Analysis of DNA methylation patterns associated with drought stress response in faba bean (Vicia faba L.) using methylation-sensitive amplification polymorphism (MSAP).Environmental and Experimental Botany http://dx.

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The genetic diversity of 21 faba bean populations was examined using morphological and molecular markers. DNA was extracted from 189 individuals and 8 microsatellite markers were genotyped individually in these 21 populations. A total of 53 alleles were obtained in all populations, with an average of 6.62 alleles per locus. The expected and observed heterozygosity was 0.38 and 0.62 respectively. The average polymorphism index content of SSR markers was 0.61, ranging from 0.31 to 0.81. The unweighted pair group method with arithmetic mean dendrogram clustered all the populations into two groups, each for them subdivided into 3 sub-groups according to geographical origin. Morphological variation showed that the populations were not grouped according to their geographical origin. Therefore, patterns of differentiation of morphological traits did not coincide with molecular differentiation, indicating that morphological variation does not reflect genetic subdivision in studied faba bean populations. Analysis of molecular variance revealed high levels of genetic variation (83%) within population and provides a good base for designing genetic improvement programs. The result of Principal Component Analysis (PCA) revealed that three dimensional principal components (PC1, PC2 and PC3) contributed 40.56% of the total variability and accounted with values of 20.64, 11.22 and 8.70%, respectively. Cluster analysis based on PCA indicated three separate groups of populations. The genetic relationships found between the 21 populations samples were the same in both the PCA and STRUCTURE analysis which support the results observed. These data may serve as a foundation for the development of faba bean breeding programs.

ABSTRACT. Genetic diversity within Vicia faba L. is key to the genetic improvement of this important species. In this study, morphological traits and RAPD molecular markers were used to assess the levels of polymorphism across 12 Tunisian populations, three major and nine minor from different locations. Analysis of morphological traits indicated that the three major populations showed significant differences and the nine minor populations exhibited considerable variation for most traits. The grain yield of the Alia population could be increased by inoculation. Of the seven primers tested, it was clear that the Cs12 primer would be recommend for genetic diversity analysis of V. faba. Within population genetic diversity exhibited 94% of total diversity. Intra-population genetic diversity (H S ) was 0.16, which was clearly higher than between population genetic diversity (D ST = 0.06) UPG-MA showed a high level of genetic variation between major and minor populations of V. faba L. Particularly the minor populations showed a high level of diversity and was divided into two subclusters. Ltaifia was separated from the other populations. In addition to a high grain yield, I.Z. Backouchi et al. 7588©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 14 (3): 7587-7596 (2015) these populations showed the lowest Nei and Shannon indices (H = 0.08 and I = 0.13) justifying their homogeneity. For these reasons, these cultivars can be considered a selected population. However, the Takelsa population showed the highest Nei and Shannon indices (H = 0.13 and I = 0.21), indicating that this population was the most heterogeneous, which is interesting for breeding programs.

Common vetch (Vicia sativa L.) is an important annual forage legume. It is used as a cover crop, green manure, pasture legume and for silage and hay production. Its seeds can be used as a source of highly digestible protein and minerals in animal diets. However, their utilization as a feedstuff for monogastric animals is hindered by the fact that the seeds contain cyanogenic antinutritional factors that reduce their palatability. An effective utilization of V. sativa seeds as a successful monogastric feed stuff requires selection for higher protein availability and minimization of the cyanogenic antinutritional factors content. In this study, we selected one natural accession named Mjez Ibeb, from a collection of 25 accessions and cultivars, based on its superior agronomic performance and its naturally occurring genetic variation for cyanogenic traits. We investigated the genetic variation that exists for the cyanogenesis trait in more detail and analysed the seeds of 133 lines derived from accession Mjez lbeb. Of these, 40 naturally polymorphic lines that showed deficiencies in cyanogenesis and cyano‐amino acid content, were subsequently selected for detailed chemical analysis. Cyanogenic glucosides and cyano‐amino acid concentrations varied widely in the 40 lines. Multivariate analysis was performed and three lines (L16, L21, L18) with low content of cyanogenic compounds were identified.

SUMMARYDrought and salinity are two major environmental factors limiting faba bean growth, leading to considerable reduction in their productivity. The WRKY gene family act as major transcription factors that might play an important role in abiotic stress tolerance. In the present study, two partial sequences sharing significant homology with known WRKY genes were isolated from faba bean by polymerase chain reaction (PCR) amplification using degenerate primers targeting the well-conserved WRKY domain. The isolated WRKY gene fragments were designated as VfWRKY1 and VfWRKY2 showing 62% similarity between them. Sequence and phylogenetic analyses revealed that VfWRKY1 and VfWRKY2 belong to WRKY group I and could be grouped with their orthologues from other plant species. The gene expression profile of VfWRKY1 and VfWRKY2 in faba bean showed that they are significantly accumulated in various plant organs. Further, quantitative real-time PCR analysis showed that both transcripts were responsive to drought and salt stress, and also they are genotype dependent, meaning that different faba bean cultivars respond in a different way to drought and salt challenge. The expression patterns obtained suggest the important roles of VfWRKY1 and VfWRKY2 in drought and salt stress response and tolerance. This knowledge might be helpful in the identification of drought-tolerant cultivars and provide potential candidate markers for faba bean breeding in order to develop osmotic-stress-tolerant cultivars.

Description of the subject. Drought is one of the major abiotic factors affecting growth and productivity of plants by imposing certain morphological, physiological and biochemical changes at different growth stages. Objectives. The objective of this work is to study key morphological, physiological and biochemical responses of faba bean (Vicia faba L. var. 'minor') to soil water deficit stress and to assess the contribution of genetic factors in improving faba bean tolerance to water deficit. Method. Plants of 11 faba bean cultivars were grown in the greenhouse and subjected to three levels of water deficit (90, 50 and 30% of field capacity [FC]) in a simple randomized design for 20 days. Water deficit effects on plant growth, relative water content (RWC), gas exchange, chlorophyll a (Chla) and chlorophyll b (Chlb) content, osmoprotectant accumulations (such as proline and soluble sugars), antioxidant enzyme activities and grain yield were determined. Results. Soil water deficit stress reduced growth and affected physiological parameters, especially antioxidant enzyme activities. Water deficit also increased proline, soluble sugars and protein contents. The studied cultivars significantly differed in their responses to water deficit stress. Photosynthetic parameters were less affected in the 'Hara' cultivar. Furthermore, this cultivar produced the highest value of grain yield at 30% FC, and showed higher antioxidant enzyme activities (CAT, GPX and APX), osmoprotectant accumulations, Chlb and RWC. The 'Hara' cultivar was found to be more tolerant to water deficit stress than the other cultivars. Conclusions. Our methodology can be used for assessing the response of faba bean genetic resources to soil water deficit. The identified tolerant cultivar can be utilized as a source for water stress tolerance in faba bean breeding programs aimed at improving drought tolerance.