Browsing by Subject "Fusarium Head Blight Resistance"

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    Genome-wide association mapping of fusarium head blight resistance and agromorphological traits in barley landraces from Ethiopia and Eritrea
    (Crop Science, 2015-06-12) Steffenson, Brian; Mamo, Bullo Erena
    Fusarium head blight (FHB), caused primarily by Fusarium graminearum, is an important disease of barley (Hordeum vulgare L.), and other cereals. In barley, the genetic basis of FHB resistance has been intensively studied through linkage mapping that identified several quantitative trait loci (QTL). However, our understanding and application of these QTL in breeding is still limited due to the complex nature and low-to-moderate heritability of FHB resistance. Previous studies used either breeding lines, unimproved varieties, or germplasm selections. Here, we used association mapping in barley landraces to identify QTL associated with FHB severity, deoxynivalenol (DON) concentration and correlated agromorphological traits. Diverse barley landraces (n = 298) from Ethiopia and Eritrea were evaluated for the traits under field conditions for 2 yr (2011–2012) in Crookston, MN, and genotyped with 7842 single nucleotide polymorphism (SNP) markers. Association mapping analysis using a mixed model corrected for pairwise relatedness between individuals identified one common resistance QTL on barley chromosome 2HL significantly associated with both FHB severity and DON concentration and another one on 4HL associated with DON concentration. The QTL identified on 2HL is associated with the row-type locus Vrs1. Both of these QTL were not significantly associated with heading date or plant height unlike other QTL reported in previous studies. Thus, the resistant accessions carrying these QTL may be used in breeding programs without the confounding effects from these agromorphological traits. Importantly, these QTL could be new alleles preserved in this unique germplasm, and the linked SNP markers found may be useful in marker-assisted introgression of resistance.
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    Identification of QTLs Associated with Fusarium Head Blight Resistance in Barley Accession CIho 4196
    (Crop Science, 2006) Steffenson, Brian; Horsley, R.D.; Schmierer, D.; Maier, C.; Kudrna, D.; Urrea, C.A.; Schwarz, P.B.; Franckowiak, J.D.; Green, M.J.; Zhang, B.; Kleinhofs, A.
    Fusarium head blight (FHB), incited by Fusarium graminearum Schwabe [teleomorph Gibberella zea (Schwein)], reduces quality of harvested barley (Hordeum vulgare L.) because of blighted kernels and the presence of deoxynivalenol (DON), a mycotoxin produced by the pathogen. CIho 4196, a two-rowed type, is one of the most resistant accessions known in barley; however, it possesses many undesirable agronomic traits. To better understand the genetics of reduced FHB severity and DON accumulation conferred by CIho 4196, a genetic map was generated using a population of recombinant inbred lines derived from a cross between Foster (a six-rowed malting cultivar) and CIho 4196. Quantitative trait loci (QTL) analyses were performed using data obtained from 10 field environments. The possible associations of resistance QTLs and various agronomic and morphological traits in barley also were investigated. The centromeric region of chromosome 2H flanked by the markers ABG461C and MWG882A (bins 6-10) likely (P < 0.001) contains two QTLs contributing to lower FHB severity and plant height, and one QTL each for DON accumulation, days to heading, and rachis node number. The QTL for low FHB severity in the bin 8 region explained from 3 to 9% of the variation, while the QTL in the bin 10 region explained from 17 to 60% of the variation. A QTL for DON accumulation that explained 9 to 14% of the variation was found in the bin 2 region of chromosome 4H. This may represent a new QTL not present in other FHB resistant sources. Resistance QTLs in the bin 8 region and bin 10 region of chromosome 2HL were provisionally designated Qrgz-2H-8 and Qrgz-2H-10, respectively. The QTL for DON accumulation in chromosome 4H was provisionally named QDON-4H-2.
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    Registration of 6NDRFG-1 six-rowed barley germplasm line with partial Fusarium head blight resistance
    (Crop Science, 2002) Steffenson, Brian; Urrea, C.A.; Horsley, R.D.; Frankowiak, J.D.