New Resources Of Cereal Cyst Nematode (Resistance To Heterodera Filipjevi And H. Avenae)

Cereal cyst nematodes (CCN) are a group of important soil-borne pathogens ofwheat. Heterodera avenae and H. filipjevi are the major species of CCN that havelimited wheat (Triticum aestivum) production in China in recent years. Since theCCN-resistant resource is short, it is important to develop new sources with resistancefor breeding purpose in China.Based on the results of a3-year field test and controlled environment tests, wefound that two Canadian Triticum durum cultivars, Waskana and Waskowa, werehighly resistant to both Heterodera filipjevi (pathotype Hfc-1) and H. avenae(pathotype Ha43) populations from Henan Province, China. The number of whitefemales per plant in Waskana and Waskowa was significantly smaller than that in thesusceptible common wheat cultivars Aikang58, Shi4185, and Wenmai19. Althoughthe juveniles of H. filipjevi and H. avenae populations were able to penetrate into theroots of Waskana and Waskowa, the number of juveniles inside the roots wassignificantly smaller than that of Aikang58, Shi4185, and Wenmai19, resulting insmaller numbers of females on the roots of these durum wheat cultivars. Waskana andWaskowa with resistance to H. filipjevi and H. avenae are useful in developing wheatcultivars with enhanced resistance to CCN in China. Based on the results from theDNA-based soil testing service operated by South Australian Research andDevelopment Institute, the number of eggs of nematodes in the rhizospheric soilsamples from the CCN-resistant cultivars Waskana and Waskowa was less than thatin the soil samples from the susceptible wheat cultivars. This indicates thatapplication of resistant cultivars might reduce the risk of damage caused by CCN insoil.In a three-year filed test in Xuchang, Henan Province, the wheat cultivar Madsenwas highly resistant to H. filipjevi. Inoculation tests in controlled environments with11pathotypes of H. filipjevi and H. avenae from Henan, Anhui, and Shandongprovinces demonstrated that Madsen was effective against most of these pathotypes.The populations of H. filipjevi from Xuchang, and H. avenae population fromZhengzhou, Henan Province were used to test four F2populations derived from the crosses between Madsen and Yannong21, Longfumai10, Jinmai47, and Xumai856respectively. A segregation ratio of3:1was observed in both field and artificialinoculation tests. This indicated that a single dominant gene was associated with theresistance of Madsen to H. filipjevi. Using SSR markers, the resistance gene inMadsen was localized an interval between the markers WMS636and WMC296onchromosome arm2AS with the genetic distances of21.3cM and16.2cM,respectively. In addition, molecular analysis was conducted to understand thechromosome compositions of Madsen.