Effective Resources in Wheat and Wheat-Thinopyrum Derivatives for Resistance to Heterodera fihipjevi in China.

Cereal cyst nematode (CCN) is becoming one of the important soil-borne pathogens in wheat (Triticum aestivum L.) monocropping or wheatmaize (Zea mays L.)-wheat cropping systems of central China. Heterodera filipjevi (Madzhidov, 1981) Stelter, 1984 was recently recognized as a causal agent of CCN in China, but little information is available on sources of resistance against this nematode species. The present study was initiated to determine the current status of resistance in wheat cultivars against H. filipjevi and to identify effective resources for improvement of CCN resistance in China. A 3-yr field study of CCN resistance that involved 174 wheat cultivars or wheat-Thinopyrum derivatives was conducted in a wheat field in Xuchang, Henan Province, China, where H. filipjevi 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 field tests. Wheat cultivar Madsen from Washington State was most resistant among the entries tested both in field and under controlled environment. New sources of resistance to H. filipjevi were identified in some wheat-intermediate wheatgrass [Thinopyrum intermedium (Host) Barkworth & D. R. Dewey] and wheat-tall wheatgrass [Thinopyrum ponticum (Podp.) Barkworth & D. R. Dewey] partial amphiploids, which will diversify resistance resources in enhancing resistance of wheat against CCN. [ABSTRACT FROM AUTHOR]