Chromosome Constitution of Hexaploid Triticale Lines in the Recent International Yield Trials*

Lines of hexaploid triticale included in the 11th and 12th Eucarpia Triticale Yield Nurseries and the 18th and 19th International Triticale Yield Nurseries were karyotyped using C-banding. A new chromosome substitution, 6D(6A), was identified in both spring and winter triticales. It is likely that the substitution first appeared in the progenies of octoploid × hexaploid triticale hybrids at CIMMYT and within a few years spread to about one-fourth of spring materials. The 2D(2R) substitution appeared in winter triticales, probably by introgression from spring lines from CIMMYT.     

Transfer of the Glu-D1 Gene from Chromosome 1D to Chromosome 1A in Hexaploid Triticale

To complement previously developed recombinant chromosomes 1R.1D, two series of translocations involving the Glu-D1 gene from chromosome ID to chromosome 1A were produced in hexaploid triticale. These series involve seven independent transfers of allele d encoding for high molecular weight glutenin subunits 5+10 and ten independent transfers involving allele a encoding for HMW glutenin subunits 2 + 12. The frequency of homoeologous recombination between chromosomes 1A and 1D was within the range observed for pairs of homologues in wheat, supporting earlier observations that homoeologous recombination in triticale is frequent. Recombined chromosomes 1A.1D can be used to introduce the Glu-D1 gene to durum wheats, and to manipulate the dosage of Glu-D1 in hexaploid triticale and bread wheat.     

六倍体小黑麦基于农艺性状和品质性状的多样性分析

为明确从国际玉米小麦改良中心(CIMMYT)引进的111份六倍体小黑麦的遗传多样性特点,为其有效利用提供参考依据,对其农艺性状和品质性状特点进行了多样性分析。结果表明：6个农艺性状的平均变异系数为16.94%,平均多样性指数是1.96,小穗数/穗、穗长和千粒重的多样性指数均高于2.00;10个品质性状的平均变异系数为8.60%,平均多样性指数是1.94,吸水率、面团稳定时间的多样性指数均高于2.00。结论：111份六倍体小黑麦的农艺性状和品质性状表现出较大的差异,具有较丰富的多样性。     

The effect of introgressions of wheat D-genome chromosomes into 'Presto' triticale

Hexaploid triticale (X Triticosecale Wittmack) (2n= 6x= 42, AABBRR) and wheat (Triticum aestivum L.) (2n= 6x= 42, AABBDD) differ in their R and D-genomes. This produces differences in both agronomic and end-use quality characteristics. Our objective was to determine how introgressions of individual chromosomes from the D-genome of wheat affect these characteristics of a winter triticale 'Presto'. We studied the effects of 18 D-genome chromosome substitution lines, 15 sib-lines as controls, and five check cultivars at Lincoln, NE in 1996, using a randomized complete block design with two replications. The experiment was repeated at Lincoln and Mead, NE in 1997 and 1998 with 15 substitution lines that survived the first winter in Lincoln, along with their 12 control sibs and five check cultivars. Few D-genome chromosomes had positive effects. Chromosomes 2D, 4D, and 6D significantly reduced plant height when substituted for 2R, 4B, and 6R, respectively. No grain yield increases were associated with any of the D-genome chromosomes tested, but three substitutions decreased the grain yield. Depending on the allele of the hardness gene present, chromosome 5D increased or decreased kernel hardness when substituted for 5R or 5A, respectively. Introgressions of chromosomes 1D and 6D improved end-use quality characteristics of Presto. These results suggest that apart from beneficial effects of individual loci located on the D-genome chromosomes, no major benefit can be expected from D-genome chromosome substitutions.     

直接导入农林10号矮秆基因于八倍体小黑麦的研究

用杂交、回交方法,将农林10号的矮秆基因导入八倍体小黑麦Y1139F_7中。和预期的一样,在不涉及R组染色体重组的情况下,导入后的八倍体小黑麦种子饱满度并未下降,还略有提高。这是利用直接导入法导入普通小麦有利基因于八倍体小黑麦的第一个实例.为“未经改良的R组染色体对八倍体小黑麦的种子饱满度有干扰作用”提供了间接的证据。     

SDS-PAGE of the high-molecular-weight subunits of wheat glutenin and the characterization of 1R (1B) substitution and 1BL/1RS translocation lines

Summary The high-molecular-weight subunits of glutenin from wheat 1R(1B) substitution and 1BL/1RS translocation lines were fractionated by SDS-PAGE. Two new subunits denoted R₁ and R₂ were characterized in 1R(1B) substitution, but not in 1BL/1RS translocation lines. R₁ and R₂ were proved to be rye proteins by 2d electrophoresis (NEPHGE x SDS-PAGE).In contrast to literature citations it was demonstrated that the cultivar Winnetou is a 1R(1B) substitution line and the cultivars Clement and Mildress both are 1BL/1RS translocation lines.     

Kernel hardness and baking quality of wheat — A genetic analysis using chromosome substitution lines

Summary An attempt was made to identify the chromosomal location of genetic control of a few components of wheat quality, using chromosome substitution lines of Cappelle Desprez, Cheyenne, Hope, and Timstein into the recipient variety Chinese Spring.Major factors for kernel hardness and increased baking absorption were found on chromosomes 5D of Cheyenne and Hope, and on 3B, 5D and 7D of Timstein. In Timstein, the presence of one of these chromosomes sufficed to make the wheat kernels hard.Factors for favourable dough properties were identified on a few other chromosomes, different in various varieties. These were 1A of Cappelle Desprez and Cheyenne, 3B of Hope, and 2D of Timstein. All but one of these chromosomes showed an increase in loaf volume to a level in-between those of the recipient variety Chinese Spring and the donor varieties. No relationship was found between kernel hardness and dough-making and baking properties.It was assumed that wheat quality is due to a combination of kernel hardness and favourable dough-making properties. As the genes for these factors are located on different chromosomes, it should not be too difficult to introduce both factors in existing varieties with poor baking properties. In a wheat breeding programme, the quality of new lines can be assessed in a rather simple way by determining kernel hardness and dough stability.