Variation of specific morphological traits and ploidy level of five "aegilops" l. species in Morocco

Variation of specific morphological traits and ploidy level of five Aegilops L. species in Morocco.The genus Aegilops L. represents an important natural source of useful genes for wheat breeding, with particular emphasis on biotic and abiotic stress resistance. For successful crosses, the primarily step is to select appropriate Aegilops accessions. In this paper, we studied five Moroccan species of an Aegilops collection on the basis of spike structure and chromosome number. Twenty-eight specific morphological characters were used to differentiate the species. Statistical analyses, in particular the DFA, allowed the characterization of the genetic variability of the species; the two first standardized axes explained 96,2% of the total variability and 100% of the entities were classified within their own group. In addition, the dendrogram constructed using morphological data reveals a significant variability within and between species. Cytogenetic study revealed four species, A. geniculata Roth, A. triuncialis L., A. ventricosa Tausch and A. peregrina Maire & Weiller, to be tetraploid. However, A. neglecta Req. ex. Bertol., where only two accessions are represented in the collection, revealed to be hexaploid, and can then be classified as A. neglecta subsp. recta Chennav

Interspecific cross between Durum Wheat and Aegilops geniculata to transfer resistance to Hessian fly (Mayetiola destructor Say.)

Interspecific cross between Durum Wheat and Aegilops geniculata to transfer resistance to Hessian fly (Mayetiola destructor Say.). Interspecific crosses between durum wheat (Triticum durum) and accessions of Aegilops geniculata were initiated the first year of the present program. Only those accessions that were resistant to Hessian fly (Mayetiola destructor Say.) were used with the objective to transfer the resistance to wheat. Embryo rescue of immature hybrid seeds was necessary. Two hybrids between T. durum and A. geniculata were produced and planted in the field the second year. They presented intermediate traits between their two parents and produced a progeny after selfing or backcrossing. Meiotic analysis of the pollen mother cells showed low pairing between parental chromosomes in the hybrids

Peroxidase expression in a cereal cyst nematode (Heterodera avenae) resistant hexaploid wheat line.

The incompatible interaction between plant and pathogen is often determined by the hypersensitive reaction (HR). This response is associated with accumulation of reactive oxygen species (ROS), which results in adverse growth conditions for pathogens. Two major mechanisms involving either NADPH oxidases or peroxidases have been proposed for generation of ROS. Peroxidases (PER, EC 1.11.1.7), present in all land plants, are members of a large multigenic family with high number of isoforms involved in a broad range of physiological processes. PER genes, which are expressed in nematode feeding sites, have been identified in several plant species (Zacheo et al. 1997). A strong correlation between HR and PER activities at four and seven days post nematode infection, was detected in roots of wheat lines carrying Cre2, Cre5 (from Ae. ventricosa) or Cre7 (from Ae. triuncialis) Heterodera avenae resistance genes (Andrés et al. 2001; Montes et al. 2003, 2004). We have studied changes in root of peroxidase mRNAs levels after infection by H. avenae of a wheat/Ae. ven¬tricosa introgression line (H-93-8) carrying Cre2 (Delibes et al. 1993). We also report and classify the predicted protein sequences derived from complete peroxidase transcripts

Cytomolecular identification of individual wheat-wheat chromosome arm associations in wheat-rye hybrids

Chromosome pairing in the meiotic metaphase I of wheatrye hybrids has been characterized by sequential genomic and fluorescent in situ hybridization allowing not only the discrimination of wheat and rye chromosomes, but also the identification of the individual wheat and rye chromosome arms involved in the chromosome associations. The majority of associations (93.8%) were observed between the wheat chromosomes. The largest number of wheat-wheat chromosome associations (53%) was detected between the A and D genomes, while the frequency of B-D and A-B associations was significantly lower (32 and 8%, respectively). Among the A-D chromosome associations, pairing between the 3AL and 3DL arms was observed with the highest frequency, while the most frequent of all the chromosome associations (0.113/ cell) was found to be the 3DS-3BS. Differences in the pairing frequency of the individual chromosome arms of wheat-rye hybrids have been discussed in relation to the homoeologous relationships between the constituent genomes of hexaploid wheat

Overview on the current organizational models for cultivar testing for Organic Agriculture over some EU countries.

