Dr. Mohammed Ater is a professor in the Department of Biology of the Faculty of Sciences of Abdelmalek Essaâdi University (Tetouan). This work concerns the general theme of the conservation and enhancement of plant biodiversity. He has worked particularly on the assessment of plant tolerance to heavy metals for applications in phytoremediation, the recognition and evaluation of genetic resources of underutilized and neglected crops and the agrodiversity of traditional agroecosystems.
The Science of the total environment, Jan 15, 2013
Cannabis, also called marihuana or hemp, is a wind-pollinated plant that produces hundreds of flo... more Cannabis, also called marihuana or hemp, is a wind-pollinated plant that produces hundreds of flowers on large inflorescences. It is also one of the oldest psychoactive plants known to humanity. Morocco has become one of the main producers of Cannabis resin (hashish), primarily supplying the European market. The aim of this paper is to ascertain whether the atmospheric monitoring of Cannabis pollen can play a role, from a criminological point of view, in the surveillance of Cannabis cultivation in the area of Tetouan (NW Morocco) as well as to estimate pollen emission so that the sensitive population can be warned about the allergic diseases that its pollen can cause. Aerobiological samplings were made with the aid of a Hirst type volumetric trap (Hirst, 1952), which worked uninterruptedly during a 3-year period (2008-2010) according to the methodology proposed by the Spanish Aerobiology Network, the REA. Cannabis pollen was present in the atmosphere of Tetouan mainly from early Apr...
... MATERIALS AND METHODS The Study Clones Forty five fig clones were collected in northern Moroc... more ... MATERIALS AND METHODS The Study Clones Forty five fig clones were collected in northern Morocco and planted in a varietal collection at the AIN TAOUJDATE INRA (Experimental Station). Every cultivar is represented by three trees. ...
To assess the genetic diversity in Moroccan cultivated olive, Olea europaea L. subsp. europaea, w... more To assess the genetic diversity in Moroccan cultivated olive, Olea europaea L. subsp. europaea, we performed molecular analysis of olive trees sampled in four geographic zones representing all areas of traditional olive culture. The analysis of 215 trees using 15 simple sequence repeat (SSR) loci revealed 105 alleles distributed among 60 SSR profiles. The analysis of chloroplast deoxyribonucleic acid polymorphism for these 60 olive genotypes allowed to identify four chlorotypes: 42 CE1, one CE2, nine COM1 and eight CCK. Among the 60 SSR profiles, 52 corresponded to cultivated olive trees for which neither denomination nor characterisation is available. These local olive genotypes displayed a spatial genetic structuring over the four Moroccan geographic zones (northwest, north centre, Atlas and southwest), as pairwise Fst values ranged from 0.0394 to 0.1383 and varied according to geographic distance. As single alleles detected in local olive were also observed in Moroccan oleaster populations, results suggest that plant material was mainly selected from indigenous populations. The assumption that Picholine marocaine cultivar is a multi-clonal cultivar was not supported by our data because we found a single genotype for 112 olive trees representing 31 to 93% of the olives sampled locally in the 14 different areas. Picholine marocaine and the few other named cultivars do not seem to belong to the same gene pools as the unnamed genotypes cultivated only locally. The situation is paradoxical: a substantial genetic diversity in Moroccan olive germplasm, probably resulting from much local domestication, but a single cultivar is predominant.
Patterns of variation in inflorescence and spikelet morphology and in allozyme markers were studi... more Patterns of variation in inflorescence and spikelet morphology and in allozyme markers were studied within and among six fields of sorghum sampled from different areas in Northwestern Morocco. Substantial variation for both types of markers is found within fields. Significant differentiation among fields occurs for both types of traits, with 63% of morphological variation and 20% of allozyme variation expressed among fields. Discrepancies between allozyme studies based on germplasm accessions conserved ex situ and this and other studies involving in situ sampling underline the need to use appropriate sampling schemes for assessing the patterns of genetic variation of local landraces.
Variation in plant elemental composition (Ni, Ca, Mg, Mg/Ca ratio) in relation to soil compositio... more Variation in plant elemental composition (Ni, Ca, Mg, Mg/Ca ratio) in relation to soil composition was investigated in a poorly studied ultramafic area in the north of Morocco. A total of 142 leaf samples representing 36 species from 9 sites (5 ultramafic and 4 normal soils from adjacent areas) were analysed. The soil was richer in Mg and Ni and had a higher Mg/Ca ratio in the ultramafic sites than in the control sites, and these differences were qualitatively reflected in the average mineral composition of the plants. However, there were considerable differences in mineral composition among species within serpentinic sites, indicating that species with contrasting mineral nutrition strategies can cope with the mineral element imbalance characteristic of ultramafic soils. Particularly noteworthy was the finding that species with high requirements of Ca are not excluded from serpentinic soils. In view of their high responsiveness to soil nickel and magnesium concentration, Dittrichia viscosa and Lavandula dentata are proposed as bioindicators of these elements in the soil in the Rif area. By contrast, two local serpentine endemics, Halimium atriplicifolium and Notholaena marantae were excluders of nickel and magnesium.
