KAS360-22 종자에 1998년 250 Gy의 감마선을 조사하였다. 그 후대에서 미이라병에 저항성을 가지는 계통을 선발･육성하여, ‘원율’로 명명하고 2009년에 최종적으로 품종보호권을 출원 신청하여 2012년 등록 완료하였다. 원품종 KAS360-22의 종피색이 노란색인데 반하여 신품종 ‘원율’은 갈색을 나타냈다. 100립중은 재래종 KAS360-22이 17.2 g, ‘원율’은 27.5 g으로 종자무게는 증가하였으며, ‘일품검정콩’(27.4g)과는 별다른 차이를 보이지 않았다. 신품종 ‘원율’의 10a 당 수량은 미이라병 발병 조건에서 233.3 kg으로 재래종 KAS360-22 (24.9 kg)에 비교하여 10.6배 가량 높았고, 대조구 ‘일품검정콩’(121.4 kg)에 비교하여도 1.9배 가량 높아 밥밑용 콩으로 안정적인 수량 확보가 가능할 것으로 사료된다.

Phomopsis seed decay (PSD), primarily caused by Phomopsis longicolla, is a major contributor to poor soybean seed quality and significant yield loss, particularly in early maturing soybean genotypes. However, it is not yet known whether PSD resistance is associated with early maturity. This study was conducted to identify quantitative trait loci (QTLs) for resistance to PSD and maturity time using a recombinant inbred line (RIL) population derived from a cross between the PSD-resistant Taekwangkong and the PSD-susceptible SS2-2. Based on a genetic linkage map incorporating 117 simple sequence repeat markers, QTL analysis revealed two and three QTLs conferring PSD resistance and maturity time, respectively, in the RIL population. Two QTLs (PSD-6-1 and PSD-10-2) for PSD resistance were identified in the intervals of Satt100-Satt460 and Sat_038-Satt243 on chromosomes (Chrs) 6 and 10, respectively. These QTLs do not overlap with any previously reported loci for PSD resistance in other soybean genotypes. Two QTLs explained phenotypic variances in PSD resistance of 46.3% and 14.1%, respectively. Among three QTLs for maturity time, two (Mat-6-2 and Mat-10-3) were located at positions similar to the PSD resistance QTLs. The identification of the QTLs linked to both PSD resistance and maturity time indicates a biological correlation between these two traits. The newly identified QTLs for resistance to PSD associated with maturity time in Taekwangkong will help improve soybean resistance to P. longicolla.

Phomopsis seed decay (PSD) is part of a major fungal disease complex found in most soybean production areas of the world. To establish the genetic linkage map and efficient soybean breeding program, DNA markers were surveyed for polymorphism between PSD resistant (cv. PI 417479) and susceptible (cv. Hwaeomput-kong) varieties. F2, BC1F2, BC2F2 and the corresponding F2:3 population families were used to evaluate the correlation between molecular markers and resistance to PSD. In SSR analysis, Sct_033 was the most significantly associated with PSD resistance among selected eight primers. AF1, AF2, and AF3 were also selected in AFLP analysis. And a few promising lines could be selected from two times of back cross. Especially a breeding line SS01415-8-1 was developed, which has high seed quality such a large seed size, bright hilum color, round shape, and etc. It might be considered a good breeding material for new recommend variety having resistance gene to PSD with good seed quality.