Variety trials are an important way to evaluate the suitability of existing varieties (conventional, organic, landraces, heirloom, etc.) for organic farming, and are a necessary step in plant breeding and variety registration. However, it is essential that beside on-stations trials, varieties are also tested on-farm in different climatic regions as this gives more accurate and realistic variety performance assessment (Lyon et. al. 2019). Varieties of different crop species are in service to various stakeholders. Thus, their involvement may play an important role in variety trials. They could contribute, with knowledge, seed material in kind or financial support, to build cost-effective variety testing models also for crops that are not grown on a large scale and have small market share. In the report evaluation of different organic variety trials for pre- and post-registration as well as VCU across 15 EU countries (for arable incl. forage, vegetable and fruit crops) is presented through 4 main criteria (trial setup, organizational model, dissemination of results and financial model). Through the range of organizational models of variety trials there were some that were mainly governmentally supported and involving researchers, others that have strong engagement of breeders and seed companies, or are done within seed companies, and some that are running just if project financing is available or some that are mainly established by farmers and done on voluntary basis. Organizational models of variety trials have quite complex nature and therefore, it is not possible to give a general recipe for establishing successful variety trials network. Institutes or initiatives organize trials depending on different socio-economic conditions, such as financial possibilities, economic importance of the crop in the country, chain actors’ engagements, organic sector development, existing trial infrastructure etc. In the report, SWOT analysis of different organizational model groups give better understanding of pros and cons of the different systems and show necessary infrastructure for different models. These analyses will serve as a base for development of guidelines for on-farm trials models that are low budget, with alternative financing and new infrastructures

Effects of introgressed 4Nv Aegilops ventricosa chromosome on yield and yield components in bread wheat.

Effects of introgressed 4Nv Aegilops ventricosa chromosome on yield and yield components in bread whea

Heterogeneity of wheat endosperm proteolipids (CM proteins)

Proteins extracted with CHCl3-MeOH from wheat endosperm have been fractionated by Sephadex G-100 and the 15 000–20 000 MW range fraction, designated CM protein, has been examined by combined electrofocusing (pH range 5–8) and electrophoresis (pH 3.2) and the heterogeneity of the electrophoretic components has been ascertained. It has been shown by joint mapping and by sequential extraction that CM proteins are extracted by 70% EtOH but not by H2O, although they can be made water-soluble after dialysis against an acid buffer, pH 3.2, 3 M urea, without losing their solubility in CHCl3-MeOH mixtures. It is concluded that CM proteins fit the definition of a Folch—Lees proteolipid. The Triticum aestivum (genomes ABD) map can be reconstructed by mixing T. durum (AB) and Aegilops squarrosa (D). The low intragenomic variability of CM protein is confirmed

Celiac Immunogenic Potential of α-Gliadin Epitope Variants from Triticum and Aegilops Species

The high global demand of wheat and its subsequent consumption arise from the physicochemical properties of bread dough and its contribution to the protein intake in the human diet. Gluten is the main structural complex of wheat proteins and subjects affected by celiac disease (CD) cannot tolerate gluten protein. Within gluten proteins, α-gliadins constitute the most immunogenic fraction since they contain the main T-cell stimulating epitopes (DQ2.5-glia-α1, DQ2.5-glia-α2, and DQ2.5-glia-α3). In this work, the celiac immunotoxic potential of α-gliadins was studied within Triticeae: diploid, tetraploid, and hexaploid species. The abundance and immunostimulatory capacity of CD canonical epitopes and variants (with one or two mismatches) in all α-gliadin sequences were determined. The results showed that the canonical epitopes DQ2.5-glia-α1 and DQ2.5-glia-α3 were more frequent than DQ2.5-glia-α2. A higher abundance of canonical DQ2.5-glia-α1 epitope was found to be associated with genomes of the BBAADD, AA, and DD types; however, the abundance of DQ2.5-glia-α3 epitope variants was very high in BBAADD and BBAA wheat despite their low abundance in the canonical epitope. The most abundant substitution was that of proline to serine, which was disposed mainly on the three canonical DQ2.5 domains on position 8. Interestingly, our results demonstrated that the natural introduction of Q to H at any position eliminates the toxicity of the three T-cell epitopes in the α-gliadins. The results provided a rational approach for the introduction of natural amino acid substitutions to eliminate the toxicity of three T-cell epitopes, while maintaining the technological properties of commercial wheats

Biochemical evidence of gene transfer from the Mv genome of Aegilops ventricosa to hexaploid wheat

Endosperm protein and isozyme patterns of Unes derived from the ovoss [Tritioum turgidum (AABB) x Aegilops ventrioosa (DDMVMV)] x T_. aes tivum (AABBDD) were studied. Five bioohemioal oharaoters pvesent in Ae_. ventrioosa (DDM°M°), Ae_. oomosa (MU) and Ae_. uniaris tata (MUMU) , but absent from Ae. squarrosa (DD)t T_. aes tivum (AABBDD) and T_. turgidum (AABB) were investigated. Three of these were identified in several Unes3 indioating gene transfer from the M° genome of Ae. ventrioosa into hexaploid wheat. The wide distribution of one of the markers (CM-4) suggests its previous transfer to the D genome of Ae. ventrioosa