REDBIO México 2010

Folio: 28
Tipo de presentación: Cartel
Tema: Mejoramiento Genético Vegetal

INTROGRESSION OF QTLS FOR RESISTANCE TO RICE HOJA BLANCA VIRUS (RHBV) IN ELITE GERMPLASM THROUGH MARKER-ASSISTED BACKCROSSING

L. E. Romero * (1), A. Gutierrez (1), E. Torres (2), S. J. Carabali (1), N. Espinosa (3), C. P. Martinez (1), M. Lorieux (4).
* Autor para correspondencia (Corresponding author) l.e.romero@cgiar.org

1- Agrobiodiversity and Biotechnology, International Center for Tropical Agriculture (CIAT), A.A. 6713, Cali, Colombia ; 2- Fondo Latinoamericano de Arroz de Riego (FLAR), Colombia ; 3- Federación Nacional de Arroceros de Colombia (FEDEARROZ), Colombia; 4- Institut de Recherche pour le Développement (IRD), Plant Genome and Development Laboratory (UMR 5096 CNRS-UPVD-IRD), Montpellier, France

RESUMEN (ABSTRACT)
"Resistance to RHBV is a difficult, laborious and expensive trait to evaluate. Four QTLs conferring resistance to RHBV and its vector Tagosodes orizicolus were used to (i) introgress these QTLs into two susceptible elite materials through Marker-Assisted Backcrossing (MAB) and (ii) fine map the most important QTLs to optimize future marker-based selection strategies. In the present project, molecular markers were used to apply foreground and background selection in backcross populations, targeting resistance RHBV and its vector from the donor cultivars Fd2000 and Fd50. We evaluated resistance to RHBV in a set of ten candidate elite lines from the breeding programs of CIAT and FLAR and then evaluated the DNA polymorphism with 428 simple sequence repeat (SSR) markers distributed along the genome rice. Based on the RHBV score, polymorphism level and other agronomic traits, we selected the two elite lines CT18685-10-3-1-2-2-M and Fd174 as candidate for QTL introgression. F1 plants were generated between these two elite lines and the resistances donors Fd2000 and Fd50 and backcrossed to the recurrent elite lines. In the BC1F1 generation, individuals that possessed the resistance alleles at the QTLs were backcrossed in order to obtain BC2F1 families. The marker screening of these materials is on going and we expect to get BC3 lines by the end of 2010. This MAB approach will grandly speed up and facilitate the identification and selection of elite resistant lines to RHBV and to increase the efficiency of the breeding process. Key words: RHBV, rice, QTLs, resistance, MAB."