A black soybean cultivar called ‘Noksim’ was developed using pedigree selection by crossing ‘Ilpumgeomjeong’ (SLSB87-3 × YS558) and ‘PI547426’. A p reliminary y ield t rial (PYT), advanced y ield t rial (AYT), and regional y ield t rial (RYT) were conducted in t hree regions. ‘Noksim’ has a determinate growth habit, purple flowers, and spherical seeds. In the regional yield trial, the flowering and maturity dates of ‘Noksim’ were August 4 and October 13, respectively, and its 100-seed weight was 26.5 g, which was lower than that of ‘Chungja 3’ (36.5 g). Additionally, ‘Noksim’ showed resistance to lodging, soybean mosaic virus (SMV), bacterial blight, and pod shattering. In terms of the seed quality, the chlorophyll content of ‘Noksim’ was 71.19%, which was higher than that of ‘Chungja 3’ (50.78%), and its total anthocy anin c ontent w as 2 5.17 m g/100g, w hich w as t hree t imes more than t hat of ‘Chungja 3’. The mean y ield o f ‘Noksim’ i n RYT was 2.35 ton/ha, which was 18% greater than that of ‘Chungja 3’. ‘Noksim’ is suitable for cooking with rice and soy products such as soymilk because of its high brix degree (35 Brix) after cooking with rice, as well as its soymilk yield (71.2%). Overall, ‘Noksim’ has dark green cotyledons with a black seed coat that is preferred by consumers, and its early maturity with pod shattering resistance results in an increased seed yield. (Registration No. 7734).
A yellow soybean cultivar called ‘Hipro’ was developed using the single seed descent (SSD) method by crossing ‘Saedanbaek’ (SS92414 ×MD87L) and ‘Daepung’ (Baekwon × Sinpaldal2). A preliminary yield trial (PYT), advanced yield trial (AYT), and regional yield trial (RYT) were conducted in three regions. ‘Hipro’ has a determinate growth habit, white flowers, and a spherical seed shape. In the regional yield trial, the flowering and maturity dates of ‘Hipro’ were August 4 and October 17, respectively, and the 100-seed weight was 22.2 g, which was lower than that of Daewon (26 g). Additionally, ‘Hipro’ showed resistance to lodging, soybean mosaic virus (SMV), bacterial blight, and pod shattering. The seed protein content of ‘Hipro’, which was of particular interest in this study, was 53.9%, which was higher than that of ‘Daepung’ (41.5%), and the total amino acid content without tryptophan was 43.6%, 19% higher than that of ‘Daepung’. The mean yield of ‘Hipro’ in RYT was 2.23 ton/ha, which was 91.3% of the yield of ‘Daewon’. However, ‘Hipro’ showed an 11% higher yield than Daewon in Paju. As a result of the tofu characteristic test, 'Hipro' is suitable for making soy milk and tofu due to its high solid content (12.67 Brix) and protein content (13.68%) and high yield (325%) of tofu. Overall, ‘Hipro’ had high protein content, excellent processing quality for tofu and soy milk, and strong resistance to disease and pod shattering that will greatly contribute to the consumption of soybeans in Korea. (Registration No. 7735).
Water use efficiency (WUE) is considered as an important characteristics of drought tolerance in crop plant. This study was carried out for determination of WUE of 29 Korean soybean cultivars including PI416937, a representative drought tolerant cultivar in USA, under two different soil water contents, the sustaining 50% of maximum field capacity on control and 25% on drought treatment for 14 days at the late of vegetative growth stage. The WUE of whole plant (g/L) was determined using the measurement of the amount of water use (mL/day/plant), dry weight (g/plant), and relative growth rate (RGR) at 14 days after treatment (DAT). The mean amount of water use of 30 soybeans was 183 and 64 mL/plant/day at control and treatment, respectively, which was decreased 63% of water use under 25% of maximum field capacity. The mean dry weight of 30 soybeans of treatment was decreased 37% compared with that of control. The amount of water use of 30 soybeans was highly correlated with dry weight at 14 DAT, while it was weak correlated with RGR of treatment and not correlated with WUE. The WUE was highly correlated with RGR at control and treatment. The mean WUE of 30 soybean was 2.1 and 2.9g/L at control and treatment, respectively. It means that WUE is increased under drought condition and is the variable characteristics depend on soil water content. The WUE of PI416937 was 3.5g/L at treatment. This study suggested WUEs of 29 Korean soybean cultivars and that the higher WUE Korean cultivars than PI416937 were 3 cultivars, Daepoong (3.8g/L), Danbeak (4.0g/L), and Keumkang (3.8g/L).