Gene effects for spike length, spikelets per spike and spike density in Hordeum chilense

Hordeum chilense Roem. et Schult. is a South American wild barley that occurs exclusively in Chile and Argentina, where it is a component of natural pastures. This species has been crossed with durum and bread wheats to obtain a new amphiploid, called tritordeum, which presents agronomic traits of a new crop. Two groups represented by H1 and H7 lines have shown differences for spike length and density, number of spikelets per spike and various other characters which are interesting for tritordeum improvement. This study was conducted to investigate inheritance of these three characters in a cross between H1 and H7 lines, including parents, F 1 and F 2 generations. The three characters studied fitted the additive model. The dominance effects were less strong than the additive effects, indicating partial dominance of positive sign for number of spikelets per spike; whereas spike length displayed small dominance effects of negative sign and the spike density showed intermediate inheritance, with the inheritance being almost exclusively additive