A New White Wheat Cultivar, “Jokyoung” for Bread Making

“Jokyoung”, a new bread making wheat cultivar, was developed from the cross between “Seri 82”, a hard white wheat from CIMMYT, Mexico and “Keumkang”, a hard white wheat with high milling rate and early maturing from Korea by National Institute of Crop Science, RDA, Korea in 2004. Among the crosses made in 1995, a promising line, YW2743-2B-18-3-1, showed good quality for bread making in the yield trial tested in Suwon in 2001, and was designated as Suwon 298. It showed very good bread making quality, but less grain yield in the Regional Yield Trials in four locations around Korea for three years from 2002 to 2004, and was released as the name of “Jokyoung”. It belongs to the growth habit of II, and has light green leaf, long spike, large grain, and white grain color. Its heading date was April 25 in upland and April 19 in paddy field conditions, which were three and four days earlier than those of the check cultivar Urimil, respectively, and maturing date was June 8 in upland and June 2 in paddy field, two or three days earlier than those of Urimil, respectively. The new cultivar, “Jokyoung”, kept 81 cm of culm length that was 3 cm shorter than that of Urimil, and 8.0 cm of spike length. It showed 747 in the number of spikes per m², 34 of grain number per spike, 44.6 g of 1000 grain weight, and 788 g of test weight. “Jokyoung” also showed weak winter hardiness, but better tolerance to lodging than those of the check cultivar Urimil. The average grain yield in the regional yield trial was 6.38 MT/ha in upland and 5.19 MT/ha in paddy field, which were 7% and 9% lower than those of the check cultivar, Urimil, respectively. Meanwhile, Jokyoung showed higher milling rate, higher milling score, higher protein content, and much more sedimentation volume than those of Urimil, In the Alveogram, tenacity and elasticity, and bread making ability of Jokyoung were much better than those of the check cultivar. It showed good crust and uniform crumb structure as well as high loaf volume and weight compared to “Keumkang”, which has been the check cultivar for bread use in Korea. This cultivar is suitable for the area above the daily minimum temperature of −8℃ on average of January on the Korean peninsula.