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Like other small grain cereals, triticale (× Triticosecale Wittmack) is also affected by Fusarium head blight (FHB) which is a serious plant disease leading to yield losses and to a contamination of feed and food by harmful mycotoxins. Use of resistant varieties is the most effective way to manage FHB infections. More recently, commercial hybrid breeding in autogamous cereals has received increased interest. Therefore, we built a bridge between hybrid and resistance breeding and conducted a multi-environmental field trial using deliberate inoculation with Fusarium culmorum to: (i) evaluate different hybrid prediction approaches based on phenotypic and/or genomic data; (ii) compare the effect of cytoplasmic male sterility (CMS) inducing cytoplasm and normal (N) cytoplasm on FHB resistance. We evaluated 226 single cross hybrids, their paternal and maternal lines in both CMS- and N-cytoplasm. Our analysis revealed a large genetic variation for FHB resistance. Single cross hybrids tended to be more resistant than their parental lines. We observed a close association between N-lines and CMS-lines for FHB resistance. We found a predominance of σ over σ for FHB resistance. Correlation between the sum of general combining ability (GCA) effects and hybrid performance was high for FHB resistance. Mid-parent performance served as a moderate indicator for FHB resistance of single crosses. Best linear unbiased prediction of hybrid performance based on relatedness between tested and untested genotypes estimated by marker data showed great potential for hybrid prediction when no reliable per se information or GCA estimates are available. [ABSTRACT FROM AUTHOR]

Key message: QTL mapping in multiple families identifies trait-specific and pleiotropic QTL for biomass yield and plant height in triticale. Abstract: Triticale shows a broad genetic variation for biomass yield which is of interest for a range of purposes, including bioenergy. Plant height is a major contributor to biomass yield and in this study, we investigated the genetic architecture underlying biomass yield and plant height by multiple-line cross QTL mapping. We employed 647 doubled haploid lines from four mapping populations that have been evaluated in four environments and genotyped with 1710 DArT markers. Twelve QTL were identified for plant height and nine for biomass yield which cross-validated explained 59.6 and 38.2 % of the genotypic variance, respectively. A major QTL for both traits was identified on chromosome 5R which likely corresponds to the dominant dwarfing gene Ddw1. In addition, we detected epistatic QTL for plant height and biomass yield which, however, contributed only little to the genetic architecture of the traits. In conclusion, our results demonstrate the potential of genomic approaches for a knowledge-based improvement of biomass yield in triticale. [ABSTRACT FROM AUTHOR]

Key Message: QTL mapping in multiple families identifies trait-specific and pleiotropic QTL for biomass yield and plant height in triticale. Triticale shows a broad genetic variation for biomass yield which is of interest for a range of purposes, including bioenergy. Plant height is a major contributor to biomass yield and in this study, we investigated the genetic architecture underlying biomass yield and plant height by multiple-line cross QTL mapping. We employed 647 doubled haploid lines from four mapping populations that have been evaluated in four environments and genotyped with 1710 DArT markers. Twelve QTL were identified for plant height and nine for biomass yield which cross-validated explained 59.6 and 38.2 % of the genotypic variance, respectively. A major QTL for both traits was identified on chromosome 5R which likely corresponds to the dominant dwarfing gene Ddw1. In addition, we detected epistatic QTL for plant height and biomass yield which, however, contributed only little to the genetic architecture of the traits. In conclusion, our results demonstrate the potential of genomic approaches for a knowledge-based improvement of biomass yield in triticale.