Characterization of Resistance to the Cereal Cyst Nematode in the Soft White Winter Wheat 'Madsen'.

The cereal cyst nematode (CCN) has a significant negative impact on production of wheat in China. The presence of pathotypes of both Heterodera avenae and H. filipjevi makes it necessary to identify genetic resources with a wide spectrum of resistance. Results of this study confirmed that the soft white winter wheat 'Madsen' was resistant to many different populations of both H. filipjevi and H. avenae in both naturally infested fields and artificial inoculation tests in China. Fewer juvenile nematodes penetrated roots of Madsen than susceptible 'Wenmai 19' in the early stages of the interaction between the nematodes and plant. Testing wheat cultivars in the pedigree of Madsen demonstrated that the CCN resistance of Madsen was inherited from 'VPM1' via the line 'VPM1/Moisson 951'. Presence of a 2NS chromosome segment from Aegilops ventricosa was detected in Madsen using a Vrga1D-specific marker. However, it appears that gene Pm4b for resistance to powdery mildew (caused by Blumeria graminis f. sp. tritici) was not transferred from VPM1 into Madsen because these cultivars had different reaction patterns against 20 B. graminis f. sp. tritici isolates from China. Madsen serves as an effective source of host resistance from damage caused by CCN.