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The Quercus genus provides ecological importance by improving the ecosystem in urban and forest settings. However, the massive exploitation of Quercus species without regulation causes deforestation in many areas. Reforestation of the affected areas with Quercus plantations derived from in vitro propagation is the best option. The Quercus micropropagation permits the cultivation of different parts of the plant in various medium compositions. Buds, meristems, and shoot tips can produce genetically stable clones, but meristems and embryos could be used to avoid contamination. Otherwise, the highest multiplication rate of Quercus is obtained by somatic embryogenesis. During in vitro multiplication, several problems can occur, such as basal calluses, vitrification, tissue necrosis, and phenol accumulation. Alternatively, adding supplements to the basal medium, like polyvinylpyrrolidone or ascorbic acid as well as casein hydrolysate, improves the Quercus in vitro culture by control of phenolics and tissue necrosis, respectively. The increase in agar and calcium concentrations and the removal of chloride from the medium reduce vitrification. The Woody Plant Medium is optimal for Quercus in vitro multiplication. Furthermore, the success of acclimatization is guaranteed by the transplantation of plantlets in sterile soil and their preservation in a high level of relative humidity alongside regular irrigation to avoid dehydration of plants. This review detailed an overview of different steps required for Quercus micropropagation and the different ameliorative strategies implemented to overcome the problems encountered during Quercus in vitro multiplication. [ABSTRACT FROM AUTHOR]

Salinity is one of the most significant environmental factors limiting legumes development and productivity. Salt stress disturbs all developmental stages of legumes and affects their hormonal regulation, photosynthesis and biological nitrogen fixation, causing nutritional imbalance, plant growth inhibition and yield losses. At the molecular level, salt stress exposure involves large number of factors that are implicated in stress perception, transduction, and regulation of salt responsive genes' expression through the intervention of transcription factors. Along with the complex gene network, epigenetic regulation mediated by non-coding RNAs, and DNA methylation events are also involved in legumes' response to salinity. Different alleviation strategies can increase salt tolerance in legume plants. The most promising ones are Plant Growth Promoting Rhizobia, Arbuscular Mycorrhizal Fungi, seed and plant's priming. Genetic manipulation offers an effective approach for improving salt tolerance. In this review, we present a detailed overview of the adverse effect of salt stress on legumes and their molecular responses. We also provide an overview of various ameliorative strategies that have been implemented to mitigate/overcome the harmful effects of salt stress on legumes. [ABSTRACT FROM AUTHOR]

Aqueous seaweed extracts are a biological product which have beneficial effects on plant growth as well as improving their resistance to several biotic and abiotic stresses. This work aimed to evaluate the effect of aqueous extracts of three seaweeds Fucus spiralis, Cystoseira ericoides (Phaeophyceae) and Ulva lactuca (Chlorophyceae) harvested from Atlantic coast of Rabat region in Morocco, on lead (Pb) tolerance and accumulation in tomato (Solanum lycopersicum) plants. Aqueous extracts were obtained by the combination of 2 extraction processes, ultrasonication and heating. The brown seaweeds F. spiralis and C. ericoides extracts had good antioxidant activity in the DPPH assay. The growth and physiological parameters were compared between Solanum lycopersicum seedlings grown in hydroponic conditions at 0 and 100 μmol Pb with or without 4% seaweed extract. The F. spiralis and C. ericoides extracts significantly increased the aboveground parts and roots biomass compared to control plants treated with Pb alone. In Pb stress conditions, these seaweed extracts enhanced the plant's tolerance with a reduction of anthocyanin and proline content. F. spiralis extract treatment led to a significant Pb accumulation in aboveground parts of the plant. The effect of U. lactuca extract on tomato plants biomass, anthocyanin and proline was not significant. The study demonstrated that the aqueous extracts of F. spiralis and C. ericoides improved the plant response to heavy metals stress, highlighting the potential use of these seaweeds in phytoremediation processes. [ABSTRACT FROM AUTHOR]