The main objective of this study is to evaluate the agrodiversity in the traditional agrosystems ... more The main objective of this study is to evaluate the agrodiversity in the traditional agrosystems of the Rif. The local varieties, marginal crops, neglected and or underused natural resources and the traditional knowledge were inventoried. This study is based on inquiries to farmers and grains storekeepers. The fruit varieties are remarkable in number so that arboriculture constitutes an essential element of the Rif agrosystems. These various crops are represented by local varieties, which are cultivated in well specified areas with limited exchanges among different regions. Fruit trees are harvested from natural areas. The protection of biodiversity can only be a result of persistence and the maintenance of this agricultural richness. Ecological damage and risks to agriculture such as introduction of selected varieties and the culture of cannabis can be avoided by e valuation and exploitation of this rich genetic heritage.
Grape diversity present in Morocco and the part of this diversity used nowadays are poorly docume... more Grape diversity present in Morocco and the part of this diversity used nowadays are poorly documented. In order to choose diversified genotypes, to select them so that their agronomic interest will be tested, a group of 21 autochthonous cultivars preserved in the germplasm collections of SODEA and 18 Moroccan cultivars from “Domaine de Vassal” INRA grape collection was compared to a group of cultivars from neighbouring countries (Algeria and Tunisia), and from a core collection optimizing simple sequence repeat (SSR) allelic diversity of grape. Data from 20 nuclear and 3 chloroplastic SSR markers were obtained for this set of 211 cultivars. A total of 156 alleles (mean of 7.8 alleles per locus) were detected for the nSSRs and 7 alleles for the cpSSR in the Moroccan group. Chlorotype diversity in Moroccan and Algerian group were similar, but slightly lower than in the Tunisian group and the core collection. Similarly, the nSSR diversity was high in the core collection and low in the Moroccan and the Algerian groups compared to the two other groups. Clustering of cultivars based on nSSR data reflected their geographical origin and, to a certain extent, the use of the cultivars. The specificity of the Moroccan plant material was attested by the Bayesian analysis using Structure, while differences of the core collection were clearly revealed both by the Bayesian and a multivariate analysis. These results confirm the differentiation of the material from Maghreb and more specifically of Moroccan material, having evolved independently from Europe.
The study of the genetic variability of the Moroccan landraces of sorghum constitutes a necessary... more The study of the genetic variability of the Moroccan landraces of sorghum constitutes a necessary step that can be exploited in the programs of improvement and valorisation of this marginalized species. The aim of this investigation is to evaluate the variability of sorghum populations and to establish their phylogenetic relations using RAPD and ISSR markers. Sampling was taken in 33 fields of northern regions where this species is most cultivated. Individual plants (398) were collected in 13, 11, 5, and 4 fields of Larache, Tangier, Chefchaouen, and Tetouan, respectively. Thirty-eight RAPD primers and four ISSR primers were used. The percentage of polymorphic fragments revealed with ISSR (98%) is higher than the one revealed with RAPD (85%). The level of the variability obtained through the two techniques is very high. Nevertheless, ISSR markers revealed more diversity than RAPD (0.995±0.0060.995±0.006 against 0.946±0.0310.946±0.031). The classification based on Jaccard's similarity index distinguished the totality of fields. Data analysis revealed a genetic structure that is closely related to the micro-geographical repartition of the different fields. To cite this article: L. Medraoui et al., C. R. Biologies 330 (2007).L'étude de la variabilité génétique des variétés-populations de sorgho grain marocain constitue une étape nécessaire à exploiter dans les programmes d'amélioration et de valorisation de cette céréale marginalisée. L'objectif de cette étude est d'évaluer la variabilité des populations de sorgho et d'établir leurs relations phylogénétiques via les marqueurs RAPD et ISSR. L'échantillonnage a été réalisé dans 33 champs au niveau de la région nord du Maroc, où cette espèce est largement cultivée. Il concerne 398 individus collectés respectivement dans 13, 11, 5 et 4 champs de Larache, Tanger, Chefchaouen et Tétouan. Trente-huit amorces RAPD et quatre amorces ISSR ont été utilisées. Le pourcentage de polymorphisme révélé avec ISSR (98%) est supérieur à celui révélé avec RAPD (85%). Le niveau de diversité obtenu par les deux techniques est élevé. Néanmoins, l'ISSR a montré plus de diversité que le RAPD (0,995±0,0060,995±0,006, contre 0,946±0,0310,946±0,031). La classification selon l'indice de similarité de Jaccard a permis la distinction de la totalité des champs étudiés. L'analyse des données a révélé une structure génétique qui est étroitement liée à la répartition micro-géographique des différents champs. Pour citer cet article : L. Medraoui et al., C. R. Biologies 330 (2007).
