Mohamed Neffati

Diversity in Allium ampeloprasum : from small and wild to large and cultivated

Allium ampeloprasum evolved as a complex of different cyto- and morpho-types widely distributed either in the wild or domesticated range of the Mediterranean regions. The assessment of genetic and phylogenetic relationships between Tunisian A. ampeloprasum and specimens from different origins and with variable degree of domestication can promote conservation and breeding. Minisatellite M13, microsatellite (GTG)5 and nucleotide sequence analysis of the internal transcribed spacer region (ITS) were used to assess DNA polymorphism and genetic diversity. M13 and (GTG)5 molecular markers efficiently discriminated A. ampeloprasum gene-pool from A. sativum. Geographic genetic patterns of variation of the wild gene-pool were not detected. However, domesticated A. ampeloprasum (great headed garlic, kurrat and leek) clustered consistently within the ampeloprasum group. A. sativum was found to be closer to A. ampeloprasum than A. fistulosum and A. schoenoprasum. A high number of single point mutations (SNPs) was recorded over the ITS1-2 spacer sequence. Most of these SNPs were heterozygous only in great headed garlic. It is inferred that heterozygosity played the major role in promoting great headed garlic domestication. Thus, great headed garlic adaptation to horticultural conditions along with its yield trait sizes are mainly associated to heterozygosity rather than to polyploidy.

Chemical Variability of Artemisia herba-alba Asso Growing Wild in Semi-arid and Arid Land (Tunisia)

Abstract Twenty-six oil samples were isolated by hydrodistillation from aerial parts of Artemisia herba-alba Asso growing wild in Tunisia (semi-arid land) and their chemical composition was determined by GC(RI), GC/MS and 13C-NMR. Various compositions were observed, dominated either by a single component (α-thujone, camphor, chrysanthenone or trans-sabinyl acetate) or characterized by the occurrence, at appreciable contents, of two or more of these compounds. These results confrmed the tremendous chemical variability of A. herba-alba.

Fruit morphological descriptors as a tool for discrimination of Daucus L. germplasm

Fruits present major morphological characters used to define genera and species within the Apiaceae. Northern Africa represents a major center of diversity of Daucus, with Tunisia containing at least 12 species and six subspecies. We assessed 14 mature fruit characters from the Daucus L. germplasm collection at the National Gene Bank of Tunisia. Quantification of variability for each character was investigated using the standardized Shannon–Weaver diversity index (H′). Diversity was established by factorial analysis of correspondence and cluster analysis. The computing H′ index ranged from 0.31 for stylopodium shape to a maximum of 0.81 for spine shape. A mean diversity index for all traits recorded across all populations averaged 0.58 indicating existence of an important genetic diversity within the collection. Multivariate analysis of factorial correspondence and cluster analysis on morphological descriptors permitted the subdivision of the Daucus collection into five distinct groups including one single accession group, two groups with six accessions, one group of nine accessions and one large group with 81 accessions corresponding each one to a species among Daucus except the large group corresponding to D. carota and D. capillifolius. The grouping of populations did not reflect bioclimatic and geographic patterns, suggesting adaptation of populations to local environments. Of equal importance, our study shows the effectiveness of fruit characters alone to identify species in this collection of Daucus.

Differential responses to drought stress in leaves and roots of wild jujube, Ziziphus lotus

The aim of this study was to investigate the effects of drought stress induced by polyethylene glycol-6000 in wild jujube, Ziziphus lotus. One-month-old, hydroponically grown seedlings were subjected to three treatments, i.e. normal watering (−0.2xa0MPa), moderate (−1.2xa0MPa) and severe (−2.1xa0MPa) drought stress for 14xa0days under controlled climatic conditions. Plant growth was markedly reduced with increasing osmotic stress. The shoot water potential (Ψw) and leaf relative water content followed similar patterns and significantly decreased with increasing osmolality of solutions. As a consequence of drought, contents in proline and soluble sugars were found to be more elevated in leaves than in roots. The level of lipid peroxidation in terms of malonyldialdehyde contents increased in both leaves and roots of drought-stressed plants. Wild jujube displayed higher activities of antioxidant enzymes in the roots than in the leaves. Catalase and guaiacol peroxidase activities increased significantly in drought-stressed roots, whereas ascorbate peroxidase activity showed a slight decline with no significant changes. These findings suggest that Z. lotus was able to adapt to severe drought stress by accumulation of compatible solutes and by activation of free radical-scavenging enzymes. Overall, defence mechanisms in Z. lotus against oxidative stress are organized differently in plant tissues, with higher solute accumulation in leaves and increased activity of antioxidants in roots, during drought stress.

