|LIU, YAN - University Of Arkansas|
|GOAD, DAVID - Washington University|
|CAICEDO, ANA - University Of Massachusetts|
|OLSEN, KENNETH - Washington University|
Submitted to: Plant Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/25/2015
Publication Date: 2/26/2016
Publication URL: http://handle.nal.usda.gov/10113/62002
Citation: Liu, Y., Jia, Y., Gealy, D.R., Goad, D.M., Caicedo, A.L., Olsen, K.M. 2016. Marker development for rice blast resistance gene Pi66(t) and application in USDA rice mini-core collection. Plant Science. 56:1-8. doi: 10.2135/cropsci2015.07.0422.
Interpretive Summary: Molecular markers are useful for the identification of critical genes that control important traits in agricultural crops, and for the utilization of these genes in crop improvement using marker assisted selection (MAS). The improvement of blast disease resistance of rice varieties is a major goal for rice breeders. In earlier work, we mapped the blast resistance (R) gene Pi66(t) to a small region on chromosome 11, and six potential R genes were identified. In the present study, we developed three molecular markers, WRKY41, NBS-LRR-970-1, and NBS-LRR-970-2, for the Pi66(t) R gene in order to help breeders use MAS to improve disease resistance in rice. The validation of two newly developed markers, WRKY41 and NBS-LRR-970-1, suggested they were consistently inherited along with the Pi66(t) R gene in two large recombinant line (RIL) populations that were developed by crossing two U.S. weedy rice strains (PI653435, straw hull awnless weedy rice and, PI653419, black hull awned weedy rice) with an indica rice variety Dee Geo Woo Gen (DGWG). The application of two markers in a diverse USDA-ARS core collection of 217 rice lines indicated that marker NBS-LRR-970-1 was directly linked to the Pi66(t) R gene. Results from this study suggested that the newly developed marker not only can be used to identify resistant lines with Pi66(t) in the RILs, but can also be used in rice germplasm with a broad genetic background using MAS. Taken together, these markers and rice germplasm lines that carry Pi66(t) are essential tools and materials for rice breeders using an MAS approach to crop improvement.
Technical Abstract: Molecular markers are useful for the identification of critical genes controlling agricultural traits of interest in crop germplasm and for the utilization of these genes in crop improvement using marker assisted selection (MAS). The improvement of blast disease resistance of rice varieties is one of the major goals for rice breeders. The blast resistance (R) gene Pi66(t) was previously mapped to a 129 kb genomic region on chromosome 11, where six candidate R genes were predicted. To help rice breeders in resistance MAS breeding, we developed three PCR based molecular markers, WRKY41, NBS-LRR-970-1 and NBS-LRR-970-2, for the Pi66(t) locus. The validation of markers WRKY41 and NBS-LRR-970-1 suggested they co-segregated with the Pi66(t) gene in two recombinant inbred line (RIL) populations. The application of two markers in a USDA-ARS mini-core collection indicated that NBS-LRR-970-1 was a Pi66(t)- linked specific marker. The newly developed marker not only can be used to identify resistant lines with Pi66(t) gene in mapping populations, but also can be used in rice germplasm with a broad genetic background. Taken together, these newly developed markers and newly identified rice germplasm lines carrying the Pi66(t) gene will provide essential tools and materials for rice breeders in MAS breeding.