Electrophoresis of beta-amylase enzymes was carried out in polyacrilamide gel with tris-glycine buffer (pH 8.3) as published previously by Netsvetaev (1992). Reducing agents increased beta-amylase activity from matured seeds and not considerably influenced on beta-amylase of germinated seed. Amongst of 189 progenies F-->00 Maja × Viner cross (var. Krasnoufimsky 9S), no recombinants combining non-parental beta-amylase isozymes at various stages of seed development were found.
Locus Bmyl or tightly linked loci coding for ,beta-amylase isozymes in matured and germinated barley seeds were studied with respect to chromosome location. Analysis of wheat-barley additional stocks confirmed location of, beta-amylase locus is on barley chromosome 4 as was showed earlier by Powling et al. (1981).
The position of locus Bmy1 was calculated using recombination values between the genes ml-o (resistance to Erysiphe graminis hordei from MC 20), and f9(chlorina 9), from the cross ml-o+f9 × Cristal and the genes ml-o (resistance to Erysiphe graminis hordei from M66), Ke (elevated hooded), and gl2 (glossy leaf 2) from the cross M66 × Ke+g12. Varieties Cristal and M66 had beta-amylase allele Bmy1Ar but other parental lines carried Bmy1Br. Results are presented in Tables 1 and 2.
These data do not oppose with findings of Nielsen et al. (1983). Figure 1 gives presumable five-gene map for chromosome 4.
Third allele named as BmylAI was found in varieties Algerian (CI 1179), Asse. Irnula, and Zenit (KM 123).
Netsvetaev, V. P. 1992. Location of ,beta-amylase coding locus (Bmy 1) on barley chromosome 4. Cytology and Genetics (Kiev) (In press).
Nielsen, G., H. Johansen, and J. Jensen. 1983. Localization on barley chromosome 4 of
genes coding for ,beta-amylase (Bmyl) and protein 2 (Paz 1). BGN 13:55-56.
Powling, A., A. K. M. R. Islam, and K. W. Shepherd. 1981. Isozymes in wheat-barley hybrid derivative lines. Biochem. Genet. 19:237-253.