Search

Straw is a valuable by-product from cereal production. It is used for agricultural purposes as feed and bedding material for livestock. Additionally, cereal straw is a resource for the production of sustainable biomaterials and bio-energy. To meet the demands of these sectors substantial amounts of straw, with specific properties (e.g. water-holding capacity), are necessary. Since wheat breeding has mainly focused on grain yield rather than on straw yield other cereal species, such as triticale, can be of interest. Therefore, in this research the straw yield and water-holding capacity of four winter wheat and four winter triticale varieties were studied during two growing seasons. For both wheat and triticale there were differences in dry matter yield and percentage dry matter between growing seasons. Furthermore, depending on the growing season, there were significant differences in straw yield between the different wheat and triticale varieties. However, during both growing seasons, the straw yield obtained from the triticale varieties was significantly higher compared to the straw yield obtained from the wheat varieties. Concerning the water-holding capacity, it was concluded that the water absorption potential of triticale straw was higher compared to the water absorption potential of wheat straw. However, only in 2014 a significant difference between wheat and triticale was noted. So, it can be concluded that, besides the known advantages of triticale (performance on marginal soils, disease resistance, low fertilizer input, etc.), this crop has the potential to deliver high yields of high quality straw. [ABSTRACT FROM AUTHOR]

Early blight and brown spot, caused by respectively Alternaria solani and Alternaria alternata, can lead to severe yield losses in potato-growing areas. To date, fungicide application is the most effective measure to control the disease. However, in recent years, a reduced sensitivity towards several active ingredients has been reported. To shed light on this issue, Alternaria isolates were collected from different potato fields in Belgium during two growing seasons. Subsequently, the sensitivity of these isolates was assessed using four widely used fungicides with different modes of action. Demethylation inhibitors, quinone outside inhibitors, a dithiocarbamate and a carboxylic acid amide were included in this study. Although all fungicides reduced spore germination and vegetative growth of Alternaria species to some extent, the interspecies sensitivity was very variable. In general, A. solani was more suppressed by the fungicides compared to A. alternata. The effectiveness of the dithiocarbamate mancozeb was high, whereas the quinone outside inhibitor azoxystrobin showed a limited activity, especially towards A. alternata. Therefore, a subset of the A. alternata and A. solani isolates was tested for the presence of, respectively, the G143A substitution and the F129L substitution in the cytochrome b. The frequency of A. alternata isolates bearing the resistant G143A allele (approximately 65%) was comparable in both sampling years, although sensitivity of isolates decreased during the growing season. This finding points to a shift of the population towards resistant isolates. Both the European genotype I and American genotype II were present in the A. solani population, with genotype I being the most prevalent. None of the genotype I isolates carried the F129L substitution, whereas in 83% of the genotype II isolates this substitution was present. Our results demonstrate for the first time that the Belgian Alternaria population on potato comprises a considerable broad spectrum of isolates with different sensitivity to fungicides. [ABSTRACT FROM AUTHOR]

Models for predicting Fusarium head blight (FHB) and deoxynivalenol (DON) content in wheat provide farmers with a tool for preventing yield loss and mycotoxin contamination. Due to the complex nature of FHB, these models typically take only a subset of explanatory variables as inputs, such as weather conditions during anthesis and, to a lesser extent, field-specific variables and crop characteristics. We present a thorough statistical analysis of a broad spectrum of variables that affect FHB and DON content, using an unique database of field observations covering nine years. This study unveils new variables that play an important role in FHB incidence and DON content. Evidence is brought forward demonstrating the effect of species interactions on DON content and the effect of weather conditions during the vegetative growth stage. Indeed, temperature from November till May was positively correlated with FHB and DON content, whereas relative humidity was negatively correlated with DON content in November and December. In a broader view of the divergent results obtained regarding FHB and DON content in wheat crops, this study underscores that the prediction of FHB and DON content should be seen as two distinct goals. [ABSTRACT FROM AUTHOR]

