Molecular Characterization and Study of Genetic Relationships among local Cultivars of the Moroccan fig (Ficus carica L.) using Microsatellite and ISSR Markers

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

Effet du cultivar, du prétraitement et de la technique de séchage sur quelques paramètres physico-chimiques des figues séchées de sept cultivars locaux du figuier (Ficus carica L.) au Maroc

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Effets biocides des alcaloïdes, des saponines et des flavonoïdes extraits de Capsicum frutescens L. (Solanaceae) sur Bemisia tabaci (Gennadius) (Homoptera : Aleyrodidae)

Biocide effects of alkaloids, saponins and flavonoids extracted from Capsicum frutescens L. (Solanaceae) on Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae). In an attempt to elaborate a strategy of integrated pest management on vegetable crops in Morocco, insecticidal activities of alkaloids, saponins and flavonoids extracted from Capsicum frutescens L. fruits against eggs and adults of Bemisia tabaci infesting tomato plants, Lycopersicon esculentum Mill. var. Daniella, were carried out under controlled conditions. Alkaloids, saponins and flavonoids, dissolved in ethanol at 1%, were tested at 0, 5, 10 and 20 g.l-1. The three compounds affected egg and adult survival, significantly. The mortality of embryo and adult varied according to the compound considered and for each compound according to concentration and exposure duration. For eggs, the corrected mortality varied from 35 to 59% for alkaloids, 14 to 31% for saponins and 10 to 14% for flavonoids. In adults, the mortalities were spread from 29% to 86%, 14 to 48% and 6 to 29% with alkaloids, saponins and flavonoids, respectively. Significant correlation between egg and adult mortality, due to the compounds tested, were observed. However, eggs required higher concentrations than adults; the LC50 was 13.78 vs. 6.83 g.l-1 for alkaloids, 98.63 vs. 32.28 g.l-1 for saponins and nontoxic vs. 120.65 g.l-1 for the flavonoids. Therefore, alkaloids were shown more effective against B. tabaci than saponins or flavonoids. However, the LT50 estimated for compounds, killing more than 50% of the population studied, was sufficient for viruliferous adults to inoculate TYLCV to plants before they died. The use of these compounds in integrated pest management merit further study

The typical RB76 recombination breakpoint of the invasive recombinant tomato yellow leaf curl virus of Morocco can be generated experimentally but is not positively selected in tomato

International audienceTYLCV-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

Emergence of a recombinant Tomato yellow leaf curl virus and displacement of parental-type viruses in Morocco

National audienc

Étude de l’impact du déficit hydrique et azoté sur les infestations de Myzus persicae (Sulzer) dans le verger du pêcher

National audienceThe objective of this work is to develop an integrated and ecological pest management strategy to assess the impact of water and nitrogen resources on Myzus persicae infestations in the peach orchard. The results of the peach aphid impact study showed a significant effect of water and nitrogen availability on the level of green peach aphid infestation. Indeed, the normal fertilization regime (T1=100%) was found to be much more favorable to a prominent development of the aphidian populations, while the regime deficit of 25% in water and nitrogen by contribution to the normal diet (T2=75%) was able to minimize the infestations of the latter. At the same time, the study of the effect of orientation on the infestation of the aphid showed that orientations North, West and South were more infested than that of East. As for the auxiliaries and the ants, the treatment carried out revealed a significant effect on their evolution

Monitoring the dynamics of emergence of a non-canonical recombinant of Tomato yellow leaf curl virus and displacement of its parental viruses in tomato

BGPI : équipe 2 et 6International audienceRecombinant viruses are increasingly being reported but the dynamics of their emergence is rarely documented. A new recombinant Tomato yellow leaf curl virus (TYLCV-IS76) was detected for the first time in 2010 in Southern Morocco (Souss). An original diagnostic tool was needed to fit its unusual recombination profile. Although IS76 was detected following the appearance of Tylc symptoms on tolerant tomato plants, symptoms could not be associated to IS76 or to a synergy with criniviruses. According to infection profiles of Tylc-associated viruses determined on 879 plant samples collected between 1998 and 2014 and a Bayesian inference applied to genomic sequences of representatives of TYLCV, IS76 emerged in Southern Morocco at the end of the 1990s, replaced the parental viruses between 2004 and 2012 in Souss and is spreading towards the North of Morocco. The emergence of IS76 coincides with the increasing use of tolerant cultivars in the 2000s

A recombinant tomato yellow leaf curl virus has replaced its parental viruses in southern Morocco

National audienc