POLYMORPHISM OF WAXY PROTEINS IN IBERIAN HEXAPLOID WHEATS

A collection of 130 cultivars of bread wheat, 332 landraces of bread w heat and 144 spelt wheats was analysed for waxy proteins in the grain. The electrophoretic patterns showed very low polymorphism and most of the hexaploid wheats had the Wx-A1a, Wx-D1a and Wx-B1a alleles of 'Ch inese Spring'. Two alleles were detected at Wx-A1 (Wx-A1a, and Wx-A1b (null)), the latter was present in only 5.1% of the bread wheat landra ces and 7.6% of the spelt wheats. No allelic variation was found at th e Wx-D1 locus and all the hexaploid wheats had the Ws-D1a allele. Wx-B 1 was the most polymorphic locus, with three alleles detected: Wx-B1a, Wx-B1b (null) and Wx-B1c' coding for a Wx-B1 protein with a slightly different mobility from Wx-B1a. The null Wx-B1b allele was found in 10 .8% of the bread wheat cultivars, 21.4% of the bread wheat landraces a nd 12.5% of the spelt wheats. Among the 604 hexaploid wheats analysed, only two bread wheal landraces (0.6%) and two spelt wheats (1.4%) had the null allele at both Wx-A1 and Wx-B1 loci.