Chain Length Distribution of Amylopectins of Several Single Mutants and the Normal Counterpart, and Sugary‐1 Phytoglycogen in Maize ( Zea mays L.)

β‐Limit dextrins of starches of normal (nonmutant), amylose‐extender ( ae ), dull ( du ), sugary‐2 ( su 2 ) and waxy ( wx ) maize, and phytoglycogen of sugar‐1 (su 1 ) maize were prepared. The β‐limit dextrins were successively debranched by isoamylase and pullulanase, and followed by quantitative gel‐filtration. The ratio of A to B chains for the ae starch appeared to be high and that for su 1 phytoglycogen was low. The ratio of short B to long B chains for the du starch was high and that for the ae starch appeared to be low. The phytoglycogen did not contain long B chains. The unit chain‐length distribution of amylopectins of the normal, wx , and su 2 starches were similar. Fine structures of maize amylopectins and su 1 phytoglycogen were modeled and described.