Genetic Yield Potential Improvement of Semidwarf Winter Wheat in the Great Plains

摘要

Recently, private companies and public entities have made significant investments in and improvements to their wheat (Triticum aestivum L.) breeding programs. Because of this increased interest, genetic improvements made in wheat through traditional plant breeding need to be analyzed. Many studies noted the significant yield improvement from tall cultivars to semidwarf cultivars, but no studies have documented improvements made from the earliest semidwarfs to present-day cultivars. Thirty cultivars were tested including two tall (Kharkof, released in 1919, and Triumph 64, released in 1964) and 28 semidwarf cultivars spanning the period from 1971 (TAM 101) to 2008 (Jackpot and TAM 401). Cultivars were tested in 2010 and 2011 at 11 locations across Oklahoma, Kansas, and Texas with fertilizer and fungicide for adequate disease protection. Increases in breeding for yield stability have been made over time. A significant yield increase of 14.607 kg haa?’1 yra?’1 or 0.93% per year of Kharkof yield was obtained across all locations with the tall cultivars included. When gain was restricted to only semidwarf cultivars (1971 to 2008), yield gain was reduced to 11.03 kg haa?’1 yra?’1 or 0.40% per year of TAM 101 (1971) yield. No evidence of a yield plateau was found.