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JOURNAL OF OASIS AGRICULTURE AND SUSTAINABLE DEVELOPMENT

ISSN(p):2724 - 699X | ISSN(e):2724-7007
Journal Papers (29) Details
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Indexed Journal

1 First study of Genetic diversity in watermelon (Citrullus lanatus) germplasm collected from Southern Tunisia using RAPD markers , Elbekkay Mokhtar, Hamadi Hamza, Bekri Tozer, Haddad Mansour and Ferchichi Ali
The genetic diversity in local Tunisian watermelon (Citrullus lanatus) was studied using RAPD markers. Eight watermelon cultivars originating from south of Tunisia and belong to four populations were analysed and compared to two commercial varieties (Giza and Sugar-baby) widely produced in this area. Five of nine RAPD primers generated a total of 86 reproducible bands, 85 of which were polymorphic (98.4%). Cluster analysis of the accessions considered in this study employing RAPD data indicated that commercial varieties are significantly different of all the local cultivars. The relationships among the local cultivars (four populations) showed that Medenine population and the most genotypes of Benguerdane population were grouped together and significantly different from Kebili population. The AMOVA showed significant differentiation between populations (27%). In addition, the data showed clusters according to some fruit characteristics such as fruit shape and fruit weight. This proved that RAPD markers are useful for germplasm discrimination as well as for investigation of patterns of variation in watermelon.
2 First study of Genetic diversity in watermelon (Citrullus lanatus) germplasm collected from Southern Tunisia using RAPD markers , Elbekkay Mokhtar, Hamadi Hamza, Bekri Tozer, Haddad Mansour and Ferchichi Ali
The genetic diversity in local Tunisian watermelon (Citrullus lanatus) was studied using RAPD markers. Eight watermelon cultivars originating from south of Tunisia and belong to four populations were analysed and compared to two commercial varieties (Giza and Sugar-baby) widely produced in this area. Five of nine RAPD primers generated a total of 86 reproducible bands, 85 of which were polymorphic (98.4%). Cluster analysis of the accessions considered in this study employing RAPD data indicated that commercial varieties are significantly different of all the local cultivars. The relationships among the local cultivars (four populations) showed that Medenine population and the most genotypes of Benguerdane population were grouped together and significantly different from Kebili population. The AMOVA showed significant differentiation between populations (27%). In addition, the data showed clusters according to some fruit characteristics such as fruit shape and fruit weight. This proved that RAPD markers are useful for germplasm discrimination as well as for investigation of patterns of variation in watermelon.
3 Mineral fruit composition variation alongside Phoenix dactylifera L. cultivars dependently on geographical origin and agronomic traits , Hamza Hammadi, Jarray Naceur, Yahya Leila and Ferchichi Ali
Date palm gives fruits that make a significant human dietetic through great amounts of different sugars supplement and of minerals. Water, ash and six minerals contents were investigated in dates of 131 individual trees. The geographical effect in mineral content was carried out on tow cultivars, Deglet nour and Alig. New oases of Jerid region, compared to other origins, gave date of Deglet nour with the highest levels of the studied parameters except for the ash and the Calcium contents which were stable between oases. However, old oasis of Jerid region had fruit Alig with the upper levels in phosphorus (0.1 g/100g), sodium (54.76 ppm), magnesium (0.05 g/100g) and iron (0.77 mg/100g); but the lowest in total mineral content (1.75 g/100g) and manganese (0.14 mg/100g). The effect of agronomic traits (maturity period and fruit consistency) was studied basing on 38 different cultivars. Concerning the maturity period, fruits of early ripening cultivars exhibited an elevated concentration in iron (0.87 mg/100g) and calcium (0.024 g/100g) in comparison with those of later maturity cultivars which had the highest ash percent (1.59 g/100g). For the fruit consistency, soft fruits showed the greater Iron content (0.84 mg/100g) but the dry ones exhibited the highest potassium content (0.57 g/100g). These results proposed to consumers that they have to consider the provenance, the fruit consistency and the maturity period which looks as a good indicator for mineral content.
