Variation of starch granules in diploid species of the genus Avena L.

Composite starch granules, the main product of assimilation in oat endosperm, were analyzed in the accessions of both wild and cultivated diploid species of the genus Avena. Simple starch granules are mostly synthesized in the outer parts of the endosperm tissue. The size of sub-grains in a composite granule does not depend on a wild or cultivated status of the species. Inter-specific variation in the size differences of composite granules is large. Also, a broad variation has been detected for granules analyzed in a Lugol’s solution or polarizing light. This analysis revealed a difference between the synthesis of amylopectin versus amylose in a granule. Examples of occurrences of low levels of amylopectin synthesis are provided.