Genetic Analysis of Fusarium Head Blight Resistance in CIMMYT Bread Wheat Line C615 Using Traditional and Conditional QTL Mapping

Abstract

Fusarium head blight (FHB) is a destructive wheat disease present throughout the world, and host resistance is an effective and economical strategy used to control FHB. Lack of adequate resistance resource is still a main bottleneck for FHB genetics and wheat breeding research. The synthetic-derived bread wheat line C615, which does not carry the Fhb1 gene, is a promising source of FHB resistance for breeding. A population of 198 recombinant inbred lines (RILs) produced by crossing C615 with the susceptible cultivar Yangmai 13 was evaluated for FHB response using point and spray inoculations. As the disease phenotype is frequently complicated by other agronomic traits, we used both traditional and multivariate conditional QTL mapping approaches to investigate the genetic relationships (at the individual QTL level) between FHB resistance and plant height (PH), spike compactness (SC), and days to flowering (FD). A linkage map was constructed from 3,901 polymorphic SNP markers, which covered 2,549.2 cM. Traditional and conditional QTL mapping analyses found 13 and 22 QTL for FHB, respectively; 10 were identified by both methods. Among these 10, three QTL from C615 were detected in multiple years; these QTL were located on chromosomes 2AL, 2DS, and 2DL. Conditional QTL mapping analysis indicated that, at the QTL level, SC strongly influenced FHB in point inoculation; whereas PH and SC contributed more to FHB than did FD in spray inoculation. The three stable QTL (QFhbs-jaas.2AL, QFhbp-jaas.2DS, and QFhbp-jaas.2DL) for FHB were partly affected by or were independent of the three agronomic traits. The QTL detected in this study improve our understanding of the genetic relationships between FHB response and related traits at the QTL level and provide useful information for marker-assisted selection for the improvement of FHB resistance in breeding.

Dissecting the Genetic Complexity of Fusarium Crown Rot Resistance in Wheat

“…Annotation of epitasis QTL on chromosomes 5AS, 2AL and 4BS detected proteins that are linked linked to FHB spread, severity and deoxynivalenol production. Moreover, we also found two other proteins associated with epi-QTLs on chromosomes 5AS and 7AL that were previously reported to retain Fhb1 linked to FHB infection and severity 29 .…”

“…Our study revealed that the main effect QTLs lead to increased resistance response under multiple environmental conditions (Tables 2 and 3). We identified two major QTLs on chromosomes 5AS and 7AL that were previously reported to harbor Fhb1 resistance to FHB infection and severity 29 . Although these two QTLs as had been described earlier as major QTLs, our study detected them as only minor QTLs under GR.…”

Genome-wide association mapping revealed syntenic loci QFhb-4AL and QFhb-5DL for Fusarium head blight resistance in common wheat (Triticum aestivum L.)

“…The disease nursery was mist-irrigated for 5 min every 30 min from 7:00 am to 6:00 pm each day to ensure the inoculated spikes fully infected under high humid conditions [50]. The number of infected spikelets and the total number of spikelets of every tagged spike were recorded 25 days after inoculation.…”

Genome-wide association mapping revealed syntenic loci QFhb-4AL and QFhb-5DL for Fusarium head blight resistance in common wheat (Triticum aestivum L.)

“…An association panel comprising 171 wheat cultivars was used for SNP genotyping and two years FHB resistance phenotyping. Among them, three cultivars were derived from Italy, Mexico and Japan, and the other 168 cultivars were collected from 8 provinces at winter wheat region in Northern China and 9 provinces from Southern China ( Table S1) After inoculation, the disease nursery was mist-irrigated for five min every 30 min from 7:00 am to 6:00 pm each day to provide high humid conditions favorable for FHB infection [50]. FHB severities were recorded 25 days after inoculation as the number of symptomatic spikelets per infected spike, and the mean value was used for further analysis.…”