Micropropagation of Carob tree (Ceratonia siliqua L.) by cotyledonary buds

La micropropagation du Caroubier (Ceratonia siliqua L.) par culture de bourgeons cotylédonaires de plantules âgées de 13 jours a été étudiée sur le milieu WPM additionné de microéléments et de vitamines MS. La comparaison de l’effet de quatre cytokinines (BAP, zéatine, kinétine et 2-iP) a montré que la croissance des pousses est surtout stimulée par la zéatine (1 mg/l) ; alors que l’organogenèse se fait mieux en présence de la BAP ou de la zéatine (1 mg/l). L’effet de quatre auxines (AIA, AIB, ANA et 2,4-D) à faible concentration (0,1 mg/l) combinées à la BAP (0,5 mg/l) a été aussi testé, et a montré que l’ANA favorise la croissance des plantules et la néoformation de tiges. Toutefois, l’association de l’AG3 à différentes concentrations avec la BAP (0,5 mg/l) n’a pas eu d’effet significatif sur la culture de ces explants. La multiplication des pousses a été favorisée par des concentrations moyennes de BAP (0,5 à 1 mg/l) seule ou associée avec l’AG3 (0,2 mg/l). Parmi les auxines testées au cours de la phase d’enracinement, l’AIB (2 mg/l) s’est avéré la plus efficace pour la rhizogenèse.In vitro micropropagation of Carob tree (Ceratonia siliqua L.) by cotyledonary buds taken from 13 day old seedlings was attempted on Woody Plant Medium (WPM) supplemented with microelements and Murashige and Skoog (MS) vitamins. Comparison of the effect of four cytokinines (benzylaminopurine, zeatin, kinetinand 2-iP) has shown that seedling growth was stimulated by zeatin at 1 mg/L, while organogenesis was better under BAP or zeatin at 1 mg/L. The effect of four auxins (AIA, AIB, ANA and 2,4-D) at low concentrations (0.1 mg/L) combined with BAP at 0.5 mg/L has shown that Naphthalene Acetic Acid (NAA) stimulates better stem formation and growth. Moreover, combination of Gibberellic Acid (GA3) at different concentrations with BAP at 0.5 mg/L did not show a significant effect on growth. Shoot multiplication was stimulated by medium concentrations of BAP (0.5 - 1 mg/L) alone or with GA3 at 0.2 mg/L. Among the auxins tested during rooting, Indol-3-Butyric Acid (IBA) (2 mg/L) was found to be the most efficient for root formation

Assessment of the effect of environmental factors on the antagonism of bacillus amyloliquefaciens and trichoderma harzianum to colletotrichum acutatum

The effect of temperature (18˚C - 30˚C), water activity (0.85 - 1) and pH (4 - 9) was studied by dual culture technique on the antagonism of Bacillus amyloliquefaciens and Trichoderma harzianum to Colletotrichum acutatum, responsible of strawberry (Fragaria x ananassa (Weston) Duchesne ex Rozier) anthracnose. The antagonistic bacteria’s strains behave significantly and differently according to the parameters studied. These results reveal useful information about the applicability of their biocontrol in agricultural culture with the change of environmental factors

Effect of Amino Acids on Secondary Somatic Embryogenesis of Moroccan Cork Oak (Quercus suber L.) Tree

International audienc

Biosorption of Hexavalent Chromium Cr(VI) onto Ziziphus Lotus Fruits Powder: Kinetics, Equilibrium, and Thermodynamics

Ziziphus lotus has been the subject of several researchs because of its nutritional benefits and ecological attributes. The removal of hexavalent chromium Cr(VI) from a solution using powdered Zizphus lotus fruits, for its qualities of being inexpensive as well as environmentally friendly, was investigated. The results obtained showed that at pH=2, at 30°C, after 600 min of adsorbent/adsorbate contact, with 100 mg/L as initial concentration of Cr(VI) and a biosorbent dosage of 5 g/ L, the biosorption of Cr (VI) on Zizphus lotus fruit powder (ZLFP) is at its maximum rate. The sorption process was exothermic (∆H° = - 6.69 kJ/mol), and was characterized by a positive entropy values (∆S° = 46.76 J/K mol) suggesting a high affinity of the ZLFP for Cr (VI). Given that the Gibbs free energy (∆G°) is negative and decreases as temperatures increase from 293 to 323 K, the process of biosorption is both feasible and spontaneous. The Temkin model and the Langmuir model both generated excellent fits to the equilibrium data. The maximum monolayer biosorption capacity was 36.11 mg/g. The pseudo second order model was used to fit the kinetic data relating to the adsorption of Cr (VI) on the FP. The FTIR spectral analysis allowed the characterization of the biochemical groups mainly involved in the sorption of Cr (VI) ions on the ZLFP, and which are : N–C, H-O, O–C, H-C, and O=C. The capacity of Ziziphus lotus fruit (ZLFP) as an inexpensive, effective, and ecofriendly biosorbent is confirmed through this study

