Agronomy and Horticulture Department


Date of this Version



Published in Plant Breeding 128, 70—73 (2009)


The entire USDA-ARS maintained collection of 650 accessions of proso millet (Panicum miliaceum L.) was evaluated for the presence of accessions with waxy (amylose-free) endosperm starch. Six accessions, five of which derived from mainland China, were identified. Segregation ratios for waxy endosperm were evaluated in F2 and F3 populations derived from crosses between two waxy accessions, PI 436625 (Lung Shu 16) and PI 436626 (Lung Shu 18), and several wildtype accessions. The waxy trait was found to be under the control of duplicate recessive alleles at two loci, herein designated wx-1 and wx-2. Wild-type alleles at these loci were designated Wx-1 and Wx-2. Iodine-binding revealed a mean grain-starch amylose concentration of 3.5% in waxy lines and 25.3% in wild-type proso. Expression of the granulebound starch synthase (waxy protein) in waxy lines was reduced to approximately one-tenth that of wild-type accessions. The waxy accessions identified now are available for the introgression of this trait into breeding lines adapted to the Great Plains of North America