Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/20/2002
Publication Date: 8/1/2002
Citation: MALIK,R., BROWN GUEDIRA,G.L., SMITH,C.M., HARVEY,T.L., GILL,B.S., GENETIC MAPPING OF WHEAT CURL MITE RESISTANCE GENES CMC3 AND CMC4 IN COMMON WHEAT, CROP SCIENCE, 2002. 43:644-655. Interpretive Summary: The wheat curl mite (WCM), Aceria tosichella Keifer, is a serious pest of wheat the Great Plains of North America. Genetic resistance to this pest is the most effective means of control. In this study, we evaluated three genes for wheat curl mite resistance that were transferred to from rye (Cmc3) and from the wild wheat relative Ae. tauschii (Cmc1 and Cmc4). Our analyses determined that these genes are different based on reaction to different strains of the wheat curl mite, segregation in allelism crosses, and genetic map location. The gene Cmc4 in wheat line KS96WGRC40 that was developed in our laboratory is the most effective resistance gene currently available. New DNA markers were identified that can be used to identify plants having the Cmc3 gene from rye (SCM09) and the Cmc4 gene in KS96WGRC40 (Xgdm141 and XksuG8). The linked markers may be used in wheat breeding programs for selection of lines resistant to WCM and for resistance gene pyramiding.
Technical Abstract: The wheat curl mite (WCM), Aceria tosichella Keifer, is a serious pest of wheat (Triticum aestivum L.) in North America. The objectives of this study were to (1) clarify the inheritance and location of a WCM resistance gene in wheat cultivar TAM 107, (2) determine the genetic relationship of a WCM resistance gene transferred from Ae. tauschii to the wheat germplasm KS96WGRC40 with the Cmc1 gene previously tranferred from this species and (3) determine the chromosome and linkage map location of the WCM resistance gene in KS96WGRC40. The WCM resistance gene in TAM 107, designated Cmc3, is present on wheat-rye translocation T1AL·1RS and is no longer effective against all WCM populations. Microsatellite analyses of a segregating F2 population revealed that the rye-specific marker SCM09 can be used to select wheat lines carrying the 1RS segment and Cmc3. WCM testing of F2 and F3 populations from an allelism cross indicated that the Ae. tauschii-derived WCM resistance gene in KS96WGRC40, designated Cmc4, was inherited as a single dominant gene that segregated independently of Cmc1. Molecular and cytogenetic analyses located Cmc4 on chromosome 6DS distal to the centromere flanked by markers Xgdm141 (4.1cM) and XksuG8 (6.4cM). Only a small segment of chromosome 6D of Ae. tauschii containing Cmc4 was transferred to KS96WGRC40. The linked markers may be used in wheat breeding programs for the selection of lines resistant to WCM and for gene pyramiding.