The cultivated barley ranks fourth cereal crop in the world. The demand for higher-yielding, nutritious, and better-adapted crop varieties has increased the need to exploit genebanks diversity. Thus, assessing the genetic diversity of barley is essential to determine the genetic relationship between lines and deploy novel alleles in breeding programs. Here, we used 14 polymorphic Simple Sequence Repeat (SSR) markers to assess genetic diversity, genetic relationship, and population structure of 113 barley lines originated from 14 countries, and the majority from Africa. The average alleles per locus of 5.36, Polymorphism Information Content (PIC) of 0.57, and genetic diversity of 0.61 indicate a high degree of genetic variation in this collection. The Analysis of Molecular Variance AMOVA showed genetic variation within countries to be higher (74%) than among countries (26%). The STRUCTURE analysis was consistent with neighbor-joining clustering and principal components analysis, which identified three main subpopulations clustered primarily according to their geographic origin. Growing environments, migration between and within countries might have caused a considerable genetic diversity observed in the North African barley germplasm. The results of this study contribute to the conservation and utilization of these barley germplasm. [ABSTRACT FROM AUTHOR]

Glutenin is a major protein fraction contributing to the functional properties of gluten and dough. The glutenin constitutes 30-40% of the protein in wheat flour and about half of that in gluten. It is essential to identify correct glutenin alleles and to improve wheat quality by selecting alleles that exert favorable effects. Moroccan wheat cultivars are unique in West Asia and North Africa region, since many of them possess resistance to Hessian fly, a pest, which is becoming important in other countries in the region. Hence, these cultivars are being used as donor for the resistance in the breeding program. Here, we determine the allelic variation in high-molecular weight glutenin subunits (HMW-GS) and low-molecular weight glutenin subunits (LMW-GS) in Moroccan cultivars of bread and durum wheat using the gene-specific PCR markers. In 20 cultivars of bread wheat, 9 different allele variants were detected at HMW-GS and 13 different allele variants were detected at LMW-GS, in which the alleles Glu- A1b (2*), Glu- B1i (17 + 18), Glu- B1c (7*/7 + 9), Glu- D1d (5 + 10) , Glu- A3c, Glu- B3 h, and Glu- D3b were the most frequents. In 26 cultivars of durum wheat, less allelic variation was found: seven different allele variants at HMW-GS and six different allele variants at LMW-GS were identified, in which the major alleles were Glu- A1c (null), Glu- B1b (7 + 8), Glu- B1e (20), Glu- A3c, and Glu- B3d. The mean value of the genetic diversity for the glutenin loci was 0.502 in bread wheat and 0.449 in durum wheat. Most of the glutenin alleles carried by Moroccan bread wheat cultivars impart good bread-making quality. Most of the durum wheat glutenin alleles were related to low strength dough or poor quality and need to be improved. To improve quality of Moroccan durum wheat, essentially, Glu- A1c and Glu- B3d alleles of the genes should be replaced with the better alleles through breeding. [ABSTRACT FROM AUTHOR]

Genetic characterization, diversity analysis and estimate of the genetic relationship among varieties using functional and random DNA markers linked to agronomic traits can provide relevant guidelines in selecting parents and designing new breeding strategies for marker-assisted wheat cultivar improvement. Here, we characterize 20 Moroccan and 19 exotic bread wheat (Triticum aestivum L.) cultivars using 47 functional and 7 linked random DNA markers associated with 21 loci of the most important traits for wheat breeding. The functional marker analysis revealed that 35, 45, and 10% of the Moroccan cultivars, respectively have the rust resistance genes (Lr34/Yr18/ Pm38), dwarfing genes (Rht1b or Rht2b alleles) and the leaf rust resistance gene (Lr68). The marker alleles for genes Lr37/Yr17/Sr38, Sr24 and Yr36 were present only in the exotic cultivars and absent in Moroccan cultivars. 25% of cultivars had 1BL.1RS translocation. 70% of the wheat cultivars had Ppo-D1a and Ppo-A1b associated with low polyphenol oxidase activity. 10% of cultivars showed presence of a random DNA marker allele (175 bp) linked to Hessian fly resistance gene H22. The majority of the Moroccan cultivars were carrying alleles that impart good bread making quality. Neighbor joining (NJ) and principal coordinate analysis based on the marker data revealed a clear differentiation between elite Moroccan and exotic wheat cultivars. The results of this study are useful for selecting suitable parents for making targeted crosses in marker-assisted wheat breeding and enhancing genetic diversity in the wheat cultivars. [ABSTRACT FROM AUTHOR]

