WAXY PROTEIN-DEFICIENCY AND CHROMOSOMAL LOCATION OF CODING GENES IN COMMON WHEAT

Deficiency of the wheat waxy (Wx) proteins (Wx-A1, Wx-B1 and Wx-D1) wa s studied in 1,960 cultivars derived from several countries. Gel elect rophoretic analyses revealed that the null allele for the Wx-A1 protei n occurred frequently in Korean, Japanese and Turkish wheats but was r elatively rare in cultivars from other countries and regions. About 48 % of the wheats deficient for the Wx-B1 protein were from Australia an d India. One Chinese cultivar lacked the Wx-D1 protein. While 9 Japane se cultivars were deficient in both the Wx-A1 and Wx-B1 proteins, no c ultivars lacked both the Wx-A1 and Wx-D1 proteins, both the Wx-B1 and Wx-D1 proteins or all three Wx proteins. Two-dimensional gel electroph oresis revealed polymorphisms of the three Wx proteins that varied acc ording to isoelectric points or molecular weight. The Wx-A1 gene codin g the Wx-A1 protein and the Wx-B1 gene coding the Wx-B1 protein were l ocalized in the distal regions of chromosome arms 7AS and 4AL, respect ively, by deletion mapping using the deletion lines developed in the c ommon wheat cultivar 'Chinese Spring'.