Triticale (×Triticosecale Wittmack) is the intergeneric hybrid between the female parent wheat (Triticum ssp.) and the male parent rye (Secale ssp.). The early work identifying and then producing primary and secondary triticales is described. Early wheat–rye hybrids were characterized by reproductive disorders and the cytology and meiotic characteristics have received much attention. Chromosome constitution has been studied particularly in relation to R-D substitution. Triticale has always been bred as a self-pollinating crop, although outcrossing can occur, and current cultivars are all nearly homozygous and homogeneous lines. Hybrid breeding (using cytoplasmic male sterility) makes the optimum exploitation of heterosis possible and, with the aid of molecular markers, triticale germplasm is presently being investigated to establish genetically diverse heterotic groups.The first released spring and winter cultivars were generally characterized by good disease resistance, but low grain yield, shrivelled grain, high protein content, excessive height, lodging and preharvest sprouting. Breeding effort has increased yield, reduced shrivelling and improved test weight but at the expense of protein content, which is now comparable to wheat and rye. Plant height and lodging are also now comparable to wheat and rye. Progress in reducing preharvest sprouting by genetic selection is proving difficult and slow. Triticale may be suitable for grain production and for dual purpose usage for forage and grain.The role of biotechnology in triticale improvement is described. The future of the crop, especially in low-input systems, and as raw material for industrial uses is considered.

Knowledge of the genetic diversity of a species is important for the choice of crossing parents in line and hybrid breeding. Our objective was to investigate European winter triticale using simple sequence repeat (SSR) markers and the coancestry coefficient ( f) with regard to genetic diversity and grouping of germplasm. Three to five primer pairs for each of the 42 chromosomes were selected to analyse 128 European winter triticale varieties and breeding lines. SSR analysis resulted in the identification of 657 alleles with an average of 6.8 alleles per primer pair. The average polymorphism information content (PIC) for polymorphic markers was 0.54. Correlation between f and genetic similarity (GS) estimates based on Rogers' Distance was low (r(fxGS(ABDR))=0.33). The analysis of molecular variance (AMOVA) revealed that 84.7% of the total variation was found within breeding companies, and 15.3% among them. In conclusion, SSR markers from wheat and rye provide a powerful tool for assessing genetic diversity in triticale. Even though no distinct groups within the European winter triticale pool could be detected by principal co-ordinate analysis, this study provides basic information about the genetic relationships for breeding purposes.

a midparent grain yield heterosis of 9.5% in 31 hybrids. Oettler et al. (2003) investigated 24 winter triticale hy-Triticale (ϫTriticosecale Wittmack) (genomes AABBRR, 2n ϭ brids and estimated 10.1% midparent grain yield hetero-6x ϭ 42) hybrid breeding and heterosis have received increased attention in recent years, but a comprehensive study is lacking. We investi-sis. Weißmann and Weißmann (2002) discussed triticale gated (i) the level of heterosis, (ii) the relative importance of general hybrid breeding from a plant breeder's point of view combining ability (GCA) vs. specific combining ability (SCA), (iii) and also considered economic aspects. correlations between GCA and line per se performance, (iv) trait Owing to its genome constitution with one third of correlations in parents and hybrids, and (v) prospects for hybrid breedthe chromosomes from the allogamous rye and its floral ing. Two hundred nine F 1 hybrids of winter triticale, produced by a biology of large extruding anthers and some degree of chemical hybridizing agent, together with their 57 female parents and outcrossing (Yeung and Larter, 1972; Sowa and Krysiak, five tester (male) lines were evaluated in six environments in Germany 1996), triticale is expected to have more potential for during the season 2001-2002. Midparent heterosis for grain yield averheterosis and hybrid breeding than wheat. Modern rye aged 10.3% and varied from -11.4 to 22.4%, whereas better-parent hybrids displayed substantial midparent heterosis for heterosis averaged 5.0% and varied from -16.8 to 17.4%. Midparent grain yield (92%) and are widely cultivated in several heterosis was also positive for 1000-kernel weight, number of kernels per spike, test weight, and plant height but negative for number of European countries (Geiger and Miedaner, 1999). spikes per square meter, falling number, and protein concentration. breeding program is a sufficiently high level of heterosis. for all traits except grain yield and protein concentration. For most Previous reports based on single plants or small plot traits, GCA ϫ location and SCA ϫ location interaction variances experiments tended to overestimate heterosis. Trethowere small relative to 2 GCA and 2 SCA , respectively. Genetic correlations wan and Darvey (1994) estimated an average of 17% between midparent and hybrid performance and between GCA effects midparent grain yield heterosis in hill-plots. In small and line per se performance showed similar trends, being moderate plots of 2.5 to 3 m 2 , Oettler et al. (2001) measured 10.5%for grain yield and protein concentration and higher for the other midparent heterosis. A recent study used larger plots traits. We concluded that grain yield heterosis in winter triticale crosses

