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A survey of entomopathogenic nematodes (EPN) was conducted in Morocco during 2015 and 2016 in three regions with varying topography, climate and vegetation (Meknes-El Hajeb, Ifrane and Tafilalet). ...

The main objective of this study was to evaluate the ability of both antagonistic bacteria Bacillus amyloliquefaciens (SF14) and Alcaligenes faecalis (ACBC1) used in combination with salicylic acid (SA) to effectively control brown rot disease caused by Monilinia fructigena. Four concentrations of salicylic acid (0.5%, 2%, 3.5%, and 5%) were tested under in vitro and in vivo conditions. Furthermore, the impact of biological treatments on nectarine fruit parameters&rsquo, quality, in particular, weight loss, titratable acidity, and soluble solids content, was evaluated. Regardless of the bacterium, the results indicated that all combined treatments displayed a strong inhibitory effect on the mycelial growth of M. fructigena and disease severity. Interestingly, all SA concentrations significantly improved the biocontrol activity of each antagonist. The mycelial growth inhibition rate ranged from 9.79% to 88.02% with the highest reduction rate recorded for bacterial antagonists in combination with SA at both concentrations of 0.5% and 3.5%. The in vivo results confirmed the in vitro results with a disease severity varying from 0.00% to 51.91%. A significant biocontrol improvement was obtained with both antagonistic bacteria when used in combination with SA at concentrations of 0.5% and 2%. The lowest disease severity observed with ACBC1 compared with SF14 is likely due to a rapid adaptation and increase of antagonistic bacteria population in wounded sites. The impact of all biological treatments revealed moderate significant changes in the fruit quality parameters with weight loss for several treatments. These results suggest that the improved disease control of both antagonistic bacteria was more likely directly linked to both the inhibitory effects of SA on pathogen growth and induced fruit resistance.

Fifty-five soil samples were collected from sugarbeet fields with rhizomania occurrence in the region of Tadla. BNYVV was ascertained by RT-PCR in 40 out of 55 fields surveyed and the positive samples were subsequently examined for the presence of the different pathotype of BNYVV. Using the same technique, a survey was simultaneously undertaken to identify the occurrence of other soil-borne viruses, which might frequently associate with BNYVV such as beet soilborne virus (BSBV), beet soilborne mosaic virus (BSBMV) and beet virus Q (BVQ). Results indicated that most samples were infected with A-type BNYVV, but only 9% of the samples were positive for B-type BNYVV. BNYVV (72.7%) was the most frequently detected, followed respectively by BSBV (36.36%) and BVQ (30.9%). However, P-type BNYVV was not detected at all. Our results also indicated the likely absence of BSBMV in the Tadla region. Surprisingly, among the 40 BNYVV-infected samples, 17 were also infected with BVQ and 20 with BSBV. In conclusion, BSBV occurred in triple infections with BNYVV and BVQ. In addition, there was only one sample revealed positive for both viruses BNYVV-B and BVQ and four samples for BSBV infection. Therefore, this study is the first investigation of BSBV and BVQ in fields-grown sugarbeet of Morocco.

To develop eco-friendly alternative control strategies for medfly, mass trapping trials were conducted in the central Morocco during the crop season 2016. Two control methods, mass trapping and the attract-and-kill technique were compared for the control of medfly on two peach varieties (?Rome Star? and ?Ryan Sun?) in Sefou district. For mass trapping, 62 traps/1.23 ha of MagnetTMMed type baited with ammonium acetate, trimethylamine, putrescine and 0.01 g of deltamethrin were installed on both varieties. In plots testing the attract-and-kill technique, treatments with malathion in mixture with protein hydrolyzate were applied to straw tufts attached to branches of the same varieties whenever 1 fly was caught on a Trimedlure trap installed at the center of each plot. The results showed that the number of flies captured by mass trapping reached 508 and 489 adults on ?Rome Star? and ?Ryan Sun?, respectively. The average number varied from 1 to 3 adults/trap/day, depending on the date of capture and the variety, and females accounted for 62-100% of total caught flies. In plots protected by the attract-and-kill technique, and taking into account the threshold adopted by the farm, 11 and 15 treatments were carried out respectively on the ?Ryan Sun? and ?Rome Star? varieties. Overall, infestation rates in plots did not exceed 0.3% before or at harvest with mass trapping versus 0.9% with the attract-and-kill technique. On fruit dropped on the ground, the infestation rate did not exceed 4% in mass trapping, compared to 11.5% in the chemically treated plots. Mass trapping was therefore proved to be an effective and eco-friendly tool for managing medfly on peach fruit.