4 Potentiel biotique d’une espèce exotique ravageur du palmier dattier : Oryctes agamemnon (Coleoptera : Scarabaeidae) , Ehsine M’hammed, Belkadhi Mohamed Sadok, Chaieb Mohamed
In Tunisia, particularly in southern regions, the culture of date palms plays an important role, both at socioeconomic and ecological levels. In spite of its importance, this agro-system is still threatened by many species of insects and diseases. Among these phytosanitary problems figure the exotic pest Oryctes agamemnon. This insect causes severe damage on palm tree mainly on the collar and the root system. The aim of this work is to study some parameters of the biotic potential of the insect. A number of ten couples were used in this survey. Follow-up of the experiment under the following conditions (Relative humidity = 40 +/- 6%, Temperature = 28 ° C +/- 2 ° C and a photoperiod: 16/8) allowed to study the reproductive potential, the larval survival rate and the adult lifetime. The follow-up of the experiment shows that the average pre-oviposition period and the average post-oviposition period are 25.3 ± 9.85 and 7.3 ± 5.39 days, respectively. The developmental cycle comprises, the egg, 3 larval stages L1, L2 and L3, prenymph and nymph respectively lasted 13,742 ± 2,011 days, 26,591 ± 3,142 days, 43,361 ± 3,237 days, 137,047 ± 6,132 days, 7,487 ± 0,909 days and 21,390 ± 2,655 days. Survival rates for the various stages ranged from 83.631 to 93.886%. Adults lived on average 55.18 days for males and 60 days for females. The average number of eggs laid per female was 28.7 ± 17.13 with an average fertility rate of 81.184%.
5 Comparison of strains of Nesidiocoris tenuis against Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) under geothermal greenhouses in southern Tunisia , Refki Ettaib, Faouzi Aoun , Besma Assadi, Ali Ben Belgacem , Sabrine Chouikhi
Heated greenhouse cultivation in southern Tunisia constitutes a very important axis of agricultural development. Among the problems that are prejudicial to glasshouse tomato crops heated by geothermal waters, the newly introduced Tuta absoluta insect remains little studied in this agro-ecosystem. Biological means in the context of an integrated fight against this formidable pest to better understand the geothermal sector and contribute to the study of this new problem. The monitoring of a population of a native strain of Nesidiocoris tenuis installed naturally in the geothermal greenhouse and a population of one strain introduced into another greenhouse, showed the performance of the indigenous strain which multiplied rapidly and remained until the end of cult
6 Caractérisation Pomologique de 21 Cultivars Locaux de Figuier (Ficus carica L.) Cultivés dans les Oasis Tunisiennes , Aljane Fateh et Ferchichi Ali
La diversité pomologique du figuier (Ficus carica L.) dans les oasis tunisiennes a été étudiée en utilisant les descripteurs morphologiques. Vingt et un cultivars de figuier originaires des oasis de Kébili, Tozeur et Gafsa ont été analysés et comparés. L'analyse de la variance, l'analyse en composantes principales et l'analyse canonique hiérarchique de caractères liés aux fruits montrent une grande diversité au sein des cultivars étudiés. L'étude de cette diversité de germoplasme du figuier permet de détecter des cas homonymes et synonymies. Certains d'entre eux ont été sélectionnés. Parmi les descripteurs de haut degré de discrimination celles relatifs aux dimensions des fruits, la couleur des fruits, etc. Certains traits morphologiques sont susceptibles d'être utilisés comme descripteurs pour la classification des cultivars de figuier en Tunisie
7 Molecular studies on the date palm (Phoenix dactylifera L.): A review , Hamza Hammadi and Ferchichi Ali
The date palm has some characteristics that make it difficult to study for genes location and identification. Improving productivity, fruit quality and resistance to biotic and abiotic stresses is the main objective of molecular analyzes in date palm. In this paper, we examine the considerable progress in this area. Progress in date palm genomics studies was reviewed to provide a useful reference for researchers working in this area. Advances in molecular techniques will facilitate improvement programs using molecular selection.
