Use of an adsorbent and antioxidants to reduce the effects of leached phenolics in in vitro plantlet regeneration of faba bean

Development of a reliable in vitro regeneration protocol is necessary to facilitate genetic transformation of faba bean. However, leaching of phenolics from the explants of most genotypes of faba bean to theculture medium causes browning, and eventually kills the explants, hindering in vitro regeneration. This study is aimed to minimize the effect of phenolics and to identify the most suitable types of explants forin vitro regeneration. We pre-treated faba bean seeds in polyvinylpyrrolidone (PVP), then cultured different types of explants on tissue culture media supplemented with an adsorbent (activated charcoal) and antioxidants (ascorbic acid, cysteine and silver nitrate). Our results showed that treating the over night soaked seed (after removing the seed coat) with PVP solution (1000 mg/l) for 1 h, followed by culturing in Murashige and Skoog medium (MS medium) with 3% (w/v) sucrose, 0.8% (w/v) agar, 2 mg/l 6-benzylaminopurine and 2 mg/l thidiazuron, supplemented with ascorbic acid (1 mg/l) or activatedcharcoal (10 g/l), greatly reduced lethal browning in explants and improved shoot regeneration. The shoots rooted on half-strength MS medium supplemented with 0.5 mg/l -naphthaleneacetic acid. Thecotyledonary node is the most suitable type of explant for regeneration. Regenerated plantlets were successfully established in pots and set seeds in the green house

Analysis of diversity genetic of Moroccan net blotch populations using amplified fragment length polymorphism (AFLP) markers

Net blotch caused by Pyrenophora teres f. teres is the most harmful foliar disease in barley generating significant economic losses in Morocco. Populations of P. teres f. teres were collected from different regions of Morocco. Thirty five (35) P. teres f. teres isolates, single conidial, were isolated and were subjected to molecular study using amplified fragment length polymorphism (AFLP) technique. Out of the fourteen primers combinations tested, four primers combinations were selected to disclose the polymorphism between the different P. teres f. teres isolates. The molecular characterization of these isolates showed high degree of polymorphism reaching 95% and identifying 25 specific genotypes. The genetic variability of the different isolates of P. teres f. teres within and between Moroccan regions was highlighted, disclosing no linkage between the isolates and their geographical origins. This result might be due to informal material flow between regions.Key words: Barley, net blotch, Pyrenophora teres f. teres, amplified fragment length polymorphism (AFLP), genetic diversity

Virulence of Moroccan f. Revealed by International Differential Barley Genotypes

Pyrenophora teres f. teres (Ptt), causing net blotch in barley, is an important and frequently isolated leaf pathogen across the globe. The virulence spectrum of Ptt from North Africa including Morocco is poorly understood. Sixteen barley genotypes were challenged, at seedling stage, with 15 Ptt isolates that were collected from different agroecological zones of Morocco. The experiment was conducted in a factorial arrangement of treatments in a randomized complete block design with three replicates. The ANOVA revealed highly significant (P < 0.001) effects of genotype (G), isolate (I) and G×I interaction explaining 23.2, 62.5, and 13.9% of the variation, respectively. Therefore, the current study revealed highly diverse virulence pattern of Moroccan isolates. Furthermore, the results indicated that minor virulence of Ptt isolates dominated over virulence interaction. In addition, Taffa (6-rowed) and Aglou (2 rowed), had the highest level of resistance to Ptt, while Coast and Rabat071 were the most susceptible genotypes. Pt2, Pt7, Pt8 and Pt4 were being the most virulent isolates, while Pt10 and Pt11 were the least virulent isolates. The emergence of the new Ptt pathotypes, which were highly virulent to durable resistance in Rabat071 posed a risk of breaking down the currently deployed resistance to net blotch in Morocco. A careful evaluation and selection of Ptt isolates based on minor virulence pattern to barley genotypes is essential for successful barley breeding program for resistance to net blotch in Morocco

Mutation discovery for crop improvement

Increasing crop yields to ensure food security is a major challenge. Mutagenesis is an important tool in crop improvement and is free of the regulatory restrictions imposed on genetically modified organisms. The forward genetic approach enables the identification of improved or novel phenotypes that can be exploited in conventional breeding programmes. Powerful reverse genetic strategies that allow the detection of induced point mutations in individuals of the mutagenized populations can address the major challenge of linking sequence information to the biological function of genes and can also identify novel variation for plant breeding. This review briefly discusses recent advances in the detection of mutants and the potential of mutagenesis for crop improvement

First draft genome assembly of the Argane tree (Argania spinosa)

Background: The Argane tree (Argania spinosa L. Skeels) is an endemic tree of southwestern Morocco that plays an important socioeconomic and ecologic role for a dense human population in an arid zone. Several studies confirmed the importance of this species as a food and feed source and as a resource for both pharmaceutical and cosmetic compounds. Unfortunately, the argane tree ecosystem is facing significant threats from environmental changes (global warming, over-population) and over-exploitation. Limited research has been conducted, however, on argane tree genetics and genomics, which hinders its conservation and genetic improvement. Methods: Here, we present a draft genome assembly of A. spinosa. A reliable reference genome of A. spinosa was created using a hybrid de novo assembly approach combining short and long sequencing reads. Results: In total, 144 Gb Illumina HiSeq reads and 7.2 Gb PacBio reads were produced and assembled. The final draft genome comprises 75 327 scaffolds totaling 671 Mb with an N50 of 49 916 kb. The draft assembly is close to the genome size estimated by k-mers distribution and covers 89% of complete and 4.3 % of partial Arabidopsis orthologous groups in BUSCO. Conclusion: The A. spinosa genome will be useful for assessing biodiversity leading to efficient conservation of this endangered endemic tree. Furthermore, the genome may enable genome-assisted cultivar breeding, and provide a better understanding of important metabolic pathways and their underlying genes for both cosmetic and pharmacological purposes