Molecular characterization of Moroccan local fig (Ficus carica L.) germplasm was performed on the cultivars present in a collection of the National School of Agriculture of Meknes. A total of 22 fig samples were analysed using 7 ISSR primers and 9 loci S.S.R. A total of 54 I.S.S.R. polymorphic bands with an average of 8 per primers and 42 S.S.R. alleles with means 5 alleles per locus were revealed by these analyses. The ISSR markers allowed distinguishing 22 molecular profiles and S.S.R. loci differentiated between 21 different profiles. Pairwise Comparing, 87% of cultivars pairs were differentiated by 7 to 24 alleles and 89% by 9 to 29 ISSR bands. The statistical analysis and genetic distances have shown a wide molecular diversity in the collection, where the average observed heterozygosity was 0.42. The average similarity between cultivars is 70% using SSR markers and 71.6 for ISSR markers. The same SSR profile was obtained for Nabout1 and Nabout2 with 0 allele difference. Small differences of 1 to 6 alleles were obtained among cultivars which have the same names, which presumably corresponds to somaclonal variations obtained through intense vegetative propagation over long periods, while the differences over 7 alleles suggests the problems of homonyms.

Morocco is country concerned by climate warming, phenomenon affecting fruit tree phenology and yield. The present study aims at evaluating blooming and maturity date, fruit weight and yield of two peach varieties grown under Sais Valley conditions during three consecutive years (2017 to 2019). The results showed that, for both varieties, the flowering time was 7 days earlier in 2017 than in 2018. Temperatures were highest in 2017 than in other years of study. For both varieties, the maturity date was earliest in 2017 and 2019, compared to that recorded in 2018. During fruit growth period, the temperatures were higher in 2017 and 2019 compared to those recorded in 2018. The fruit weight was significantly low during the warmest years. From year to year, the fluctuation of flowering and maturity date of the peach in Sais Valley might be related to the variability of temperatures. The warmest years were characterized by early flowering and fruit maturity and low fruit weight.

The Mediterranean fruit fly, Ceratitis capitata Wiedemann, is a deleterious pest worldwide affecting fruit production. The entomopathogenic nematodes (EPNs) are a potential biocontrol agent that could be effectively used to control this Mediterranean fruit fly. In this study, five EPN strains reported from different fields in Morocco were evaluated for their efficacy against C. capitata. In laboratory assays, Steinernema feltiae-SF-MOR9, S. feltiae-SF-MOR10 and Heterorhabditis bacteriophora-HB-MOR7 strains showed significantly higher infectivity and penetration rates when compared to the other strains. S. feltiae-SF-MOR9 caused the highest larval mortality rate (80%) at 50 infective juveniles (IJs) cm−2. However, additional results showed that both S. feltiae strains were significantly effective in controlling C. capitata larvae in apricot (Prunus armeniaca) fruits on soil surface with high mortality rate at 50 and 100 IJs cm−2. Different soil textures and moisture levels resulted in a significant variation in EPN strain virulence against C. capitata. Sandy clay loam soil in combination with 50 IJs cm−2 of S. feltiae (SF-MOR9 or SF-MOR10) caused a higher mortality rate of C. capitata larvae. Furthermore, applying these EPN strains at 50–100 IJs cm−2 in combination with 10–15% moisture level showed optimal results against C. capitata larvae. Therefore, those two Moroccan EPN strains could be used as promising eco-friendly biological agents against C. capitata.

This study aimed at evaluating the antagonistic activity of 16 bacterial strains for the control of brown rot disease caused by Monilinia fructigena, and M. laxa under in vitro and a semi-commercial large-scale trial. These bacterial antagonists’ belonging to the genera Alcaligenes, Bacillus, Brevibacterium, Pantoea, Pseudomonas, and Serratia were previously proven effective for control of fire blight of apple. The in vitro dual culture bioassay showed the highest inhibition rates of mycelial growth ranging from 55 to 95% and from 43 to 94% for M. fructigena and M. laxa, respectively. The in vivo bioassay showed moderate and strong inhibition for M. fructigena and M. laxa, respectively. The inhibition rates were dependent on incubation time as well as pathogen virulence. The free-cell bacterial filtrate revealed substantial mycelial growth inhibition ranging from 66 to 86%. The inhibition of conidial germination was from 32 to 78%, suggesting the involvement of metabolites in their biocontrol activity. The antifungal effect of the volatile compounds (VCOs) was observed for all bacteria with mycelial inhibition varying from 12 to 70%. Overall, their efficacy was substantially affected by the nature of the bacterial strains and the modes of action. Taken together, these results underscore that ACBC1 and SF14 for M. fructigena and SP10 and ACBP1 for M. laxa were the most effective bacterial strains. These strains were confirmed effective in a semi-commercial large-scale trial. Interestingly, their efficacies were found to be comparable to those of both commercial BCAs (B. subtilis Y1336 and P. agglomerans P10c), but slightly lower than thiophanate-methyl fungicide. The ability of most bacterial strains to produce lytic enzymes (Amylase, Protease or Cellulase) and lipopeptides (bacillomycin, fengycin, iturin and surfactin) was demonstrated by biochemical and molecular analyzes. Therefore, our findings suggest that the bacterial antagonists ACBC1, SF14, SP10 and ACBP1, have the potential to prevent brown rot disease.

