Triticale: Potential and Research Status of a Man-Made Cereal Crop

Abstract

Triticale (Tcl) improvement concentrates on generating various crop and utilization options. These are associated with crop adaptive patterns, economic comparative advantages, issues of environmental sustainability, as well as issues of consumption, marketing, and end uses. By focusing on Tcl’s comparative advantages over other crops regarding these options, CIMMYT has shifted its Tcl breeding objectives. International yield data and past experience indicate high genetic progress in Tcl grain yield under marginal and high production conditions (> 1.5%/year). Since grain yield in marginal environments reflects the genotypic response to the total environment, progress has to be associated with advances for all biotic and abiotic factors involved. Under near optimal conditions, comparison in maximum yield trials at Cd. Obregon over three location years of Tcls developed in the 1980s and 1990s reveals overall yield progress to be at +17% due to increases in harvest index (+16%), grain biomass production rate (+21%), grains/m² (+17%), spikes/m² (+12%), and test weight (+12%) and a decrease in height (-11%). Genetic variabilities for these traits suggest that gains in genetic grain yield potential can be maintained in the future. High rates of progress in germplasm developed from crosses involving interspecific Tcl x wheat, spring x winter Tcl, and 2D(2R) x complete R type suggest that these gene pools are promising sources with which to achieve future genetic gains. The shift in breeding emphasis to complete R genome and 6D(6A) types in the 1980s was accompanied by improved test weights, but negative effects on baking quality. Subsequent research with wheat-Tcl grain and flour blends on milling and baking properties suggested blends for commercial use. In 1990, specialized requirements and markets for products for human consumption, feed grain, and growing interest in forage and dual purpose triticales were prompted by end-use oriented and expanded breeding objectives. By 1994, germplasm products for the range of utilizations are available. Current quality improvement hinges on introgressing high-molecular-weight glutenin subunits, particularly allelic variants at loci Glu-D1, Glu-B1 and Glu-Al. Spectacular increases in SDS sedimentation in 1D(1A), 1D(1B), and 1Rs.1Dl Tcls that carry D genome non-enzymatic storage proteins suggest a future breakthrough in improving Tel’s industrial quality, while additional gains can be expected from exploiting gliadins and secalins.

Early forage research in 1990 concentrated on determining the forage potential of STcl/FTcl compared with oats and barley as alternate forage commodities in one-cut situations. Results suggested that existing STcls were suitable for early forage, hay, and whole-crop silage. From 1991 onwards, a representative sample of the late STcl, FTcl, and WTcl gene pool was evaluated for forage potential in multiple forage harvests and grain-recovery potential [9]. Guided by results and implications, a new international nursery (FWTcl) was assembled including advanced and segregating FTcl and WTcl grain and forage materials and distributed to 75 cooperators. Parallel to the dissemination effort, traits such as reduced awns from different sources were identified, evaluated, and incorporated in the target gene pool.