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Many natural barriers interfere with the development of functional new species from wide crosses. Among the major hurdles in the development of triticale (X Triticosecale Wittmack) were cross-incompatibility, embryo starvation, hybrid necrosis, sterility, cytogenetic malfunction, and associated endosperm malformation. By 1950, scientists had discovered ways to overcome or avoid most of the barriers and thus paved the way for triticale breeding programs. Since 1968, considerable progress has been made at the International Maize and Wheat Improvement Center (CIMMYT) in improving agronomic characteristics, seed quality, disease resistance, yield potential, and range of adaptation. Maximum grain yields in the Yaqui Valley of Mexico have increased from 2358 kg/ha in 1968 to over 8763 kg/ha in 1979. A single check cultivar of triticale (‘Mapache’) was included among 50 of the best wheat [Triticum aestivum (L.) em Thell.] cultivars in the 1977–1978 International Spring Wheat Yield Nursery (ISWYN). Out of the 71 locations around the world reporting data, Mapache was first in grain yield, averaging 4212 kg/ha. The top wheat cultivar, Nacozari, produced 4020 kg/ha. Mapache's re-sistance to rusts, smuts, mildew, and Septoria tritici Rob. ex Desm. is better than most wheats. Only in S. nodorum (Berk.) Berk. and scab were the reactions similar to those of the average wheat cultivars. Endosperm malformation still adversely influences test weight and flour quality, but progress toward well-filled kernels is being made.
In F4 progeny from the cross of triticale (X Triticosecale Wittmack) by wheat [Triticum aestivum (L.) em Thell.], from zero to seven pairs of wheat chromosomes were substituted for chromosomes from rye (Secale cereale L.). Such substitutions follow a pattern determined by characters such as the relative DNA amount of individual rye chromosomes and nucleolar organizing ability. Triticales also contain chromosomes from rye modified by the loss of telomeric hetero-chromatin. Strong correlations exist between the presence of such heterochromatin, the degree of several cytological abnormalities, and grain shriveling. Modified rye chromosomes were combined into triticales with a common genetic background. The additive effects of these modified chromosomes on cytological stability and grain shriveling were analyzed. Based on selection for nucleotypic rather than genic characters, this work is the first example of chromosome engineering involving the controlled reduction of DNA amount and type in a crop species. Rye telomeres contain several highly repeated DNA sequences available as “hot probes” after plasmid cloning. Their use for identifying chromosomes in triticale is being investigated.
In the 1977–1978 growing season, over 625 triticale lines (X Triticosecale Wittmack) along with 150 rye (Secale cereale L.) and 80 wheat lines [Triticum aestivum (L.) em Thell.] were screened for trypsin inhibitor levels. Generally, wheat trypsin units inhibited (TUI) per milliliter of extract were relatively low, whereas levels for winter rye were usually very high. Self-fertile spring rye lines, however, exhibited a wide range in TUI levels. The spring and winter triticale lines exhibited values ranging from the mean of the wheat lines to the mean of the winter rye lines. The trypsin inhibitor levels of nine selected winter triticale lines and a winter wheat cultivar were studied in a 3-year, four-location test. The TUI/mL of extract varied significantly with both season and location, with season being the most important factor. Within triticale line T1015, a maximum range of 39 units was obtained between different years at the same location. Sufficient variability is available in current triticale materials for selection of low trypsin inhibitor lines. Further, self-fertile rye lines with low trypsin inhibitor levels can be used as parent material to produce triticale with low trypsin inhibitor levels. This use offers an alternative approach to triticale breeding.
Triticale (X Triticosecale Wittmack) cultivars and breeding lines grown in Washington in 1978 contained from 125 to 177 g/kg of crude protein. Feeding trials with young chicks and laying hens (Gallus domesticus) showed that triticale supported growth and feed efficiency in chicks comparable to results obtained with corn (Zea mays L.) or soft white wheat [Triticum aestivum (L.) em Thell.] when triticale was used as the only grain in the feed. Because of the higher protein concentration of the triticale, the amount of soybean (Glycine max L. Merr.) meal required was greatly reduced. In trials with laying hens, two different cultivars supported egg production rates that were comparable to results obtained with diets containing either corn or soft white wheat. In this trial, triticales replaced all or part of the corn in the control diet; when all of the corn was replaced by triticale, the triticale constituted approximately 80 % of the diet. In another trial with laying hens conducted to determine whether supplemental lysine was required when triticale was the only grain in the feed, the unsupplemented diet gave results that were equal to those with the corn-soybean control diets. Thus, the level and availability of lysine were adequate to meet the needs of the hen for egg production. A number of the triticales are being analyzed for amino acid content and metabolizable energy.
