Bacterial pustule is a major bacterial disease in most soybean-growing regions of Korea, resulting in soybean yield reductions of up to 60%. In this study, we aimed to understand the differences in disease severity caused by three strains of Xanthomonas citri pv. glycines, including two newly differentiated strains (K29 and K100) and the conventional representative strain, 8ra. Seventeen major soybean cultivars and 14 breeding lines were inoculated and compared for their reactions to the three strains of Xcg. The two new strains caused higher levels of disease severity, resulting in a greater number of susceptible cultivars. The landrace PI 547711, like Williams 82, was highly resistant to all Xcg strains; however, the other six cultivars that were resistant to 8ra, including Daepung2, were susceptible to the new strains (K29 and K100). In particular, the most widely grown cultivars, Daewon and Daepung2, were highly susceptible to K100. All of the breeding lines except two were also vulnerable to the new strains, K100 and K29. Of the breeding lines, SS05004-1-1-4-2-3-4 and SS05022-5-4-2-4-4-4 were resistant to the three Xcg strains, at similar levels to that of Williams 82. The breeding lines and cultivars evaluated in this study may be used to develop breeding materials resistant to new Xcg strains in the future. In addition, establishment of an improved disease evaluation system for bacterial pustule, by using multiple representative strains, is strongly recommended for breeding programs, to increase the efficiency and accuracy of selection for resistance as the pathogenic diversity of X. citri pv. glycines changes.

A new soybean variety, ‘Joongmo 3009’ (Milyang 222) was developed at the National Institute of Crop Science (NICS) in 2012. ‘Joongmo 3009’ was released by pedigree selection from the cross between ‘Cheongja 2(Milyang 121)’ and ‘Daemangkong’.

It has determinate growth habit, white flower, brown pubescence, brown pod color, green seed coat, green cotyledon, spherical seed shape, oval leaf shape and large seed size (29.3 grams per 100 seeds). It was late 16 days in maturing date than the check cultivar ‘Cheongjakong’. The average yield of ‘Joongmo 3009’ was 2.91 ton per hectare, which was higher 36 percentage than the check variety, in the regional yield trials carried out in three adaptable locations of Korea from 2010 to 2012. The number of breeder’s right is ‘5474’

A soybean cultivar ‘Yonpoong’ which has safety high yield for double cropping system introduced winter forage crop was released by agricultural resource research institute of ARES, Gyeunggi Province in 2010. The goals of breeding were for large seed size, high yield, and resistance to disease such as spotting disease. ‘Yonpoong’ was derived from the cross of ‘Suwon 191’, which large seed size and high yield, and ‘Suwon 126’, which early maturity cultivar, and short stem. The preliminary, advanced and regional yield trials for evaluation and selection were carried out from 2005 to 2010. ‘Yonpoong’ has a determinate growth habit with purple flower, grey pubescence, brown pod color, yellow seed coat, yellow cotyledon, elongated seed shape, large seed size(28.7 g per 100 seeds). The maturing date was sept. 22. Tofu yield was similar to that of check cultivar ‘Daewonkong’. The average yield of ‘Yonpoong’ was 3.34 MT/ha in the regional yield trials(RTY) carried out in Korea from 2008 to 2010 which 38 percent higher than the check cultivar ‘Daewonkong’.

A new soybean cultivar ‘Manpoong’ for tofu soybean was released by ARES, Gyeunggi Province in 2009. The goals of breeding were for large seed size, high yield, and resistance to disease such as bacterial pustule. ‘Manpoong’ was derived from the cross between ‘Dongsan 121’, which has large seed size, yellow seed coat, and characteristics of superior tofu, and ‘Sprite 87’, which has early maturity. The preliminary, advanced and regional yield trials for evaluation and selection were carried out in 2003 and from 2005 to 2009, respectively. ‘Manpoong’ has a determinate growth habit with white flower, grey pubescence, dark brown pod color, yellow seed coat, yellow cotyledon, elongated seed shape, and large seed size(29.5 g per 100 seeds). The maturing date was Sept. 29. The content of crude protein, crude oil, unsat. fatty acids, isoflavone, total amino acid which affected the production rate of tofu was higher than those of the check cultivar ‘Taekwangkong’. The production rate of tofu was 15 percent higher than the check cultivar ‘Taekwangkong’. The average yield of ‘Manpoong’ was 2.87 MT/ha in the regional yield trials(RYT) carried out in two location at double cropping system in Korea from 2007 to 2009, which was 12 percent higher than the check cultivar ‘Taekwangkong’.