Genetic parameters estimation in quantitative traits of a cross of triticale (x Triticosecale W.)

Abstract

Triticale (x Triticosecale Wittmack) is a cereal used in Argentina as a winter seasonal pasture or feeding grain. Efforts made on breeding have led to varieties with potential grain yield similar or greater than with wheat. The aim of this study was to determine the gene effects, heritability, genetic gain, heterosis and inbreeding depression in various quantitative traits of a cross from contrasting lines of triticale using generation means analysis. The thousand kernel weight was adjusted to a model of additive-dominance, while the rest of the traits exhibited significant epistatic effects: additive x additive (i) for hectoliter weight, additive x dominance (j) for number grains per spike and grain yield per plant. Other traits showed a more complex as inheritance additive x additive (i) and additive x dominance (j) interactions effects for spike length or additive x dominance (j) and dominance x dominance (l) interactions effects for number of spikes per plant and number of spikelets per spike. High values of heritability and genetic gain were also detected for grain yield, spikelets per spike, spike per plant and hectoliter weight. All traits except spike per plant had positive relative mid-parent heterosis, but none resulted in positive heterobeltiosis, therefore this cross is not recommended for obtaining hybrids varieties. Selection in early generations by thousand kernel weight and hectoliter weight would be efficient, while the selection in advanced generations where segregation is minimal would be recommended for the remaining traits.

Keywords

• gene effects
• heritability
• heterosis
• generation means analysis