8 Study of the biotic potential of the parasitoid Encarsia sophia under controlled conditions , Ben Belgacem Ali and Belkhadi Mohamed Sadok
Bemisia tabaci Gennedius (1889) is a phytophagous pest affecting various crops all over the world. Biological control against B. tabaci is based on the use of its natural enemies, especially parasitoids and predators. In this context, several parasitoid species of the genus Eretmocerus and Encarcia and predators (such as Nesidiocoris tenuis) whose effectiveness has been proven, are used in the control of this white fly. The evaluation of the potentialities of the indigenous parasitoid Encarsia sophia has shown a performance in limiting the populations of B. tabaci in geothermal greenhouses in southern Tunisia. However at 25 ° C and relative humidity varying between 55 and 75%, the parasitism rate of E. sophia of B. tabaci larvae L2, L3 and L4 on eggplant culture is 14.72 ± 5.60%. It is concluded that the use of this native enemy of B. tabaci can remedy the multiplication of this pest.
9 Oligonychus afrasiaticus (Mcgregor): Problem of date palm infection and its management: A review , Bennour Chaker, Ben Belgacem Ali, Hamza Hammadi and Ben Nasr Hmed.
Oligonychus afrasiaticus is one of the most destructive mites of the date palm. It is very widespread in the world. Various strategies are used in its control. However, any procedure seems able to elminate it successfully. We describe, in this paper, the biology of the species, chemical and biological methods used in its control and we end up raising some problems in relation with the cause of its emergence and the refuges which shelter this mite during all the months of the year.
10 Comparison of the effectiveness of the most used chemicals against Tuta absoluta in Tunisia ,  Ettaib Refki, Aoun Faouzi, Assadi Besma, Ben Belgacem Ali , Chouikhi Sabrine, Bazmi Ali and BelKadhi Mohamed Sadok
Control failures with several chemicals have prompted research into the resistance status of Tuta absoluta and the effectiveness of certain active ingredients against this pest. In this context, a comparison was made of the effectiveness of the most widely used chemicals against T. absoluta in Tunisia. The results show that the L1 larval stage of Tuta absoluta is very sensitive to all of the chemicals tested. Stage L2 is sensitive to Spinosad, indoxacarb and emactin, while Bacillus thuringiensis, martine do not cause 50% mortality. L3 stage mortality fluctuates between 20% and 80% mortality. The L4 stage is more affected by the treatment with Bacillus thuringiensis which can go to 100%. Based on these results, chemical treatments should be directed according to the dominant larval stage in the plants.
11 Effects of Raméal Fragmented Wood (RFW) amendments on the physico‐ chemical characteristics of the oasis soil in Southern Tunisia , Latifa Dhaouidi, Nissaf Karbout, Bouthaina Zoughari
Increasing attention is being paid by farmers and extension services to soil amendment with small branches, especially as ramial fragment wood (RFW). This article presents the results concerning the effect of buried inputs of RFW on the soil oasis of Tozeur region in two different sites : El Manachie oasis of CRAAO oasis. The amendement with RFW has a positive effect on the physicohydric properties of the soil (humidity, porosity structure), enhance the soil organic matter concentration, stimulates biological activity, and increases the availability of nutrients. The effects of RFW are modulated by several factors, such as dose, periodicity, size of fragments, etc.). But in the long term RFW can cause adverse effects on soil salinity if be used in an uncontrolled doses.
12 Comparative Ethnobotanical Study of Medicinal Plants of a Mountainous Region "Djebel Djedoug" and an Oasis Environment "Oasis of Boussaâda" in the North of M’sila (Algeria) and Therapeutic Uses. [In French] , Authors: Benderradji Laid, Bounar Rabah, Ghadbane Mouloud & Rebbas Khellaf
This work aims to determine the traditional uses of medicinal plants in the site of Djebel Djedoug located at the north of M’sila region (Algeria). This locate contains a rich and diversified medicinal flora. The ethnobotanical surveys carried out using the questionnaire cards made it possible to inventory 64 medicinal species belonging to 35 botanical families, and to collect as much information as possible about the traditional therapeutic uses of the local population. In addition, the results can be considered as a source of information for scientific research in the field of phytochemistry and pharmacology.
