Heterosis of Avenae SPP. in closely spaced plantings

Abstract

An evaluation of heterosis in Avenae spp. Was conducted to estimate heterosis in grain yield, yield components, total air dry weight, straw weight, height, heading date, growth habit, percent groat protein and bushel weight. Ten pure-line varieties were used to produce seven F₁ hybrids by the approach cross method. The plants were started in the greenhouse in peat cups and transplanted to the field at rates approaching normal field stands. Within-cross comparisons were made among parents, F₁'s and F₂'s for all characters tested. Heterosis for the characters were expressed quite differently in the F₁'s. Some F₁'s exhibited heterosis for most characters tested, but others exhibited heterosis for only a few characters. Grain yield, total air dry weight and straw weight were the characters which showed the greatest and most consistent heterosis. Heterosis for grain yield was observed in all crosses and ranged from 6 to 130% that of the higher grain yielding parent. One cross surpassed the best pure-line variety tested by more than 35%, indicating superior hybrids might substantially increase grain yields if hybrids were commercially available. F₁'s with high grain yields appeared to result from a favorable combination of parental yield components acting in a multiplicative manner. High-parent heterosis values ranged from 3 to 85% for total air dry weight and 0 to 76% for straw weight. Several crosses exhibited high-parent heterosis for all these characters suggesting that F₁'s might have several economic and/or agronomic advantages over pure-line varieties. Seed per panicle was the yield component which showed the greatest and most consistent heterosis. Some F₁'s also were found to exhibit heterosis for height, heading date, growth habit, and bushel weight.