action of amylases whilst others showed pin holes on the surface and pores into the inner layers. Starch granules of the sugary, brittle, shrunken, and waxy mutants tended to be digested faster than those of their normal counterparts. The opaque‐2 mutant which improves nutritional quality of endosperm proteins did not change the susceptibility of starch granules to degradation by amylases.