Changes in Antioxidant Enzymes Activity and Oxidative Damage in Four Argania spinosa Ecotypes Under Water Stress Conditions

_Argania spinosa_ L. Skell, a tree endemic of Morocco, grows in semiarid and arid areas. Biochemical response to drought in four ecotypes of the _A. spinosa_ was compared. Choice of ecotypes was based on evident differences in geographical features in south-west Morocco: two coastal ecotypes (Essaouira and Agadir) and two paralittorale ecotypes (Aoulouz and Lakhssas). Lipid peroxidation (malonyldialdehyde (MDA)), content of endogenous hydrogen peroxide (H2O2) and antioxidant enzyme system (Catalase (CAT), Ascorbate peroxidase (APX), Total peroxidase (POD) and Polyphenoloxidase (PPO) were measured in control (100% relative humidity (RH) at field capacity (FC)) and water-stressed plants (50 and 25% RH at FC). For all ecotypes, drought stress significantly increased the contents of MDA and H2O2 and an ecotype effect was noted. According Two-way ANOVA analysis, the ecotype x watering regime interaction was highly significant. We found an increase in the activities of the four ROS-scavenging enzymes and an ecotype effect was noted. Ecotype x watering regime interaction shows that only the CAT and APX activities were significant. Highest values of POD and PPO activities were found in both paralittorale ecotypes. Increase in antioxidant enzyme activities appears to be an adaptive response to restore the reactive oxygen species in their homeostasis. The four study ecotypes were separated by two discriminant functions obtained by canonical discriminant analysis. Coastal ecotypes are separated from the paralittorale ecotypes mainly by POD and PPO activities and MDA content

Genetic structure and core collection of the World Olive Germplasm Bank of Marrakech: towards the optimised management and use of Mediterranean olive genetic resources

The conservation of cultivated plants in ex-situ collections is essential for the optimal management and use of their genetic resources. For the olive tree, two world germplasm banks (OWGB) are presently established, in Córdoba (Spain) and Marrakech (Morocco). This latter was recently founded and includes 561 accessions from 14 Mediterranean countries. Using 12 nuclear microsatellites (SSRs) and three chloroplast DNA markers, this collection was characterised to examine the structure of the genetic diversity and propose a set of olive accessions encompassing the whole Mediterranean allelic diversity range. We identified 505 SSR profiles based on a total of 210 alleles. Based on these markers, the genetic diversity was similar to that of cultivars and wild olives which were previously characterised in another study indicating that OWGB Marrakech is representative of Mediterranean olive germplasm. Using a model-based Bayesian clustering method and principal components analysis, this OWGB was structured into three main gene pools corresponding to eastern, central and western parts of the Mediterranean Basin. We proposed 10 cores of 67 accessions capturing all detected alleles and 10 cores of 58 accessions capturing the 186 alleles observed more than once. In each of the 10 cores, a set of 40 accessions was identical, whereas the remaining accessions were different, indicating the need to include complementary criteria such as phenotypic adaptive and agronomic traits. Our study generated a molecular database for the entire OWGB Marrakech that may be used to optimise a strategy for the management of olive genetic resources and their use for subsequent genetic and genomic olive breeding

Patterns of Genetic Diversity and Structure at Fine Scale of an Endangered Moroccan Endemic Tree (Argania spinosa L. Skeels) Based on ISSR Polymorphism

The preservation of the diversity of endangered populations of argan trees, in their natural habitat, is a crucial step toward their conservation. The aim of the present study was to evaluate the genetic diversity of the argan trees in the wild, and to establish a phylogenetic map using DNA fingerprints. The ultimate goal was to develop a core set that would represent the existing diversity in the whole germplasm. In regard to this, 200 samples of Argania spinosa individual trees were collected from 10 different provenances in the region of Essaouira (Morocco). The genetic variation between and within these argan trees was investigated using previously described Inter-Simple Sequence Repeat markers. These markers generated a total of 149 fragments, in which 148 (99.33%) were polymorphic. The samples collected in the 'Ouled Lhaj' provenance showed the lowest diversity (% of polymorphic locus P=48.32%; genetic diversity Nei h=0.153; allelic richness A=1.483), compared to those collected in the 'Mramer' provenance (%P=68.46%; h=0.233; A=1.685). Also, the results showed a high level of genetic differentiation among provenances (AMOVA=44%, Gst=0.40), and a limited gene flow (Nm=0.73) between the provenances. In addition, these data suggested a low correlation between the genetic diversity of the tree and their respective geographical location in relation to the proximity to the littoral. Finally, a core collection of 13 genotypes that represent the essential of the detected diversity was established. The distribution pattern of this genetic diversity provides an important baseline data for the conservation strategies of argan tree species in the wild

