Quantitative trait loci for broomrape (Orobanche cumana Wallr.) resistance in sunflower

Abstract

Broomrape (Orobanche cumana Wallr.) is a root parasite of sunflower that is regarded as one of the most important constraints of sunflower production in the Mediterranean region. Breeding for resistance is the most effective method of control. P-96 is a sunflower line which shows dominant resistance to broomrape race E and recessive resistance to the very new race F. The objective of this study was to map and characterize quantitative trait loci (QTL) for resistance to race E and to race F of broomrape in P-96. A population from a cross between P-96 and the susceptible line P-21 was phenotyped for broomrape resistance in four experiments, two for race E and two for race F, by measuring different resistance parameters (resistance or susceptibility, number of broomrape per plant, and proportion of resistant plants per F(3) family). This population was also genotyped with microsatellite and RFLP markers. A linkage map comprising 103 marker loci distributed on 17 linkage groups was developed, and composite interval mapping analyses were performed. In total, five QTL ( or1.1, or3.1, or7.1 or13.1 and or13.2) for resistance to race E and six QTL ( or1.1, or4.1, or5.1, or13.1, or13.2 and or16.1) for resistance to race F of broomrape were detected on 7 of the 17 linkage groups. Phenotypic variance for race E resistance was mainly explained by the major QTL or3.1 associated to the resistance or susceptibility character ( R(2)=59%), while race F resistance was explained by QTL with a small to moderate effect ( R(2) from 15.0% to 38.7%), mainly associated with the number of broomrape per plant. Or3.1 was race E-specific, while or1.1, or13.1 and or13.2 of were non-race specific. Or13.1, and or13.2 were stable across the four experiments. Or3.1, and or7.1 were stable over the two race E experiments and or1.1 and or5.1 over the two race F experiments. The results from this study suggest that resistance to broomrape in sunflower is controlled by a combination of qualitative, race-specific resistance affecting the presence or absence of broomrape and a quantitative non-race specific resistance affecting their number.

Screening techniques and sources of resistance against parasitic weeds in grain legumes

“…Combination of different resistance mechanisms into a single cultivar will provide a durable outcome. This can be facilitated by the use of in vitro screening methods that allow dissecting parasitic weed resistance into highly heritable components, together with adoption of marker-assisted selection techniques (Ouedraogo et al, 2002;Román et al, 2002a;Boukar et al, 2004;Pérez-Vich et al, 2004;Valderrama et al, 2004).…”

Genetic diversity and genomic distribution of homologs encoding NBS-LRR disease resistance proteins in sunflower

“…cumana (Wallr.) G. Beck] R-gene on LG 3 (Or 5 ), and a chlorotic mottle virus R-gene on LG 14 (Rcmo-1) (Gentzbittel et al 1998;Bert et al 2001;Gedil et al 2001;Bouzidi et al 2002;Radwan et al 2003Radwan et al , 2004Slabaugh et al 2003;Tang et al 2003;Yu et al 2003;Dußle et al 2004;Pérez-Vich et al 2004;Lenardon et al 2005); the locations of R 1 and R ADV were inferred from linkages of both loci to SCAR markers (Lawson et al 1998) mapped by Yu et al (2003) and cross-referenced in the present study. Other than Rcmo-1 (Lenardon et al 2005), newly identiWed and mapped NBS-LRR loci were linked to each of the previously mapped recognitiondependent R-genes in sunXower (Pl ARG , Pl 8 , R 1 , R ADV , and Or 5 ).…”

Characterization of a novel tomato mutant resistant to the weedy parasites Orobanche and Phelipanche spp.

“…Successful breeding efforts have been made for many crops, such as chickpea (Rubiales et al 2003a), faba bean (Nassib et al 1982;Román et al 2002;Torres et al 2006), pea (Valderrama et al 2004), sunflower (Pérez-Vich et al 2004) and others. One common element in breeding for broomrape resistance is the on-going struggle for genetic broomrape-resistance traits in many crops, such as tomato.…”