Knowledge of the extent of phenotypic variability, genetic diversity and the realized breeding progress is central for the optimum design of breeding programmes, but little information is available for triticale (× Triticosecale Wittmack). In this study, a collection of 885 diverse European triticale lines was evaluated in multilocation field trials in 2 years. We observed significant genotypic variances and high heritabilities for several agronomic and morphological traits and significant correlations among different traits including grain yield. Based on a subset of the population of 121 varieties registered in Europe between 1983 and 2014, we observed a substantial breeding progress for grain yield with a significant rate of increase of 53 kg/ha or 0.67% per year. All lines were genotyped by a genotyping‐by‐sequencing approach yielding 58 888 polymorphic markers. Our analyses revealed the absence of major population structure but a certain grouping of lines according to their origin. Taken together, our results on triticale germplasm and its breeding history provide important information for breeding programmes and future selection gain in this crop.

Genome-wide association mapping of resistance against the novel, aggressive 'Warrior' race of yellow rust in triticale revealed a genetic architecture with some medium-effect QTL and a quantitative component, which in combination confer high levels of resistance on both leaves and ears. Yellow rust is an important destructive fungal disease in small grain cereals and the exotic 'Warrior' race has recently conquered Europe. The aim of this study was to investigate the genetic architecture of yellow rust resistance in hexaploid winter triticale as the basis for a successful resistance breeding. To this end, a diverse panel of 919 genotypes was evaluated for yellow rust infection on leaves and ears in multi-location field trials and genotyped by genotyping-by-sequencing as well as for known Yr resistance loci. Genome-wide association mapping identified ten quantitative trait loci (QTL) for yellow rust resistance on the leaves and seven of these also for ear resistance. The total genotypic variance explained by the QTL amounted to 44.0% for leaf and 26.0% for ear resistance. The same three medium-effect QTL were identified for both traits on chromosomes 1B, 2B, and 7B. Interestingly, plants pyramiding the resistance allele of all three medium-effect QTL were generally most resistant, but constitute less than 5% of the investigated triticale breeding material. Nevertheless, a genome-wide prediction yielded a higher predictive ability than prediction based on these three QTL. Taken together, our results show that yellow rust resistance in winter triticale is genetically complex, including both medium-effect QTL as well as a quantitative resistance component. Resistance to the novel 'Warrior' race of this fungal pathogen is consequently best achieved by recurrent selection in the field based on identified resistant lines and can potentially be assisted by genomic approaches.

Grain yield and its component trait thousand kernel weight are important traits in triticale breeding programmes. Here, we used a large mapping population of 647 doubled haploid lines derived from four families to dissect the genetic architecture underlying grain yield and thousand kernel weight by multiple‐line cross QTL mapping. We identified 3 QTL for grain yield and 13 for thousand kernel weight which cross‐validated explained 5.2% and 48.2% of the genotypic variance, respectively. Both traits showed a positive phenotypic correlation, and we found two QTL overlapping between them. Full two‐dimensional epistasis scans revealed epistatic QTL for both traits, suggesting that epistatic interactions contribute to their genetic architecture. Based on QTL identified in our results, we conclude that the potential for marker‐assisted selection is limited for grain yield but more promising for thousand kernel weight.

Triticale (×Triticosecale Wittmack) holds great potential as a source for biomass production for industrial applications in Central Europe and hybrid breeding in particular appears promising owing to the higher vigour of hybrids compared to lines. In this study, a set of 178 winter triticale genotypes, including 91 hybrids, their 10 male and 23 female parental lines, as well as 54 varieties were evaluated for biomass yield and other agronomically relevant traits in 2 years at five locations in Germany. We observed a large variation of dry biomass yield as well as significant genotypic variances and high heritabilities for all traits. For the hybrids, a moderate correlation was observed between biomass and plant height and between biomass and grain yield. Mid‐parent heterosis of biomass yield ranged from −13.6 to 16.5% with an average of 4.8%, and the maximum commercial heterosis was 9.1%. Taken together, our results illustrate the potential of hybrid breeding of triticale for biomass yield to diversify our portfolio of crops for biomass production.

Ornamental plants are appreciated by humans for their colorfulness, beauty, abundant flowering and long blooming periods. Many ornamental plants can also constitute an additional foraging resource for flower-visiting insects. However, the ability of the popular ornamental plant Calibrachoa to support urban insect communities is not well documented. In this study, 20 different Calibrachoa cultivars were selected and tested in regard to their insect friendliness based on standardized observations (I) in flight tents using the large earth bumble bee Bombus terrestris as a model species and (II) in open field trials. To investigate what floral characteristics might constitute attractiveness to bumble bees, various floral traits were recorded and compared across all tested Calibrachoa cultivars. Over a two-year period, a total of 6,327 foraging bumble bees were recorded in the tent observations. In the open field observations, we counted 4,188 flower-visiting insects. Our results revealed that (I) all Calibrachoa cultivars were visited by insects for foraging, (II) the number of insect visitors varied significantly among the 20 tested cultivars and (III) the cultivars displayed different floral traits. For the morphometric floral traits and the aroma profiles of Calibrachoa, only the mean nectar quantity and a few identified compounds could be correlated with attractiveness to the model species B. terrestris. We also found that the petal color of the tested cultivars had a significant impact on the number of visitors. Therefore, B. terrestris clearly preferred red or blue Calibrachoa cultivars over those with other petal colors. However, as the cultivar preferences in the different insect groups differed, it is highly recommended to use various cultivars in urban plantings. Nevertheless, efforts must be made to explain what additional floral traits make Calibrachoa and other ornamental plants generally attractive to flower visitors. This information can then be used for breeding purposes to increase the insect friendliness of ornamental plants.