Fusarium head blight (FHB) in wheat and triticale leads to contamination of the grain with the mycotoxin deoxynivalenol (DON) that is harmful to animal and man. A fast, low-cost, and reliable method for quantification of the DON content in the grain is essential for selection. We analysed 113 wheat and 55 triticale genotypes for their symptom development on spikes, Fusarium exoantigen (ExAg) and DON content in the grain after artificial inoculation with a highly aggressive isolate of F. culmorum in three (wheat) and six (triticale) location-by-year combinations. Additionally, in triticale the amount of Fusarium damaged kernels (FDK) was assessed. ExAg content was analysed by a newly developed Fusarium-specific plate-trapped antigen enzyme-linked immunosorbent assay (PTA-ELISA) and DON content by an immunoassay. A moderate disease severity resulted in an ExAg content of 0.87 optical density (OD) units in wheat and 1.02 OD in triticale. DON content ranged from 12.0 to 105.2 mg kg −1 in wheat and from 24.2 to 74.0 mg kg −1 in triticale. Genotypic and genotype-by-environment interaction variances were significant (P < 0.01). Coefficient of phenotypic correlation between DON content analysed by the immunoassay and ExAg content was r = 0.86 for wheat and r = 0.60 for triticale. The highest correlation between DON content and symptom rating was found by FHB rating in wheat (r = 0.77) and by FDK rating in triticale (r = 0.71). In conclusion, selection for reduced FHB symptoms should lead to a correlated selection response in low fungal biomass and low DON content in the grain.

Fusarium head blight (FHB) is a widespread disease of small‐grain cereals and can cause substantial losses in grain yield. To assess quantitative genetic parameters as a basis for an efficient breeding programme for resistance, 100 triticale (×Triticosecale Wittm.) genotypes were tested in various environments and artificially inoculated at anthesis with an aggressive isolate of Fusarium culmorum. A visual rating (1–9 scale) was used to assess head blight infection. Five grain yield traits relative to an uninoculated control were also measured. The mean value of the average rating, calculated from four or five readings, was 4.4. It ranged from 3.0 to 5.9 and showed continuous variation. Infection caused a 48% reduction of mean kernel weight per spike, which was the result of 26% fewer kernels per spike and a 32% lower 1000‐kernel weight. The 50‐ml kernel weight was affected by only 20%. The range and genotypic variation was highest for relative kernel weight per spike. For all relative grain yield traits, the most important source of variation was the environment, followed by genotype‐environment interaction, with genotype generally coming last. In contrast, genotypic variation was the most important factor for the disease rating, which also had the highest heritability (h2= 0.89). Phenotypic correlations between the average head blight rating and relative grain yield traits were moderate (r = 0.42–0.57). In conclusion, an average disease rating provides a quantitative assessment of resistance and is suitable for screening large numbers of genotypes. Relative kernel weight per spike gives a ranking of the genotypes that is very similar to the visual score.