Ana Badea

Development and assessment of DArT markers in triticale

Triticale (X Triticosecale Wittm.) is a hybrid derived by crossing wheat (Triticum sp.) and rye (Secale sp.). Till date, only a limited number of simple sequence repeat (SSRs) markers have been used in triticale molecular analyses and there is a need to identify dedicated high-throughput molecular markers to better exploit this crop. The objective of this study was to develop and evaluate diversity arrays technology (DArT) markers in triticale. DArT marker technology offers a high level of multiplexing. Development of new markers from triticale accessions was combined with mining the large collection of previously developed markers in rye and wheat. Three genotyping arrays were used to analyze a collection of 144 triticale accessions. The polymorphism level ranged from 8.6 to 23.8% for wheat and rye DArT markers, respectively. Among the polymorphic markers, rye markers were the most abundant (3,109) followed by wheat (2,214) and triticale (719). The mean polymorphism information content values were 0.34 for rye DArT markers and 0.37 for those from triticale and wheat. High correlation was observed between similarity matrices derived from rye, triticale, wheat and combined marker sets, as well as for the cophenetic values matrices. Cluster analysis revealed genetic relationships among the accessions consistent with the agronomic and pedigree information available. The newly developed triticale DArT markers as well as those originated from rye and wheat provide high quality markers that can be used for diversity analyses and might be exploited in a range of molecular breeding and genomics applications in triticale.

Phenotypic and marker-assisted evaluation of spring and winter wheat germplasm for resistance to fusarium head blight

Fusarium head blight (FHB) caused by Fusarium species, is among the most devastating wheat diseases, causing losses in numerous sectors of the grain industry through yield and quality reduction, and the accumulation of poisonous mycotoxins. A germplasm collection of spring and winter wheat, including nine reference cultivars, was tested for Type II FHB resistance and deoxynivalenol (DON) content. Genetic diversity was evaluated on the basis of Simple Sequence Repeat (SSR) markers linked to FHB resistance quantitative trait loci (QTLs) and Diversity Arrays Technology (DArT) markers. The allele size of the SSR markers linked to FHB resistance QTLs from known resistance sources was compared to a germplasm collection to determine the presence of these QTLs and to identify potentially novel sources of resistance. Forty-two accessions were identified as resistant or moderately resistant to Fusarium spread, and two also had very low DON concentrations. Genetic relationships among wheat accessions were generally consistent with their geographic distribution and pedigree. SSR analysis revealed that several resistant accessions carried up to four of the tested QTLs. Resistant and moderately resistant lines without any known QTLs are considered to be novel sources of resistance that could be used for further genetic studies.

Antimicrobial peptides expressed in wheat reduce susceptibility to Fusarium head blight and powdery mildew

Badea, A., Eudes, F., Laroche, A., Graf, R., Doshi, K., Amundsen, E., Nilsson, D. and Puchalski, B. 2013. Antimicrobial peptides expressed in wheat reduce susceptibility to Fusarium head blight and powdery mildew. Can. J. Plant Sci. 93: 199-208. Antimicrobial peptides (AMPs) have a broad spectrum of action against bacteria, fungi and viruses, which makes them attractive for building plant defense against a diversity of pathogens. Peptides MsrA2 and 10R were cloned in three genetic constructs for tissue-specific expressions in wheat, using either Lem1, GstA1WIR1a, or Ltp6 and LTP6 signal peptide targeting the lemma/palea, leaves and spikes, epicarp and endomembrane system, respectively. The minimal cassettes for these three genetic constructs and for Pat marker construct were co-delivered in immature wheat scutella using biolistics, and green plantlets were regenerated in presence of 5 mg L-1 glufosinate. Molecular screening confirmed one regenerated plant carried and expressed all transgenes (AMP+): one copy of 10R driven by Ltp6 promoter, one copy of msrA2 driven by GstA1Wir1a and two copies of msrA2 driven by Lem1. Its offspring and T3 generation were challenged with Fusarium graminearum and Blumeria graminis in a contained environment. A reduction of 50% in Fusarium head blight susceptibility was observed in T1, and was inherited through T3 generation. The latter, also presented a 53% reduction in Fusarium damaged kernels and 62% reduction in deoxynivalenol accumulation compared with wild cv. Fielder and sister lines AMP-. MsrA2 and 10R producing T3 lines showed an average significant reduction of 59% in powdery mildew susceptibility compared with cv. Fielder. Synthetic MsrA2 and 10R peptides were effective as in vivo antifungal peptides in wheat. The expression of antimicrobial peptides in plant cells or tissues may have great potential to limit pathogen infection or growth protecting wheat against a diversity of fungal diseases.