13 Improving Quality of Arabic Dates by low Doses of Irradiation. , Serag Farag, AzzaEl-Dawlae, Hesham Swallem & Gado Ahmed
This work  aim to select the optimum dose of γ-rays for  keeping  quality of semi dry  dates(SDD) through studying physical, chemical ,microbiological characters besides disinfestations of dates. Three Arabic SDD varieties as Siwi (Egypt), Sukkary (Saudi Arabia) and Zahidi (Iraq) at ‘Tamar’ stage were  irradiated with γ-rays (0.0,1.0, 3.0  5.0 kGy).The storage of  packaged treated samples was extended eight months at room temperature (20 ~25 C°, 70~75%RH). The free radicals was monitored by Electron Spin Resonance (ESR), survey insects and microbes. Besides, tracking the changes of bioactive content (amino acid- AA, sugars and Soluble Solid Contents -SSC). Results revealed that ESR-signals of   edible parts were completely disappeared after one month whereas it’s present in kernels. Also, irradiation eliminated completely all stages of insects and reduced the microbial load either fungi or bacteria. HPLC- analysis of AA showed presence of seventeen one (µg/g dry weight), in all tested samples, the difference occurred due to variety and irradiation dose. Sugars were accumulated at end of   storage (8 months), whereas negligible changes were recorded in total, reducing or non-reducing sugars but were significantly between varieties. Same trends were noticed in SSC. At the end, the preferability  of using low dose  of γ–irradiation are suitable on large scale, safe alternative for using pesticides and sufficient for  keeping quality of tested  Arabic  semi dry dates without high losses in nutritive values.
14 Study of the physico-chemical and functional properties of carob syrup. [In French] , Leila Tounsi, Héla Kechaou & Nabil Kechaou
The carob tree has several advantages for all its components, especially for its fruits (carob pods). Several scientific studies have shown that the carob fruit is rich in nutrients and phytochemicals, which explains its use as a raw material for the manufacturing of various products, including carob syrup. Some studies have been carried out on the physicochemical characteristics of this product, but to our knowledge, there are no scientific studies yet regarding its functional properties and its potential use in the food industry. So, this work clearly shows that carob syrup has interesting functional properties. It exhibits an emulsifying capacity (~ 80-87%) comparable to that of soy lecithin (~ 100%), an emulsifier widely used in food formulations. This result reveals that carob syrup can be used as a natural food emulsifier for the formation and stability of emulsions.
15 Study of some growth and biochemical parameters of the olive tree (Olea europaea L.) fertilized with sewage sludge. , Mohamed Zouari, Samir Aydi, Ferjani Ben Abdallah, Chedlia Ben Ahmed, Nacim Zouari & Bechir Ben Rouina
The present study shows an interesting effect of soil enrichment with 5% sewage sludge on the behavior of young olive trees. In fact, a significant improvement in the length of the main stem is observed. By providing nutrients, the sewage sludge (5%) also increased the leaf nitrogen content. However, doses of 10 and 15% increase stress indicators in terms of malondialdehyde content and loss of electrolytes, which could be explained by the important level of salts and organic pollutants in sewage sludge.
16 A review of the management of Aphis fabae Scopoli (Hemiptera: Aphididae). , Bennour Chaker, Ben Belgacem Ali & Ben Nasr Hmed
The black-bean aphid Aphis fabae Scopoli is a serious agricultural threat spreaded almost worldwide. It threatens more than 200 host plant species and causes several damages through sucking sap, injuring leaves, the excretion of honeydew -inducing the development of sooty mould- and the transmission of plant viruses. Chemical aphicides are the most approach used to control A. fabae. Nevertheless, their extensive use has led to serious problems concerning human health and environment. These drawbacks led to apply eco-friendly strategies based on entomopahtogenic fungi, natural enemies and plants to manage the pest. In this paper, we review the biological control of A. fabae with special reference to management using plant extracts. Many plants belonging to several families are opted to control A. fabae. Several parts of these plants in particular leaves, stems and peels are used to eradicate it. Aqueous and alcoholic extracts are the most used forms. The mode of action of the major compounds of botanicals is through stomach or/and nerve poisoning.