Diversity of arbuscular mycorrhizal fungi in the rhizosphere of saffron (Crocus sativus) plants along with age of plantation in Taliouine region in Morocco

Saffron cultivation is a viable alternative for marginal areas where low soil fertility and water availability severely limit the cultivation of other crops with higher water and input requirments. Under these conditions, arbuscular mycorrhizal fungi (AMF) are an essential alternative for maintaining fertility and water conservation, stimulating growth, and providing plant protection against soil-borne diseases. The aim of this work is to highlight the diversity of the arbuscular mycorrhizal fungi communities associated with saffron roots in plantations of different ages (two, four and ten years old) in the region of Taliouine (Morocco). The highest number of endomycorrhizal spores was recorded in the rhizosphere of saffron plants harvested at the level of plots that have carried saffron for two years (138.66/100 g soil), while the lowest number was observed in the rhizosphere of plants of plots that are occupied for 10 years by saffron. All collected spores from plots under study represent 17 morphotypes belonging to 5 genera: Glomus (7 species), Acaulospora (7 species), Rhizophagus (one species), Densicitata (one species), and Funneliformis (one species)

Electrolyte ions and glutathione enzymes as stress markers in Argania spinosa subjected to drought stress and recovery

Understanding the mechanisms underlying Argania spinosa responses to drought stress is essential for its regeneration and domestication. Toward that end, an integrative study of tolerance responses to drought stress in four A. spinosa ecotypes (2 contrasting coastal ecotypes (Adm and Rab) and 2 contrasting inland ecotypes (Alz and Lks)) have been conducted. Responses to soil drying and re -watering were measured at physiological and biochemical levels. Soil drying resulted in significant increase in leaf concentrations of potassium (K+), calcium (Ca2+) and magnesium (Mg2+) with differential responses between ecotypes. The glutathione-related enzymes: glutathione peroxidase (GP), glutathione reductase (GR) and glutathione S-transferase (GST) showed a significant increase in their enzymatic activity in A. spinosa plants subjected to drought stress. Additionally, a significant increase in thiol protein content in the four ecotypes was recorded, during drought stress. These antioxidant traits responded differently depending on ecotype. However, rapid and significant changes in the studied physiological and biochemical traits were observed during recovery from drought, only after four days. According to the traits having the most discriminating power, the both inland ecotypes, especially Lks ecotype, seem to be potential candidates for regeneration of argan forest and their domestication in arid and semi-arid environments.Key words: Argania spinosa, drought stress, glutathione enzymes, thiol compounds, recovery

Effect of phospho-compost and phosphate laundered sludge combined or not with endomycorrhizal inoculum on the growth and yield of tomato plants under greenhouse conditions

The study aims to evaluate the eff ect of endomycorrhizal inoculum (arbuscular mycorrhizal fungi), phospho-compost and phosphate sludge in single (M, PC, PS) or dual combinations (PC+M, PS+M, PS+PC) compared to agricultural and Mamora soils (A and S) on the growth, fl owering, and yield of tomato plants. Among the studied treatments, the substrates containing 5% of phospho-compost combined with endomycorrhizal inoculum (PC+M) gave the most positive eff ect followed by phospho-compost (PC) and endomycorrhizal inoculum (M). In response to PC+M substrate, tomato plant height, the number of leaves and fl owers attained 90 cm, 30, and 25, respectively. In substrates PC and M, tomato plants showed a height of 85 and 75 cm, leaves number of 30 and 19 leave/plant and number of fl owers of 21, and 19 fl ower/plant. An optimal yield with (12 fruits/plant) was recorded in tomato plants grown on the substrate amended with bio-inoculant (AMF) and phospho-compost at a rate of 5%. In terms of qualitative parameters, the highest fresh and dry weight of aerial plant parts and root system were recorded in tomato plants grown in culture substrate incorporating 10 g of endomycorrhizal inoculum and 5% of phospho-compost reaching respectively103.4 g, 34 g 90.1 g, 28.9 g as compared to 87, 51, 23 and 24.1 g noted by tomato plants on the substrate with phospho-compost (5%) (PC). The highest mycorrhization parameters (frequency (F), intensity of mycorrhization (M), average arbuscular content (A), average vesicular content (V), average intraradicular spore content (S)) were found in the roots of tomato plants growing on substrates amended with 5% phospho-compost plus 10 g of endomycorrhizal inoculum, with percentages of 100% F, 61% M, 40.67% A, 18.36% V, and 56.9% S

