Effective Resources in Wheat and Wheat–Thinopyrum Derivatives for Resistance to Heterodera filipjevi in China

Cereal cyst nematode (CCN) is becoming one of the important soil-borne pathogens in wheat (Triticum aestivum L.) monocropping or wheat- maize (Zea mays L.)-wheat cropping systems of central China. Heterodera fi lipjevi (Madzhidov, 1981) Stelter, 1984 was recently recognized as a causal agent of CCN in China, but little informa- tion is available on sources of resistance against this nematode species. The present study was initiated to determine the current status of resis- tance in wheat cultivars against H. fi lipjevi and to identify effective resources for improvement of CCN resistance in China. A 3-yr fi eld study of CCN resistance that involved 174 wheat cul- tivars or wheat-Thinopyrum derivatives was conducted in a wheat fi eld in Xuchang, Henan Province, China, where H. fi lipjevi had been present for years. Greenhouse experiments were conducted with representative resistant entries from each group of accessions. None of the 78 wheat cultivars and breeding lines from China was resistant in fi eld tests. Wheat cultivar Madsen from Washington State was most resis- tant among the entries tested both in fi eld and under controlled environment. New sources of resistance to H. fi lipjevi were identifi ed in some wheat-intermediate wheatgrass (Thinopyrum intermedium (Host) Barkworth & D. R. Dewey) and wheat-tall wheatgrass (Thinopyrum ponti- cum (Podp.) Barkworth & D. R. Dewey) partial amphiploids, which will diversify resistance resources in enhancing resistance of wheat against CCN.