The Essential Oil From Artemisia herba-alba Asso Cultivated in Arid Land (South Tunisia)

Abstract Seedlings of Artemisia herba-alba Asso collected from Kirchaou area were transplanted in an experimental garden near the Institut des Régions Arides of Médenine (Tunisia). During three years, the aerials parts were harvested (three levels of cutting, 25%, 50% and 75% of the plant), at full blossom and during the vegetative stage. The essential oil was isolated by hydrodistillation and its chemical composition was determined by GC(RI) and 13C-NMR. With respect to the quantity of vegetable material and the yield of hydrodistillation, it appears that the best results were obtained for plants cut at 50% of their height and during the full blossom. The chemical composition of the essential oil was dominated by β-thujone, α-thujone, 1,8-cineole, camphor and trans-sabinyl acetate, irrespective of the level of cutting and the period of harvest. It remains similar to that of plants growing wild in the same area.

Influence of drying time and process on Artemisia herba-alba Asso essential oil yield and composition

Abstract The essential oil content of Artemisia herba-alba Asso decreased along the drying period from 2.5 % to 1.8 %. Conversely, the composition of the essential oil was not qualitatively affected by the drying process. The same principle components were found in all essential analyzed such as α-thujone (13.0 – 22.7 %), β-thujone (18.0 – 25.0 %), camphor (8.6 - 13 %), 1,8-cineole (7.1 – 9.4 %), chrysanthenone (6.7 – 10.9 %), terpinen-4-ol (3.4 – 4.7 %). Quantitatively, during the air-drying process, the content of some components decreased slightly such as α-thujone (from 22.7 to 15.9 %) and 1,8-cineole (from 9.4 to 7.1 %), while the amount of other compounds increased such as chrysanthenone (from 6.7 to 10.9 %), borneol (from 0.8 to 1.5 %), germacrene-D (from 1.0 to 2.4 %) and spathulenol (from 0.8 to 1.5 %). The chemical composition of the oil was more affected by oven-drying the plant material at 35°C. α-Thujone and β-thujone decreased to 13.0 %and 18.0 %respectively, while the percentage of camphor, germacrene-D and spathulenol increased to 13.0 %, 5.5 %and 3.7 %, respectively.

Variation in Volatiles of Astragalus gombiformis Pomel

The essential oils obtained by hydrodistillation (Clevenger apparatus) from aerial parts of Astragalus gombiformis were analysed by gas chromatography coupled with mass spectrometry (GC/MS). This study showed that the A. gombiformis essential oils are complex mixtures of important natural compounds, which varied qualitatively and quantitatively between cultivated and wild plants and between phenological stages of development. All analysed oils are characterized by the constant presence of phytol, 6,10,14-trimethyl-2-pentadecanone, 4-terpineol, and γ-terpinene. This study is the fi rst report on the chemical composition of essential oils from A. gombiformis and indicates that these oils should be more studied.

Allium Species, Ancient Health Food for the Future?

Allium is the largest and the most important representative genus of the Alliaceae family that comprises 700 species, widely distributed in the northern hemisphere, North America, North Africa, Europe and Asia (Tsiaganis et al., 2006). Besides the well known garlic and onion, several other species are widely grown for culinary use and for folk medicine including leek (Allium porrum L.), scallion (Allium fistulosum L.), shallot (Allium ascalonicum Hort.), wild garlic (Allium ursinum L.), garlic (Allium sativum) and onion (Allium cepa) (Lanzotti, 2006; Tsiaganis et al., 2006). Its consumption is attributed to several factors, mainly heavy promotion that links flavour and health. The powerful and unusual flavors of many of these plants and their possible nutritional impact and medical applications have attracted the attention of plant physiologists, chemists, nutritionists, and medical researchers (Graham and Graham, 1987). Allium roseum is a very polymorphous, widespread species that is represented by 12 different taxa: 4 varieties, 4 subvarieties and 4 forms in North Africa (Cuenod, 1954; Le Floc’h, 1983). In Tunisia, the same authors mentioned the presence of only three varieties: var. grandiflorum, var. perrotii and var. odoratissimum. The odoratissimum variety is an endemic taxon in North Africa and a perennial spontaneous weed (Cuenod, 1954). Its flowering stem is about 30-60 cm, leaves are fleshy and very small, flowers are wide, rosy or white coloured and its odour is eyelet (Jendoubi et al., 2001). In Southern Tunisia, local people on the extension area where A. roseum or rosy garlic occurs have extensively developed uses for this species both as a cooking ingredient and a sauce (Najjaa et al., 2011a). A. roseum leaves are the main edible part, with a distinctive pungent odour and strong flavour. Besides its culinary use, rosy garlic is also used in folk medicine. Le Floc’h (1983) reported its use for the treatment of headaches and rheumatism. It is also used for the treatment of bronchitis, colds as an inhalation, fever diminution and as an appetizer. While several studies have provided information about A. roseum, detailed studies documenting compositional, nutritional and functional properties are very limited, if not