Rhizomania is one of serious threat to sugar beet production in Morocco and in several parts of the world. This disease led to a statistically significant decrease in the quality and yield of sugar beet plantations. Therefore, this study aimed at comparing the efficacy of six commonly used RNA extraction methods for the detection, recovery of RNA of beet necrotic yellow vein virus (BNYVV) and removal of amplification inhibitors by reverse transcription-polymerase chain reaction (RT-PCR). The efficiency of these extraction methods was then compared to that of a commercial isolation kit with high content of phenolic compounds. The results showed that the extraction with the lithium chloride technique, the commercial kit, and direct and membrane spotting crude extract methods were found effective in yielding a higher purity and a higher concentration of RNA when compared to the other tested methods. Extraction with the lithium chloride technique and the Qiagen kit (RNeasy Plant Mini Kit) allowed the most intense band, whereas the CTAB method has generated the least intense band. Furthermore, the silica capture extraction method did not yield any RNA after extraction and electrophoresis. Consequently, it was concluded that, of these six methods, the lithium chloride technique and the Qiagen kit are the most appropriate for the extraction of viral RNA from sugar beet samples prior to RT-PCR for detecting BNYVV.

International audience; TYLCV-IS76 is an unusual recombinant between the highly recombinogenic tomato yellow leaf curl virus (TYLCV) and tomato yellow leaf curl Sardinia virus (TYLCSV), two Mediterranean begomoviruses (Geminiviridae). In contrast with the previously reported TYLCV/TYLCSV recombinants, it has a TYLCSV derived fragment of only 76 nucleotides, and has replaced its parental viruses in natural conditions (Morocco, Souss region). The viral population shift coincided with the deployment of the popular Ty-1 resistant tomato cultivars, and according to experimental studies, has been driven by a strong positive selection in such resistant plants. However, although Ty-1 cultivars were extensively used in Mediterranean countries, TYLCV-IS76 was not reported outside Morocco. This, in combination with its unusual recombination pattern suggests that it was generated through a rare and possibly multistep process. The potential generation of a recombination breakpoint (RB) at locus 76 (RB76) was investigated over time in 10 Ty-1 resistant and 10 nearly isogenic susceptible tomato plants co-inoculated with TYLCV and TYLCSV clones. RB76 could not be detected in the recombinant progeny using the standard PCR/sequencing approach that was previously designed to monitor the emergence of TYLCV-IS76 in Morocco. Using a more sensitive PCR test, RB76 was detected in one resistant and five susceptible plants. The results are consistent with a very low intra-plant frequency of RB76 bearing recombinants throughout the test and support the hypothesis of a rare emergence of TYLCV-IS76. More generally, RBs were more scattered in resistant than in susceptible plants and an unusual RB at position 141 (RB141) was positively selected in the resistant cultivar; interestingly, RB141 bearing recombinants were detected in resistant tomato plants from the field. Scenarios of TYLCV-IS76 pre-emergence are proposed.