Two feeding studies were conducted with pigs (Sus domesticus) fed triticale (X Triticosecale Wittmack). A palatability study was conducted with 24 Yorkshire-Hampshire weanling pigs (8.7-kg body weight) given the choice of either a basal corn-soybean [Glycine max (L.) Merr.-Zea mays L.] meal pig starter diet or one diet containing triticale (Beagle subline) as 33, 67, or 100% replacement of corn. The second study evaluated the low trypsin inhibitor activity of triticale (Beagle subline), 24 trypsin units inhibited (TUI), by using it as a grain replacement for proso millet (Panicum miliaceum L. cv. Minco) (2 TUI) in swine starter, grower, and finisher diets. Based on the results of the aforementioned studies, economic evaluations of triticale in swine diets were projected using linear programming. Results from the palatability study indicated pigs did not discriminate against triticale. In the second study, daily gain and feed/gain ratio were similar across treatment groups. Pig body weight gain and feed efficiency were negatively correlated with diet trypsin inhibitor activity (TIA), r = −0.59 and r = −0.18, respectively. Neither the level of triticale in the diet nor the level of TIA affected actual or relative pancreas weight of the pigs at the time of slaughter. When least-cost diets for swine were formulated using the nutrients in triticale, the amount of soybean meal needed to balance diets, was reduced, which, in turn, substantially reduced diet cost.
Triticale (X Triticosecale Wittmack) evaluation and improvement in Oregon has evolved from the introduction of and selection within spring types to the evaluation and selection of winter triticales and the synthesis of new triticales through crossing of adapted winter wheats [Triticum aestivum (L.) em Thell.] with ryes (Secale cereale L.). We have identified several promising niches in the state where growers may accept triticale. Fertile, winter hardy, and snow mold and frost-heaving resistant cultivars have been found in the Oregon screening nurseries at the 1000 to 1400 m-elevation intermountain sites. Several winter triticales planted on the windswept irrigated sandy soils along the Columbia River have yielded as well as commercial wheats, show no barley yellow dwarf virus damage, and could serve as both a cover and a grain crop. Triticales tolerant to diseases, wet winter soils, and aluminum toxicity have yielded competitively with winter wheats in the Willamette Valley. In southern Oregon, spring triticale may prove suitable for the Klamath Basin.
Triticale (X Triticosecale Wittmack) cultivars have been evaluated extensively in Oklahoma, Texas, and New Mexico. Grain yields of the more productive triticale have averaged 5 to 10% less than that of wheat [Triticum aestivum (L.) em Thell.], but some lines and cultivars have slightly exceeded the yield of wheat in recent years. Triticale yields, however, have been more variable than those of wheat. Test weight and overall grain quality in triticale are major faults, but some improvement in test weight has been observed in recent selections.
Forage yields of the most productive triticales have equaled the yields of the most productive wheats in the northern part of the region but have averaged less than rye (Secale cereale L.). Triticales grown in central and southern Texas have competed well with oats (Avena sativa L.) as a forage crop some years because of their greater resistance to foliar diseases usually prevalent in these areas.
It appears that cultivars of triticale presently available are not highly competitive with rye solely as a forage crop and not competitive with wheat, in the absence of sizeable and stable grain markets, as a dual purpose crop in the Southern Great Plains. Shorter height, earlier maturity, uniform ripening, and thresh-ability are needed improvements.
The adaptation and performance of 20 triticale (X Triticosecale Wittmack) cultivars grown in 15 environments in the Uniform Triticale Yield Nursery were studied. Cultivars responded differently in different environments. Location and cultivar × location mean squares were significantly different at the 1 % level of probability. Cultivars OK-77802 and OK-77803 had the highest mean grain yields in 15 environments, with regression coefficients of 1.205 and 0.990, respectively. Cultivar 6TB-225 had the highest regression coefficient (1.352) and was the highest-yielding cultivar at five locations. The highest grain yield was recorded at Fort Collins, CO, followed by Davis, CA. Simple correlation coefficients indicated the similarity in performance at Huntsville, AL; Wooster, OH; and Knoxville, TN. Additional testing of a number of triticale cultivars at these locations is suggested.
Research on triticale (X Triticosecale Wittmack) in California began in 1968. The development of this new cereal as an agronomic crop and also its potential in wheat improvement have received emphasis. Major efforts have centered on the synthesis of new triticale, breeding, studies of crop adaptation, and crop utilization.
Experience and results in California complements work in other regions. Genetic improvement in yield and agronomic traits has been rapid, and now triticales are equal to or better than wheat in grain yield performance. No substantial agronomic management adjustments need to be made, although earlier planting for triticale than wheat is advantageous. The wide range of potential uses for triticale in animal nutrition has been confirmed in several California studies. Its use as an adjuvant in brewing is promising.