17 Suitability of Ectomyelois ceratoniae Zeller (Lepidoptera: Pyralidae) as host for two local Trichogramma species (Hymenoptera: Trichogrammatidae) and possible implications on biological control programs. , Zouba Anis, Abbes Khaled, Zougari Sahar, Ben Hmida Foued & Chermiti Brahim
In this study, laboratory tests were conducted to evaluate the suitability of Ectomyelois ceratoniae (Zeller) eggs as host for the development of two Trichogramma species: Trichogramma cacoeciae (Marchal) and Trichogramma bourarachae (Pintureau and Babault) (Hymenoptera: Trichogrammatidae) collected in Tunisia and reared on Ephestia kuehniella Zeller eggs. We also studied effects of five different temperature regimes (15, 20, 25, 30 and 35°C) on the biological traits of these two parasitoids. Results showed that eggs of E. ceratoniae were more suitable for the development of T. bourarachae. The number of parasitized eggs (15.46±2.04) as well as the emergence rate (95.78±5.10) was significantly higher compared to T. cacoeciae. For both Trichogramma species, the highest parasitism rate was observed at 30°C. At 35°C, the mean number of parasitized eggs (32.06±13.32) and the longevity (4.03±0.56) of T. bourarachae females were significantly higher compared to T. cacoeciae. The developmental time of both Trichogramma species was shorter at higher temperatures. The emergence rates were similar and relatively high in all tested temperature ranging from 80.48% to 97.92% for T. bourarachae and from 92.03% to 99.33% for T. cacoeciae.
18 Antioxidant responses are associated with differences in drought tolerance between maize and sorghum. , Ali Ali Elnaeim Elbasheir & Ludidi Ndiko
Drought is a major cause of decreased yield in crops worldwide. Sorghum (Sorghum bicolor) and maize (Zea mays) are two of the key crops in Africa serving as human food as well as livestock feed. For improved crop production, selection for drought resilient genotypes is imperative and the biological basis for drought tolerance ought to be fully understood to achieve such selection. Sorghum can tolerate drought better than maize and it is a key model for studying the physiological and biochemical mechanisms conferring drought tolerance. In this study, comparative analyses in terms of changes in growth, chlorophyll content, ROS content, lipid peroxidation level and the activity of antioxidant enzymes were investigated. Exposure to drought triggered ROS generation in both plant species. However, sorghum showed less cell damage under water deficit compared to maize. Furthermore, differences in antioxidant enzyme activity between maize and sorghum were identified. Our findings reveal differences in and association between the physiological and biochemical responses of maize and sorghum to drought, which may be relevant for breeding drought tolerant crops.
19  Effects of salt stress on the germination of two contrasting Medicago sativa varieties. , Jabri Cheima, Zaidi Nawres, Maiza Nourhene, Rafik Khawla, Ludidi Ndiko & Badri Mounawer
Selection strategies for increased salt tolerance in Medicago sativa must involve several growth stages, with the germination stage as a particularly important stage. At this stage, M. sativa is known to be more sensitive to salt than later growth stages. Cultivars differ significantly in their capacity to germinate under saline conditions. For this consideration and in order to analyze the response to salinity, initial screening at the germination stage for two varieties of M. sativa was undertaken. Seeds were germinated in Petri dishes under control treatment (0 mM NaCl) and four concentrations of NaCl (100, 150, 200 and 250 mM). Results from ANOVA showed that variation in root length (RL), fresh root weight (RFW) and shoot fresh weight (SFW) was explained by variety effect. The variation in hypocotyl length, (HL) SFW and RL was explained by the interaction of variety x treatment. Under salt stress, there was a major reduction (46, 66%) in final germination rate (GR) when seeds were geminated in 250 mM NaCl. The RL and HL were affected by salt stress and their respective values were reduced by more than 40% in 200 mM NaCl. The Californian variety was lesser affected by salt stress for RL and RFW while the local variety from El Hemma showed the lowest reduction for SFW. Further work is needed to asses these effects in later growth stages and in field conditions under salt stress.
