Waxy Endosperm Mutants of Bread Wheat (Triticum aestivum L.) and Their Starch Properties

Abstract

Two waxy bread wheat lines, K107Wxl and K107Wx2, have been developed by treating cv. Kanto 107 seeds with ethyl mcthancsulphonate (EMS). About 2,000 seeds of the cultivar were soaked for 4 hours in 0.5% EMS dissolved in 7% ethanol, and then 2,000 seeds were sown in a greenhouse and 10,634 M2 seeds were obtained from 1,872 M1 plants. Cross sections of the distal endosperms of 4,000 M2 seeds were stained with an iodine-potassium iodide solution, and two seeds stained red-brown. Since the M3 and M4 seeds derived from the remaining proximal halves of these two seeds showed the characteristic feature of waxy endosperm, the waxy endosperm character was considered to be genetically fixed in these two mutant lines, which were designated as K107Wxl and K107Wx2. The amylose content of endosperm starch from both mutant lines was 0.9%, and no waxy proteins were detected in the starch of either line. The agronomic characters of K107Wxl and K107Wx2 were very similar to those of cv. Kanto 107 grown under field conditions, except for the heading dates of the mutant lines and the 1,000-grain weight of K107Wx2. These results indicate that the mutagen treatment of seeds is effective in inducing of waxy, i.e. amylose-free, mutants when a bread wheat cultivar has a single waxy protein in their endosperm starch.