Micropropagation of Carob (Ceratonia silique L.) through Adventitious Buds of Immature Embryonic Cotyledons

Adventitious budding from embryonic cotyledons of immature seeds of carob was obtained. The combination of BAP (4.44 μM) and NAA (1.5 μM) furthered the neoformation of adventitious buds. These latter were multiplied on MS medium added with BAP (2.22 μM). Stems and leaves growing were improved by adding 2.02 μM GA3. Elongation was favored by 0.5 μM NAA. 70% of rooting was obtained with 10 μM IBA

Biology and Physiology of <I>Colletotrichum acutatum</I> Strains Causing Strawberry’s Anthracnose

International audienceSeven Colletotrichum acutatum strains isolated from strawberries were cultivated on various culture media and tested in vitro and in vivo on Fragaria x ananassa for anthracnose symptoms. PDA caused an optimum growth of all isolates, MEA, ML and Strawberry allowed a good but not optimal growth. Czapeck, Sabouraud and the organic medium from potato gave the lowest growth rate of all isolates. PDA allowed a good sporulation of isolates follow-up by strawberry, MEA; in contrast, ML, Czapeck and Sabouraud gave a low sporulation. The fungal development is maximal at 25˚C and 27˚C for all the isolates studied. No growth was observed at 5˚C and 37˚C. The studied strains developed at all pH values. They didn't develop at 0.6, 0.65 and 0.7 aw but mycelial growth was perfect at 1 and 0.95 aw. The in vitro test of the pathogenicity caused by C. acutatum strains on strawberry's leaves showed an increasing percentage of infection with time and different infection rates among C. acutatum strains, strain Ca6 having a pathogenic power very high compared to the other isolates. After in vivo inoculation and incubation of the seedlings, all isolates caused severe symptoms related to anthracnose on leaflets and petioles of the studied strawberry plants

In Vitro Evaluation of the Resistance of Seven Isolates of Colletotrichum acutatum to Thiram and Copper

International audienceSeven Isolates of Colletotrichum acutatum have been collected from strawberries attacked with anthracnose in the Loukous territory, Morocco. The study of the effect in vitro of 3 fungicides with Thiram as active substance and another one with copper on seven isolates of C. acutatum was studied. Thiram has a potent effectiveness on germination and is moderately effective on mycelial growth and sporulation. Copper has shown effectiveness on germination as variable activity in other strain's life stage

Determination of the Phenolic Profile by Liquid Chromatography, Evaluation of Antioxidant Activity and Toxicity of Moroccan Erica multiflora, Erica scoparia, and Calluna vulgaris (Ericaceae)

This study aimed to investigate the phenolic profile and selected biological activities of the leaf and aerial extracts of three Ericaceae species, namely Erica multiflora, Erica scoparia, and Calluna vulgaris, collected from three different places in the north of Morocco. The phenolic composition of all extracts was determined by LC coupled with photodiode array and mass spectrometry detection. Among the investigated extracts, that of E. scoparia aerial parts was the richest one, with a total amount of polyphenols of 9528.93 mg/kg. Up to 59 phenolic compounds were detected: 52 were positively identified and 49 quantified&mdash;11 in C. vulgaris, 14 in E. multiflora, and 24 in E. scoparia. In terms of chemical classes, nine were phenolic acids and 43 were flavonoids, and among them, the majority belonged to the class of flavonols. The antioxidant activity of all extracts was investigated by three different in vitro methods, namely DPPH, reducing power, and Fe2+ chelating assays; E. scoparia aerial part extract was the most active, with an IC50 of 0.142 &plusmn; 0.014 mg/mL (DPPH test) and 1.898 &plusmn; 0.056 ASE/mL (reducing power assay). Further, all extracts were non-toxic against Artemia salina, thus indicating their potential safety. The findings attained in this work for such Moroccan Ericaceae species, never investigated so far, bring novelty to the field and show them to be valuable sources of phenolic compounds with interesting primary antioxidant properties