Four hundred and eighty brown citrus aphid T. aurantii colonies from ten cohorts were followed and referred from middle of April to end of May in several citrus orchards in the Gharb area during 2006 et 2007 years. This pest would prefer to colonize the S1 and S2 citrus leaves stages but all other studied stages would be predisposed to be also colonized. The colonies of indeterminate foundation were the most important, followed by those founded by the apterous ones (e. g. summer colonies) and also those resulting from alatae one (e. g. spring colonies). Immigration of alates is also discussed. T. aurantii regulation factors are multiple (17 sources) and may act individually or combined. A significante difference of mortality level of T. aurantii colonies was noted and discussed between regulation's origins. Coccinellidae is the most efficient predators of T. aurantii, with A. decempunctata and i (Coleoptera : Coccinellidae). Impact of beneficial such as A. decempunctata, C. septempunctata, A. decempunctata in association with C. septempunctata on aphid regulation is respectively from 5 to 48.33% ; 5 to 16.7%, and 5 to 18.33%. Impact of other regulation’s origins such as temperature and old leaves on aphid mortality is respectively from 8 to 55% and 3.33 to 40%. Others predators such as Aphidoletes Aphidimyza Rond. (Diptera : Cecidomyiidae), Chrysoperla carnea Stephens (Neuroptera : chrysopidae) and Episyrphus balteatus DeGeer (Diptera : Syrphidae), affect also T. aurantii colonies. The impact of theses indigenous beneficial species, acting individually or with ladybird on colony survival is low, except for A. decempunctata in association with E. balteatus with a maximum of 10%., Quatre cent quatre-vingts colonies de pucerons noirs de l’oranger T. aurantii de dix cohortes ont été suivies, référencées et dénombrées de miavril à fin mai dans 10 vergers d’agrumes (Citrus spp.) de la région du Gharb durant les années 2006 et 2007. L’origine des colonies de ce ravageur qui colonise principalement certains stades des feuilles est la plupart du temps indéterminée. Cependant ces colonies peuvent être également formées par des individus aptères (surtout colonies d’été) et ailées (surtout colonies printanières). L’immigration des individus ailés a été discutée ainsi que les facteurs de régulation qui sont au nombre de 17 et agissent individuellement ou de façon conjuguée. Une différence significative du taux de régulation des colonies de T. aurantii a été notée et discutée entre les différentes origines de régulation. Les coccinelles Adalia decempunctata L. et Coccinella septempunctata L. (Coleoptera : Coccinellidae) sont les prédateurs les plus efficaces contre T. aurantii. L’impact de A. decempunctata représente 5 à 48,33% de l’ensemble de la régulation, il est de 5 à 16,7% pour C. septempunctata, de 5 à 18,33% pour le couple A. decempunctata + C. septempunctata. La température et l’âge des pousses sont aussi des facteurs importants de régulation, et représentent respectivement de 8 à 55% et de 3,33 à 40% dans la limitation des colonies de T. aurantii. D’autres prédateurs affectent également les colonies de T. aurantii, tels que Aphidoletes Aphidimyza Rond. (Diptera : Cecidomyiidae), Chrysoperla carnea Stephens (Neuroptera : chrysopidae) et Episyrphus balteatus DeGeer (Diptera : Syrphidae). L’effet de ces espèces indigènes, qui agissent individuellement ou avec les coccinelles, reste faible, excepté pour le couple A. decempunctata + E. balteatus avec un maximum de 10 %., Smaili Moulay Chrif, Blenzar Abdelali, Boutaleb Abdelmalek Joutei. Étude prospective de la fondation, de l’immigration et des facteurs de mortalité des colonies de pucerons noirs de l’oranger Toxoptera aurantii Boyer de Fonscolombe (Hemiptera : Aphididae) au nord du Gharb. In: Ecologia mediterranea, tome 35,2009. pp. 5-18.

BGPI : équipe 2; Recombination events are frequently inferred from the increasing number of sequenced viral genomes, but their impact on natural viral populations has rarely been evidenced. TYLCV-IS76 is a recombinant (Begomovirus, Geminiviridae) between the Israel strain of tomato yellow leaf curl virus (TYLCV-IL) and the Spanish strain of tomato yellow leaf curl Sardinia virus (TYLCSV-ES) that was generated most probably in the late 1990s in southern Morocco (Souss). Its emergence in the 2000s coincided with the increasing use of resistant tomato cultivars bearing the Ty-1 gene, and led eventually to the entire displacement of both parental viruses in the Souss. Here, we provide compelling evidence that this viral population shift was associated with selection of TYLCV-IS76 viruses in tomato plants and particularly in Ty-1-bearing cultivars. Real-time quantitative PCR (qPCR) monitoring revealed that TYLCV-IS76 DNA accumulation in Ty-1-bearing plants was significantly higher than that of representatives of the parental virus species in single infection or competition assays. This advantage of the recombinant in Ty-1-bearing plants was not associated with a fitness cost in a susceptible, nearly isogenic, cultivar. In competition assays in the resistant cultivar, the DNA accumulation of the TYLCV-IL clone - the parent less affected by the Ty-1 gene in single infection - dropped below the qPCR detection level at 120 days post-infection (p. i.) and below the whitefly vector (Bemisia tabaci) transmissibility level at 60 days p. i. The molecular basis of the selective advantage of TYLCV-IS76 is discussed in relation to its non-canonical recombination pattern, and the RNA-dependent RNA polymerase encoded by the Ty-1 gene.

Aphid control in Moroccan citrus orchards is based mainly on carbamate and neonicotinoid sprays, especially methomyl and imidacloprid. The extensive use of these insecticides may have side effects on natural enemies and environment quality and raises human health concerns. This research aimed to assess the control of aphids with insecticidal soap, kaolin and augmentative biological control using the indigenous predator Adalia decempunctata L. (Coleoptera: Coccinellidae). The insecticides were applied and the predators were released in April 2009 and 2010. Under field experimentation, the methomyl and imidacloprid foliar pulverization were very effective against aphids. In contrast, the insecticidal soap and kaolin application were less efficient while A. decempunctata adults were effective only in the first week after release. The side effects on beneficial insects were also assessed and discussed. The possibility of employing A. decempunctata in an integrated pest management package in citrus groves is discussed in relation to effectiveness and side effects on beneficial arthropods.