Wheat and barley are the most important cereal crops in Morocco and in North Africa. Their production is constrained by several biotic and abiotic stresses. Climate change has further aggravated these problems. Since the landraces, old and newer varieties are reservoirs of variability and adaptive traits required for breeding for resistances to stresses and adaptation of climate change, we screened 400 bread wheat and 295 durum wheat accessions at Sidi El Aidi (Morocco) during 2015--16 and identified 4 lines (Kharouba, 2837, CWI77963 and CWI9941) highly resistant and 290 resistant/moderately resistant to yellow rust respectively. Similarly, Screening of 452 accessions of barley in the same location resulted in the identification of 116 moderately resistant accessions to net blotch disease. Some of the identified resistance sources are being used to make genetic crosses for studying genetics of resistance, developing improved cultivars and to increase cultivar diversity in the country which can enhance 'life of the resistant cultivars' and adaptation to climate change. As a first step and baseline information, we evaluated phenotypic and genotypic diversity of a set of 20 improved bread wheat cultivars released in Morocco since 1980s. The results revealed that many of the wheat cultivars were susceptible to prevailing biotypes of the Hessian fly and yellow rust. The genotyping of the 20 Moroccan wheat cultivars using 14 microsatellite markers revealed 59 alleles (Mean = 4.21), substantial genetic diversity (Range = 0 to 0.895, Mean = 0.576) and genetic distance (0.143 to 1.00). However, total number of alleles decreased (8.3%) in the cultivars developed during recent period (1990s) compared to that of 1980s. In order to enhance biotic and abiotic stress tolerance, end-use quality and allelic diversity of wheat cultivars in Morocco, 8 exotic wheat cultivars having various useful known genes were deployed and being used to make crosses with Moroccan cultivars. Further, these Moroccan cultivars and the exotic cultivars were characterized using 47 gene specific or functional markers and 7 linked random DNA markers associated with 21 loci of the most important traits for wheat breeding. The functional marker analysis revealed that 35 and 45% of the Moroccan cultivars, respectively have the rust resistance genes (Lr34/Yr18/ Pm38) and dwaring genes (Rht1b or Rht2b allele). The desired marker alleles for genes Lr37/Yr17/Sr38, Sr24 and Yr36 were present only in the exotic cultivars and absent in Moroccan cultivars. 25% of cultivars had 1BL.1RS translocation. 70% of the wheat cultivars had Ppo-D1a and Ppo-A1b associated with low polyphenol oxidase activity. 10% of cultivars showed presence of a random DNA marker allele (175 bp) linked to Hessian fly resistance gene H22. Integration of molecular markers within traditional breeding systems had enabled to select superior genotypes for traits that are difficult to select based solely on phenotype or to pyramid desirable combinations of genes into a single genetic background. The targeted crosses were made and subsequent generations were carried forward through traditional breeding systems and also in some cases through doubled haploids (DH) to speed up development of homozygous plants. Though marker-assisted breeding (MAB) can be applied to all segregating generations, we most commonly applied to early generations, including haploids, F2, BC1F1, BC1F2 and the F1 of complex crosses to enrich populations with favourable genes and their combinations. MAB also offered the opportunity to hasten transfer of desirable alleles from un-adapted exotic genetic backgrounds into a desirable germplasm through crossbreeding. Marker-linked loci responsible for traits such as resistance to diseases, quality and phenology were selected in the segregating populations and the desired genotypes were carried forward until they reach nearly homozygous. Once, the selected genotypes reach F6 or later generations, they were validated for the selected traits under field conditions. Only lines expressing desired phenotypes were selected for seed increase and subsequent preliminary yield trials and multilocation trials. In conclusion, application of MAB and DH technologies greatly enhanced efficiency and effectiveness of utilization of the germplasm and enhanced genetic gains in the breeding programs. [ABSTRACT FROM AUTHOR]