Molecular markers allow to estimate the pairwise relatedness between the members of a breeding pool when their selection history is no longer available or has become too complex for a classical pedigree analysis. The field of population genetics has several estimation procedures at its disposal, but when the genotyped individuals are highly selected inbred lines, their application is not warranted as the theoretical assumptions on which these estimators were built, usually linkage equilibrium between marker loci or even Hardy–Weinberg equilibrium, are not met. An alternative approach requires the availability of a genotyped reference set of inbred lines, which allows to correct the observed marker similarities for their inherent upward bias when used as a coancestry measure. However, this approach does not guarantee that the resulting coancestry matrix is at least positive semi-definite (psd), a necessary condition for its use as a covariance matrix. In this paper we present the weighted alikeness in state (WAIS) estimator. This marker-based coancestry estimator is compared to several other commonly applied relatedness estimators under realistic hybrid breeding conditions in a number of simulations. We also fit a linear mixed model to phenotypical data from a commercial maize breeding programme and compare the likelihood of the different variance structures. WAIS is shown to be psd which makes it suitable for modelling the covariance between genetic components in linear mixed models involved in breeding value estimation or association studies. Results indicate that it generally produces a low root mean squared error under different breeding circumstances and provides a fit to the data that is comparable to that of several other marker-based alternatives. Recommendations for each of the examined coancestry measures are provided. [ABSTRACT FROM AUTHOR]

Accurate prediction of the phenotypical performance of untested single-cross hybrids allows for a faster genetic progress of the breeding pool at a reduced cost. We propose a prediction method based on ɛ-insensitive support vector machine regression ( ɛ-SVR). A brief overview of the theoretical background of this fairly new technique and the use of specific kernel functions based on commonly applied genetic similarity measures for dominant and co-dominant markers are presented. These different marker types can be integrated into a single regression model by means of simple kernel operations. Field trial data from the grain maize breeding programme of the private company RAGT R2n are used to assess the predictive capabilities of the proposed methodology. Prediction accuracies are compared to those of one of today’s best performing prediction methods based on best linear unbiased prediction. Results on our data indicate that both methods match each other’s prediction accuracies for several combinations of marker types and traits. The ɛ-SVR framework, however, allows for a greater flexibility in combining different kinds of predictor variables. [ABSTRACT FROM AUTHOR]

An abstract of the article "A Field-Specific Web Tool for the Prediction of Fusarium Head Blight and Don Content in Belgium" by K. Audenaert and colleagues is presented.

Biotransformation of mycotoxins in animals comprises phase I and phase II metabolisation reactions. For the trichothecene deoxynivalenol (DON), several phase II biotransformation reactions have been described resulting in DON-glutathiones, DON-glucuronides and DON-sulfates made by glutathione-S-transferases, uridine-diphosphoglucuronyl transferases and sulfotransferases, respectively. These metabolites can be easily excreted and are less toxic than their free compounds. Here, we demonstrate for the first time in the animal kingdom the conversion of DON to DON-3-glucoside (DON-3G) via a model system with plant pathogenic aphids. This phase II biotransformation mechanism has only been reported in plants. As the DON-3G metabolite was less toxic for aphids than DON, this conversion is considered a detoxification reaction. Remarkably, English grain aphids (Sitobion avenae) which co-occur with the DON producer Fusarium graminearum on wheat during the development of fusarium symptoms, tolerate DON much better and convert DON to DON-3G more efficiently than pea aphids (Acyrthosiphon pisum), the latter being known to feed on legumes which are no host for F. graminearum. Using a non-targeted high resolution mass spectrometric approach, we detected DON-diglucosides in aphids probably as a result of sequential glucosylation reactions. Data are discussed in the light of an eventual co-evolutionary adaptation of S. avenae to DON. [ABSTRACT FROM AUTHOR]

An abstract of the article "Impact of Fungicide Timing on the Composition of the Fusarium Head Blight Disease Complex and the Presence of Deoxynivalenol (Don) in Wheat" by K. Audenaert and colleagues is presented.

Background: Gaining insight into crop diversity, both at the genetic and phenotypic levels, is of prime importance for onion breeding with an enhanced yield and quality in combination with improved resistance to biotic and abiotic stresses. In the current study, 192 different onion plants, representing 16 ecotypes, were characterized using ISSR markers., Results: Based on the ISSR marker profile, there was a clear grouping of the plants into 16 different ecotypes. Though the 16 populations originated from the same geographic region in Morocco, a significant genetic diversity was detected. After a genomic characterization, field trials in three different environments in Morocco were laid out. The phenotypic characterization showed that there were always significant differences between ecotypes, and for most traits, there was also a significant environmental effect and a significant interaction between environment and ecotype. The broad-sense heritability (H 2 ) for the phenotypic traits associated with color (L*, a*, and b*) was the largest (84.2%, 80.6%, 79.2%), demonstrating that color is conditioned primarily by genetic factors. In contrast, the H 2 for yield was the lowest (41.8%), indicating that the environment has a substantial effect on yield. In addition, there was a significant association between the presence/absence of certain bands and various phenotypic traits., Conclusion: ISSR markers are a powerful tool in distinguishing onion ecotypes. In addition, significant associations between marker scores and phenotypic traits could be detected, representing particular importance for future breeding programs., (© 2022. The Author(s).)