Transfer of Wheat Streak Mosaic Virus Resistance from Agropyron intermedium into Wheat

Abstract

Wheat streak mosaic is a damaging disease of cultivated bread wheat, Triticum aestivum L. em Thell., in many parts of the world. No wheat cultivar has a high level of resistance to WSMV or its vector, the wheat curl mite, Eriophyes tulipae Keifer. Genes conferring resistance to wheat curl mite colonization have been transferred from Aegilops tauschii Coss., Cmc1, and from Agropyron elongatum (Host) Beauv., Cmc2. A gene conditioning resistance to WSMV, Wsm1, was transferred from Agropyron intermedium (Host) Beauv. into common wheat. To broaden the genetic base of wheat, new sources of WSMV resistance are continuously sought. This study reports a new source of WSMV resistance derived from A. intermedium and its transfer into hexaploid wheat. C‐banding analysis was used to cytogenetically identify the A. intermedium chromosomes and chromosome arms in three WSMV resistant wheat‐A. intermedium derivatives, designated as 6957,6961, and 6962. All lines were identified as disomic chromosome addition lines with an A. intermedium chromosome arm in common. Restriction fragment length polymorphism analysis was used to establish homoeology of the A. intermedium chromosome arm carrying the gene or gene complex conditioning resistance to WSMV. The arm belonged to the long arm of the wheat Group 4 chromosomes, and was designated as 4Ai#3L. The added A. intermedium chromosomes present in Lines 6957 and 6961 probably originated from centricfusion. The WSMV resistance of these lines is different from that conditioned by Wsm1 and may have significance in breeding WSMV resistant wheat cultivars.