WAXY ENDOSPERM MUTANTS OF BREAD WHEAT (TRITICUM-AESTIVUM L) AND THEIRSTARCH PROPERTIES

Two waxy bread wheat lines, K107Wx1 and K107Wx2, have been developed b y treating cv. Kanto 107 seeds with ethyl methanesulphonate (EMS), Abo ut 2,000 seeds of the cultivar were soaked for 4 hours in 0.5% EMS dis solved in 7% ethanol, and then 2,000 seeds were sown in a greenhouse a nd 10,634 M-2 seeds were obtained from 1,872 M-1 plants, Cross section s of the distal endosperms of 4,000 M-2 seeds were stained with an iod ine-potassium iodide solution, and two seeds stained red-brown, Since the M-3 and M-4 seeds derived from the remaining proximal halves of th ese tn a seeds showed the characteristic feature of waxy endosperm, th e waxy endosperm character was considered to be genetically fixed in t hese two mutant lines, which were designated as K107Wx1 and K107Wx2, T he 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 K107Wx1 and K107Wx2 were very similar to thos e of cv. Kanto 107 grown under field conditions, except for the headin g dates of the mutant lines and the 1,000-grain weight of K107Wx2. The se results indicate that the mutagen treatment of seeds is effective i n inducing of waxy, i.e. amylose-free, mutants when a bread wheat cult ivar has a single waxy protein in their endosperm starch.