Protein can be taken up by damaged wheat roots and transported to the stem

Proteins of animal origin can represent a portion of the overall nitrogen (N) pool in the soil environment and there is a possibility that plants may utilize animal proteins as a N source. Using wheat (Triticum aestivum L.) we investigated if the model protein, ovalbumin was taken up into the roots and transported within the plant. In roots, ovalbumin was associated with the epidermis when no root damage was evident, but with minor root damage, it was present in intercellular spaces throughout the cortex and at the endodermis. Ovalbumin was only found in the stem when minor damage to the root system was evident. Suspension cultures of wheat protoplasts revealed that ovalbumin was not assimilated into individual plant cells. Our results suggest that ovalbumin uptake and subsequent movement in wheat is possible only after root damage has occurred. Apoplastic movement may enable animal protein to enter plant tissues above the soil level where they could be consumed by grazers.

In vitro evaluation of antimicrobial peptides against Fusarium species

The in vitro activity of five antimicrobial peptides was evaluated against several Fusarium species that affect wheat in Canada. Among the peptides tested (10R, 11R, BMAP-18, MsrA2 and MsrA3) 10R was most effective against conidial germination, whereas MsrA2 showed activity against mycelial growth. Antimicrobial peptides 10R and MsrA2 were identified as potential candidates for engineering resistance against common species causing fusarium head blight in wheat. Key words: Antimicrobial peptides, fusarium head blight, conidia, mycelia

Characterization of the Genomes and the Transcriptome of Triticale

In this review, we describe how different tools and approaches help to identify changes in the genome and the transcriptome of triticale toward a better understanding on how gene interactions are regulated in this man-made, intergeneric species. The improvement in cytogenetic, genomic, and transcriptomic tools for characterization of triticale at a molecular level has provided many new ways to better and to more efficiently understand triticale. Although recent initiatives have targeted a better utilization of triticale in bioenergetics, biomaterials, and animal feed, it is possible that triticale’s importance could increase as a food source for humans in the near future.

AAC Connect barley

Abstract: AAC Connect is a hulled two-row spring malting barley (Hordeum vulgare L.) cultivar widely adapted to western Canada. Developed from the cross TR04282/BM9831D-229 made in 2004, AAC Connect was evaluated in the Western Cooperative Two-Row Barley Registration Test (2012–2013) and the Collaborative Malting Barley Trials (2013–2014) conducted by the malting and brewing industry before being registered in 2016. AAC Connect has a desirable combination of agronomic, malting quality, and disease-resistance traits including lower deoxynivalenol accumulation.

Efficiency of protein as a nitrogen source for wheat and morphological changes in roots exposed to high protein concentrations

Rasmussen, J., Gilroyed, B. H., Reuter, T., Badea, A., Eudes, F., Graf, R., Laroche, A., Kav, N. N. V. and McAllister, T. A. 2014. Efficiency of protein as a nitrogen source for wheat and morphological changes in roots exposed to high protein concentrations. Can. J. Plant Sci. 94: 603-613. Proteins of animal origin can enter the environment through application of agricultural by-products to arable or pastured land. In this study, wheat (Triticum aestivum cv. AC Andrew) was exposed to treatments with nitrogen (N) supplied as animal protein (bovine serum albumin; BSA), inorganic N or a combination of these sources at different iso-nitrogenous concentrations. Plant growth was assessed by monitoring both wet and dry mass of shoots and data showed that protein treatments did not differ (P>0.05) from controls lacking N. Analysis of N also showed that plants supplied with protein N displayed lower N (1.2-2.4%) concentration as compared with those supplied with inorganic N (up to 12.4%) with N remaining <2.4% even when the supply of protein was increased. Root morphology was altered in plants exposed to protein N concentrations >71 mM, with the development of knob-like outgrowths with unknown function or significance. This study provides evidence that wheat plantlets grown under sterile conditions are unable to utilize BSA as efficiently as NH4NO3 as a N source, but their roots exhibit a morphological response to protein.