Antidiabetic potential of mucilage fraction extracted from Astragalus gyzensis seeds

The objective of the current work is to extract a new mucilage fraction from Astragalus gyzensis Bunge. seeds, which are collected from the El-Oued province (septentrional Algerian Sahara) and evaluated for their antidiabetic potential. The mucilage fraction is obtained using hot water extraction followed by alcoholic precipitation of polysaccharides by cold ethanol (96%). The primary investigation was performed by describing the main structural features of the extract through colorimetric assays, Fourier-transform infrared spectroscopy and thin-layer chromatography analysis using two systems. Biological activity was also monitored by antidiabetic activity by testing the inhibition of α-amylase and α-glucosidase enzymes in vitro. The extraction yield was 20.69%. The chemical composition mainly consisted of 78.60±0.29% carbohydrates, among them 63.92±0.67% neutral sugar, 15.78±0.76% uronic acid, 8.08±0.04% proteins and 2.57±0.05% phenolic compounds. The results obtained by thin-layer chromatography analysis showed the dominance of mannose and galactose. Fourier-transform infrared spectrum showed characteristic bands expected galactomannans. The investigations highlighted the antihyperglycemic effect in a dose-dependent manner by the inhibition of the α-amylase enzyme (IC50=0.8±0.005 mg/mL). These factors make it suitable for the industrial application of dietary supplement fiber made for diabetic individuals. DOI: http://dx.doi.org/10.5281/zenodo.761853

Saffron endomycorrhizae: diversity and effect on plant growth and corm formation

Saffron cultivation is an important alternative for marginalized areas. Due to low soil fertility and low water availability, arbuscular mycorrhizal fungi are an essential alternative for maintaining fertility and water economy, stimulating growth and protecting plants against soil diseases. Studies on the diversity of endomycorrhizal fungi in the rhizosphere of Crocus sativus in Taliouine (Tinfat), located in Morocco, revealed the impact of age saffron plantations. A greater endomycorrhizal fungi density was recorded in the rhizosphere of saffron plants from plots operated for 2 years (138.66/100 g of soil) over that occupied for 10 years. Seventeen morphotypes of collected spores belong to 5 genera: Glomus (seven species), Acaulospora (seven species), Rhizophagus, Densicitata, and Funneliformis (one species). The weak endomycorrhizal species richness can be explained by the accumulation of C. sativus residues over time and its allelopathic effect. The beneficial effect of composite endomycorrhizal inocula, originating from Moroccan saffron plantations, was obvious in the growth of saffron plants, mother bulb number, the leaves length, root, and vegetative masses. These inocula mycorrhized over time saffron plants’ roots and can sporulate at the level of the rhizosphere of these plants. The use of composite inocula, as biofertilizers, can be one of the solutions for sustainable agriculture

Diversity of Arbuscular Mycorrhizal Fungi in the Rhizosphere of <em>Argania spinosa</em> in Morocco

Despite the importance of arbuscular mycorrhizal fungi (AMF) within forest and agroecosystems, few data are available about how AMF communities are structured in the root zone of the argan tree. Some studies have characterized endomycorrhizal fungi population occurring in rhizosphere soils of argan trees grown in southwest of Morocco, numerous sites in this area harbored unexplored communities. The endomycorrhizae diversity of rhizosphere soils collected from 15 argan forest stands located in Lakhssas, Smimou, Ait Baha, Tamanar, Essaouira, Taroudant (Elkodya), Irherm, Guelmim, Imsouane, Anzi, Tiznit, Taghazoute, Ait Melloul, Bouizakarne, and Oulad Teima have revealed the presence of different AMF communities sharing some species but dissimilar AMF community compositions are noted according to sampling time and site. Additionally, the diverse AMF structures detected such as vesicles, arbuscules and hyphae reflect implicitly the germination of AMF propagules in the rhizospheric area of the Argan tree. The pre-evaluation of AMF in the soil through spores’ density can indicate AMF community dynamics, signaling either the adaptability of mycorrhizal symbionts to the local conditions or its decline. In total, 39 morphotypes of endomycorrhizal fungal spores were identified and described, representing seven genera: Glomus (15 species), Scutellospora (3 species), Entrophospora (4 species), Pacispora (2 species), Gigaspora (4 species), Acaulospora (10 species), and Ambispora (1 species). The genus Glomus has a wide occurrence and had the largest number of species. This chapter gives a great overview of the mycorrhizal status of argan trees in their natural habitats of the main Moroccan argan forests