The Science of the total environment, Jan 15, 2013
Cannabis, also called marihuana or hemp, is a wind-pollinated plant that produces hundreds of flo... more Cannabis, also called marihuana or hemp, is a wind-pollinated plant that produces hundreds of flowers on large inflorescences. It is also one of the oldest psychoactive plants known to humanity. Morocco has become one of the main producers of Cannabis resin (hashish), primarily supplying the European market. The aim of this paper is to ascertain whether the atmospheric monitoring of Cannabis pollen can play a role, from a criminological point of view, in the surveillance of Cannabis cultivation in the area of Tetouan (NW Morocco) as well as to estimate pollen emission so that the sensitive population can be warned about the allergic diseases that its pollen can cause. Aerobiological samplings were made with the aid of a Hirst type volumetric trap (Hirst, 1952), which worked uninterruptedly during a 3-year period (2008-2010) according to the methodology proposed by the Spanish Aerobiology Network, the REA. Cannabis pollen was present in the atmosphere of Tetouan mainly from early Apr...
... MATERIALS AND METHODS The Study Clones Forty five fig clones were collected in northern Moroc... more ... MATERIALS AND METHODS The Study Clones Forty five fig clones were collected in northern Morocco and planted in a varietal collection at the AIN TAOUJDATE INRA (Experimental Station). Every cultivar is represented by three trees. ...
To assess the genetic diversity in Moroccan cultivated olive, Olea europaea L. subsp. europaea, w... more To assess the genetic diversity in Moroccan cultivated olive, Olea europaea L. subsp. europaea, we performed molecular analysis of olive trees sampled in four geographic zones representing all areas of traditional olive culture. The analysis of 215 trees using 15 simple sequence repeat (SSR) loci revealed 105 alleles distributed among 60 SSR profiles. The analysis of chloroplast deoxyribonucleic acid polymorphism for these 60 olive genotypes allowed to identify four chlorotypes: 42 CE1, one CE2, nine COM1 and eight CCK. Among the 60 SSR profiles, 52 corresponded to cultivated olive trees for which neither denomination nor characterisation is available. These local olive genotypes displayed a spatial genetic structuring over the four Moroccan geographic zones (northwest, north centre, Atlas and southwest), as pairwise Fst values ranged from 0.0394 to 0.1383 and varied according to geographic distance. As single alleles detected in local olive were also observed in Moroccan oleaster populations, results suggest that plant material was mainly selected from indigenous populations. The assumption that Picholine marocaine cultivar is a multi-clonal cultivar was not supported by our data because we found a single genotype for 112 olive trees representing 31 to 93% of the olives sampled locally in the 14 different areas. Picholine marocaine and the few other named cultivars do not seem to belong to the same gene pools as the unnamed genotypes cultivated only locally. The situation is paradoxical: a substantial genetic diversity in Moroccan olive germplasm, probably resulting from much local domestication, but a single cultivar is predominant.
Patterns of variation in inflorescence and spikelet morphology and in allozyme markers were studi... more Patterns of variation in inflorescence and spikelet morphology and in allozyme markers were studied within and among six fields of sorghum sampled from different areas in Northwestern Morocco. Substantial variation for both types of markers is found within fields. Significant differentiation among fields occurs for both types of traits, with 63% of morphological variation and 20% of allozyme variation expressed among fields. Discrepancies between allozyme studies based on germplasm accessions conserved ex situ and this and other studies involving in situ sampling underline the need to use appropriate sampling schemes for assessing the patterns of genetic variation of local landraces.
Variation in plant elemental composition (Ni, Ca, Mg, Mg/Ca ratio) in relation to soil compositio... more Variation in plant elemental composition (Ni, Ca, Mg, Mg/Ca ratio) in relation to soil composition was investigated in a poorly studied ultramafic area in the north of Morocco. A total of 142 leaf samples representing 36 species from 9 sites (5 ultramafic and 4 normal soils from adjacent areas) were analysed. The soil was richer in Mg and Ni and had a higher Mg/Ca ratio in the ultramafic sites than in the control sites, and these differences were qualitatively reflected in the average mineral composition of the plants. However, there were considerable differences in mineral composition among species within serpentinic sites, indicating that species with contrasting mineral nutrition strategies can cope with the mineral element imbalance characteristic of ultramafic soils. Particularly noteworthy was the finding that species with high requirements of Ca are not excluded from serpentinic soils. In view of their high responsiveness to soil nickel and magnesium concentration, Dittrichia viscosa and Lavandula dentata are proposed as bioindicators of these elements in the soil in the Rif area. By contrast, two local serpentine endemics, Halimium atriplicifolium and Notholaena marantae were excluders of nickel and magnesium.