Occurrence of three dominant epibenthic dinoflagellates (Ostreopsis spp., Coolia monotis and Prorocentrum lima) in relation to biotic substrates and environmental factors in a highly dynamic ecosystem, the Strait of Gibraltar (Southwestern Mediterranean)

No studies have been carried out on the benthic harmful algal blooms (BHABs) along the Strait of Gibraltar in the Mediterranean, and little is known about the diversity of blooming species. Here, epibenthic dinoflagellates were monitored at least biweekly over 18 months (May 2019–November 2020) in Oued Lihoud, Cap Malabata and Dalia on the thalli of five dominant macrophytes and in the water column. This is the first report on the seasonal distribution of BHAB species hosted by natural biotic substrates in the Strait of Gibraltar, which is known for high hydrodynamics, major entry of Atlantic waters and important maritime traffic. Three BHAB dinoflagellates were observed in the surveyed areas: Ostreopsis spp., Coolia monotis and Prorocentrum lima. The analysis of all data at the three sites showed that Dictyota dichotoma was the most favourable macroalgae host for these benthic dinoflagellates. The highest cell densities were observed in Cap Malabata for Ostreopsis spp. (2.7 × 105 cells/g fresh weight in September 2020), P. lima (4.57 × 104 cells/g FW in September 2020) and C. monotis (4.07 × 104 cells/g FW in June 2019). Phosphate and temperature were positively correlated to the abundances of the studied thermophilic BHAB species. In contrast, negative correlations were recorded with salinity, ammonium, nitrite, nitrate, DIN, nitrogen/phosphate ratio and suspended material, attesting of the complex relationships between environmental factors and BHAB species dynamic in each marine ecosystem. Toxin analyses of the natural phytoplankton assemblage during BHABs showed the presence of only lipophilic toxins, namely okadaic acid and dinophysistoxins produced by P. lima. These BHABs species have to be isolated to establish monoclonal cultures for ribotyping and ecophysiological investigations

Development of harmful algal blooms species responsible for lipophilic and amnesic shellfish poisoning intoxications in southwestern Mediterranean coastal waters

Mediterranean waters have undergone environmental changes during the last decades leading to various modifications of the structure of phytoplankton populations, especially Harmful Algal Blooms (HABs) species. Monitoring of the potentially toxic phytoplankton species was carried out biweekly in the western Mediterranean coast of Morocco from March 2018 to March 2019. Lipophilic Shellfish Toxins (LSTs) using LC-MS/MS and Domoic Acid (DA) using HPLC-UV were measured in the exploited mollusks, the cockle Acanthocardia tuberculata and the smooth clam Callista chione. We also determined the prevailing environmental factors in four surveyed sites (M'diq bay, Martil, Kaa Asras, and Djawn) selected to cover a variety of coastal ecosystems. Results showed that Pseudo-nitzschia spp. A DA producer species, was abundant with a pick of 50 × 103 cells l−1 on October 2018 in Djawn. Dinophysis caudata was the dominate Dinophysis species and showed a maximum density of 2200 cells l−1 on July in Djawn. Prorocentrum lima, an epibenthic dinoflagellate, appeared rarely in the water column with densities <80 cells l−1. Gonyaulax spinifera and Protoceratium reticulatum were found occasionally with a maximum density of 160 cells l−1. Karenia selliformis was detected only five times (<80 cells l−1) throughout the survey period. LC-MS/MS analyses revealed the presence of OA/DTX3, PTX-2, PTX-2 sa, and PTX-2 sa epi in the cockle at concentrations of up to 44.81 (OA/DTX-3+PTXs) ng g−1 meat. GYM-A was detected in the clam at concentrations of up to 4.22 ng g−1 meat. For the first time, AZAs and YTXs were detected in the southwestern Mediterranean with maximum values of 2.49 and 10.93 ng g−1 meat of cockle, respectively. DA was detected in moderate concentrations not exceeding 5.65 μg g−1 in both mollusks. Results showed that the observed toxic algae in the water column were responsible from the analysed toxins in the mollusks. It is likely that the southwestern Mediterranean waters could see the development of emergent species producing potent toxins (YTXs, AZAs, GYM-A). These dinoflagellates have to be isolated, ribotyped, and their toxin profiles determined