Triticale, Still a Promise?

Abstract

Experiments with primary triticale genotypes produced from defined wheat and rye parents provide a strong indication of a preponderance of specific genome combining ability in the phenotypic expression of triticale. Studying line families developed from specific cross combinations by means of the single seed descent method revealed that, in contrast to wheat, the distribution of genotypes in an F2 population of triticale is strongly skewed, with the majority of them being inferior to the mid-parent value. This is the case even if recombination is restricted to one fourth of one of the parental components of triticale, i.e. wheat or rye. Correlations of yield components were found to deviate substantially from known types of correlations in wheat, an established natural allopolyploid species. These findings give a strong indication for a genomic inbalance in triticale being a major cause for slow advance in varietal improvement. New breeding strategies designed for the specific genetic structure of triticale are necessary to accelerate breeding progress and to help triticale ultimately to live up to its promise.

Analysis of self-fertilization and meiotic behavior of eleven Brazilian triticale cultivars at two sowing dates

“…The cell cycle duration may also act in the irregularities observed in triticale. According Sisodia and Mcginnis (1970) and Lelley (1992), differences in the meiotic cycle of two parents generate irregularities in this species, as the presence of univalents.…”

“…Tetraploid triticales are agronomically inferior, showing poor protein quality and high sterility (Hohmann 1993), while hexaploids and octaploids have superior agronomic traits. Hexaploids are the most widely cultivated triticales due to their grain yield superiority (Lelley 1992).…”

Backcrossing to increase meiotic stability in triticale

“…This abnormality is commonly found in plants such as maize (CaetanoPereira et al, 1995), canola (Souza and Pagliarini, 1996), Centella asiatica (Consolaro and Pagliarini, 1996), and Brachiaria sp (Mendes-Bonato et al, 2001), among other species. In triticale, chromosome stickiness and associations can be attributed to the presence of rye chromosomes, which were indicated as a factor involved in the development of irregularities by Jung et al (1985), Lelley (1992), and by Varghese and Lelley (1983).…”

“…This artificial hybrid succeeded in combining key attributes of the two parental species, which are the high productivity and energy value of wheat and the resistance to environmental stresses and elevated protein level of rye (Oetller, 2005). Triticale is primarily self-pollinated, although it may undergo some cross-pollination (Oettler et al, 1991;Lelley, 1992).…”

Stomatal movements and gas exchanges of a triticale and its parental species in water-stress conditions

“…Under water stress, water loss was avoided by stomatal closure in rye and Triticum df, whereas in T300 the stomata stayed open and gas exchange were lower than in control plants. stomata (Vermorel and Bernard, 1979 (Hulse 1974;Cauderon, 1981) but the breakthrough for triticale is still awaited (Lelley, 1992 (Jensen and Jönssen, 1981;Mashhady et al, 1982;Touraine and Ammar, 1985; Gorham, 1990;Giunta et al, 1993;Josephides, 1993 Louguet (1969 …”