Soybean Cyst Nematode (Heterodera Glycines Ichinohe) Races And Inheritance And Gene Mapping Of Resistance Of Soybeans To The Disease In Huang-Huai Valleys

Soybean cyst nematode (SCN, Heterodera glycines Ichinohe) is a severe pathogen worldwide. Great yield loss has been caused by SCN every year in the main soybean production countries such as USA, Brazil, Argentina and China. Development of resistant cultivars is an effective way to control the pathogen. Literature reports had shown that, in Huang-huai velleys, one of the main soybean production areas in China, SCN had already existed widely, while most of the previous reports were limited in a single province or site. ZDD2315 and ZDD2226 had been identified as elite resistance sources which were resistant to Race 1, 3, 4, and 5, but little was known about the genetic mechanism of these two lines resistant to different SCN Races. The main goals of this study were: (1) confirmation of the dominant SCN Races in Huang-huai valleys through deep investigation based on the results of related literature; (2) revelation of genetic mechanism of ZDD2315 and ZDD2226 resistant to dominant Races; (3) QTL mapping of resistant genes. The results of this study will be helpful for development of resistant cultivars in this area.A total of 38 sites in Huang-Huai Valleys were sampled and identified for the distribution of soybean cyst nematode (SCN, Heterodera glycines Ichinohe) Races during 2001- 2003. A map of race distribution was constructed according to the data from this experiment and literature cited. Three areas mainly infested with Race 1 were identified, i.e. the area south-east to Jinan in Shangdong province, the area of northern Henan province and its border region to south of Hebei province, and the area of Luohe, Zhoukou of Henan province and Fuyang of Anhui province. Race 4 was predominant in Shanxi province, Beijing and the adjacent area of Henan, Shandong and Anhui provinces, and the delta of Huanghe River in Shandong province. Race 2 was mainly in Liaocheng, Dezhou of Shangdong province and Shijiazhuang of Hebei province, and Jiaozuo and Huojia of Henan province. Race 7 distributed in the west part of Jiaodong peninsula of Shandong province and Kaifeng, Huaxian, Wenxian of Henan province. Race 5 was found scattering in Hebei and Henan province. Race 9 was found in Shangqiu of Henan province, which was reported the first time in China. From the above, Race 1 and Race 4 were the two predominant races in Huang-Huai Valleys, which should be focused on for developing resistance cultivars. There might exist other races in an area with some predominant race. The race change in the past decade was not obvious, therefore, the results were meaningful to the present breeding for resistance to SCN in Huang-Huai Valleys.Mainly focusing on the dominant Races, Race 1 and 4, the following work would aim to reveal the genetic mechanism of ZDD2315 and ZDD2226 resistant to the two Races.