Medicinal and Aromatic Plants of the World - Africa Volume 3

Natural substances of plant origin, have been used by man from the very early times of civilizations. Traditional Medicine (TM), a heritage of Africa, is still servicing approx. 80% of the population of this huge continent comprizing 55 countries, 800 languages and an unmeasurable wealth of plant diversity. The continent with a varied flora of an estimated 68,000 plant species is home to about 35,000 endemic species (Cunningham A, African medicinal plants. Setting priorities at the interface between conservation. UNESCO, Paris, 1993), growing in seven centers of endemism. Africa’s not yet fully explored medicinal plant resources frequently come into the forefront of interest. The recent upsurge is witnessed by the fact that ca. 60% of all recent publications on African medicinal plants, appeared during the last decade. There is a tremendous potential for developing new crops and new products. Research into MAPs seem to offer a nearly unlimited scope for exploration. The ongoing screening for the biological activity of MAPs is also broad and covers several important health related aspects including antimalarial and other antiprotozoal products, anti-proliferative potential, anti-inflammatory and analgesic activities, anti-diabetes activity antioxidant activity and activity on the reproductive cardiovascular and central nervous systems, etc. Despite of this marked recent increase, Africa is lagging behind Europe and Asia in terms of the number of products that have been commercialized and the percentage of flora utilized for international trade. The growing demand on resources, however, has resulted, in some cases, the overexploitation, the occasional local disappearance of favored sources of botanicals and have reduced the diversity of species. By elaborating international and national standards of sustainability, these dangers should be either eased or eradicated. Domestication of wild-crafted species can also contribute to preserve the genetic resources and to reduce the sometimes imminent threats of extinction. The recent initiative to develop national and ultimately an African Herbal Á. Máthé (*) Faculty of Agriculture and Food Science, University of West Hungary, Mosonmagyaróvár, Hungary e-mail: acatius2005@gmail.com M. Neffati • H. Najjaa Arid Zone Research Institute, 4119 Médenine, Tunisia e-mail: neffati.mohamed@ira.rnrt.tn; hanen.najjaa@yahoo.fr

Multivariate analysis of morphological diversity among closely related Daucus species and subspecies in Tunisia

Abstract The genus Daucus includes about 20–25 species worldwide. Northern Africa represents a major center of diversity of Daucus, with Tunisia thought to contain 11 species and seven subspecies. The greatest taxonomic problems, however, and the greatest economic importance relative to immediate use in breeding, is in a group of species and subspecies in the Daucus carota L. clade, all containing 2nxa0=xa018 chromosomes. We assessed morphological diversity from a Daucus L. germplasm collection of nine individuals each from 45 accessions (405 individuals in total), at the National Gene Bank of Tunisia, of the following wild and one cultivated members of this clade: D. carota subsp. capillifolius (Gilli) Arbizu, D. carota subsp. carota, D. carota subsp. gummifer (Syme) Hook. f., D. carota subsp. sativus (Hoffm.) Arcangeli (cultivated), D. sahariensis Murb., and putative hybrids of D. carota subsp. carota and subsp. capillifolius. A prior study showed the effectiveness of fruit characters to identify several species and subspecies in the collection, but distinction between some closely related D. carota subspecies was difficult. In order to resolve the taxonomic classification, we tested 32 quantitative and qualitative morphological characters from leaves, stems and flowers on a field collection of 45 accessions corresponding to the different species/subspecies. The Shannon–Weaver diversity (H’) index was used to study the phenotypic diversity. The estimated H’ ranged from monomorphic for umbel type, position of involucral bracts on primary umbel, anther color, and symmetry of peripheral flowers to highly polymorphic for other traits. The highest (0.98) and the lowest (0.26) H’ values were recorded for flowering pattern within plants and foliage coverage. Multivariate analyses of principal components and dendrograms of all data and canonical discriminate analysis of the quantitative data supported the subdivision of the Daucus collection into five groups with various degrees of distinctness: (1) D. sahariensis, (2) D. carota subsp. capillifolius, (3) D. carota subsp. carota, very similar to (4) D. carota subsp. gummifer, and (5) D. carota subsp. sativus intergrading with putative hybrids between D. carota subsp. capillifolius and D. carota subsp. carota. Individual character state distribution plots provide useful characters and insights into taxonomic problems in the D. carota clade that we here discuss in reference to ongoing molecular studies in Daucus.