The main objective of this study is to evaluate the agrodiversity in the traditional agrosystems ... more The main objective of this study is to evaluate the agrodiversity in the traditional agrosystems of the Rif. The local varieties, marginal crops, neglected and or underused natural resources and the traditional knowledge were inventoried. This study is based on inquiries to farmers and grains storekeepers. The fruit varieties are remarkable in number so that arboriculture constitutes an essential element of the Rif agrosystems. These various crops are represented by local varieties, which are cultivated in well specified areas with limited exchanges among different regions. Fruit trees are harvested from natural areas. The protection of biodiversity can only be a result of persistence and the maintenance of this agricultural richness. Ecological damage and risks to agriculture such as introduction of selected varieties and the culture of cannabis can be avoided by e valuation and exploitation of this rich genetic heritage.
Grape diversity present in Morocco and the part of this diversity used nowadays are poorly docume... more Grape diversity present in Morocco and the part of this diversity used nowadays are poorly documented. In order to choose diversified genotypes, to select them so that their agronomic interest will be tested, a group of 21 autochthonous cultivars preserved in the germplasm collections of SODEA and 18 Moroccan cultivars from “Domaine de Vassal” INRA grape collection was compared to a group of cultivars from neighbouring countries (Algeria and Tunisia), and from a core collection optimizing simple sequence repeat (SSR) allelic diversity of grape. Data from 20 nuclear and 3 chloroplastic SSR markers were obtained for this set of 211 cultivars. A total of 156 alleles (mean of 7.8 alleles per locus) were detected for the nSSRs and 7 alleles for the cpSSR in the Moroccan group. Chlorotype diversity in Moroccan and Algerian group were similar, but slightly lower than in the Tunisian group and the core collection. Similarly, the nSSR diversity was high in the core collection and low in the Moroccan and the Algerian groups compared to the two other groups. Clustering of cultivars based on nSSR data reflected their geographical origin and, to a certain extent, the use of the cultivars. The specificity of the Moroccan plant material was attested by the Bayesian analysis using Structure, while differences of the core collection were clearly revealed both by the Bayesian and a multivariate analysis. These results confirm the differentiation of the material from Maghreb and more specifically of Moroccan material, having evolved independently from Europe.
The study of the genetic variability of the Moroccan landraces of sorghum constitutes a necessary... more The study of the genetic variability of the Moroccan landraces of sorghum constitutes a necessary step that can be exploited in the programs of improvement and valorisation of this marginalized species. The aim of this investigation is to evaluate the variability of sorghum populations and to establish their phylogenetic relations using RAPD and ISSR markers. Sampling was taken in 33 fields of northern regions where this species is most cultivated. Individual plants (398) were collected in 13, 11, 5, and 4 fields of Larache, Tangier, Chefchaouen, and Tetouan, respectively. Thirty-eight RAPD primers and four ISSR primers were used. The percentage of polymorphic fragments revealed with ISSR (98%) is higher than the one revealed with RAPD (85%). The level of the variability obtained through the two techniques is very high. Nevertheless, ISSR markers revealed more diversity than RAPD (0.995±0.0060.995±0.006 against 0.946±0.0310.946±0.031). The classification based on Jaccard's similarity index distinguished the totality of fields. Data analysis revealed a genetic structure that is closely related to the micro-geographical repartition of the different fields. To cite this article: L. Medraoui et al., C. R. Biologies 330 (2007).L'étude de la variabilité génétique des variétés-populations de sorgho grain marocain constitue une étape nécessaire à exploiter dans les programmes d'amélioration et de valorisation de cette céréale marginalisée. L'objectif de cette étude est d'évaluer la variabilité des populations de sorgho et d'établir leurs relations phylogénétiques via les marqueurs RAPD et ISSR. L'échantillonnage a été réalisé dans 33 champs au niveau de la région nord du Maroc, où cette espèce est largement cultivée. Il concerne 398 individus collectés respectivement dans 13, 11, 5 et 4 champs de Larache, Tanger, Chefchaouen et Tétouan. Trente-huit amorces RAPD et quatre amorces ISSR ont été utilisées. Le pourcentage de polymorphisme révélé avec ISSR (98%) est supérieur à celui révélé avec RAPD (85%). Le niveau de diversité obtenu par les deux techniques est élevé. Néanmoins, l'ISSR a montré plus de diversité que le RAPD (0,995±0,0060,995±0,006, contre 0,946±0,0310,946±0,031). La classification selon l'indice de similarité de Jaccard a permis la distinction de la totalité des champs étudiés. L'analyse des données a révélé une structure génétique qui est étroitement liée à la répartition micro-géographique des différents champs. Pour citer cet article : L. Medraoui et al., C. R. Biologies 330 (2007).
Uploads
Papers by Ater Mohammed