20 Comparative analysis of responses to field salinity stress in contrasting soybean accessions highlights NaCl exclusion in leaves as a key mechanism for salinity stress tolerance. , Akanbi Musa Oyebowale, Egbichi Ifeanyi Moses & Ludidi Ndiko
Salinity is one of the main limitations to legume productivity in many regions of the world and it is estimated that 50% of all arable land will become affected by salinity by 2050. The impact of field salinity on soybean performance was assessed using two soybean accessions (KCW and HMC) cultivated in salt-treated soil and non-salt treated soil. We used a 30 cm deep field system layered with 0.4 kg/m2 NaCl for the salt-treated experiment while the control field received no salt treatment. The results show that salinity reduces soybean growth and yield as evident from the reduction in the plant shoot length, stem diameter, number of branches, number of pods and seed weight. However, the reduction in these growth parameters was less pronounced in the HMC accession than the KCW accession. Furthermore, Na+ content in leaves of the HMC accession was lower than that of the KCW accession. This proved that salinity has a damaging effect on soybean growth and yield and the relative tolerance of the HMC accession is attributed in part to its ability to restrict Na+ transport to the leaves. While the study emphasizes salt exclusion as a potentially useful mechanism for salinity tolerance in soybean, it provides evidence that the HMC accession is a good genetic resource for breeding soybean varieties with improved salinity stress tolerance.
21 Analysis of salinity tolerance in two varieties of Medicago sativa at the vegetative stage. , Badri Mounawer, Rafik Khawla, Jabri Cheima & Ludidi Ndiko.
In this study, we analyzed salt tolerance in two varieties of Medicago sativa at the vegetative stage. Gabès2355 and Californian varieties of M. sativa were cultivated under control treatment and under a range of salt concentrations (50 mM, 100 mM, 150 mM, and 200 mM NaCl) in a greenhouse. At harvest, ten quantitative characters related to aerial and root growth were measured for plants of both varieties. Results from ANOVA showed that the variation of the traits measured is explained by the effects of variety, treatment and the interaction of variety x treatment. The treatment factor represents the most pronounced effect. While the Californian variety was more sensitive than the Gabès variety under 50 mM NaCl, it was the most tolerant under higher concentrations of NaCl. Specific correlations between measured traits were noted under control treatment and salt stress. Further work is needed to evaluate the agronomic performances of both varieties in the field under salinity constraint.
22 Effects of osmotic stress on Chenopodium quinoa seed germination. , Derbali Imed, Manaa Arafet, Derbali Walid & Slama Inès
Quinoa is a pseudo-cereal native to the Andes known for its exceptional adaptation to extreme soil and climate conditions. The study of the response of Chenopodium quinoa to osmotic stress and the contribution to improving its yield aims to ensure production in arid and semi-arid regions as an alternative crop. The aim of this study is to test the germination capacity of 5 selected varieties; CQ-57, UDEC-2; ICBA-4, ICBA-5 and 115-R subjected to varying osmotic pressures using solutions of PEG-6000 and NaCl. Seeds are incubated at 25 °C for 10 days. Results showed that osmotic stress increases the lag phase but does not affect the germination rate at low concentrations of PEG and NaCl. While for high concentrations the germination rates decrease as compared to controls. Radicale and hypocotyl lengths decreased with increasing the degree of osmotic stress. The effects of osmotic stress are comparable in the 5 varieties. At high concentration of PEG or NaCl, ICBA-5 and CQ-57 exhibited the highest value of germination rate showing the capacity of these varieties to establish itself in regions suffering from salinity or water deficit.
23 Indigenous African cereal crops can contribute to mitigation of the impact of climate change on food security. , Basson Gerhard, Ali Ali Elnaeim Elbasheir & Ludidi Ndiko
Zea mays L. (maize) is one of the top three cultivated cereals globally, along with wheat and rice. The United States, China, and Brazil are among the largest producers of maize, producing approximately 79% of the world’s maize. Maize is used to produce human food and animal feed. It is also used to produce industrial products such as starch sweeteners, oil, beverages and bioethanol. South Africa produces maize as well. However, this production is relatively insignificant compared to the major producers. Furthermore, South Africa is a semi-arid country and as such receives less rainfall and has annual droughts. This has negative implications on maize production, which threatens food security. The sole reliance on a limited number of staple cereals is not a sustainable option. In order to truly improve food security, the diversification of staple cereals is necessary. Therefore, this review aims at discussing the diversification of staple cereals in southern Africa, specifically focusing on sorghum, pearl millet, finger millet and teff. These African indigenous cereals are known for their environmental resilience as well as having nutritional benefits. Southern Africa will experience more droughts in the future as a result of climate change, which will undoubtedly impact maize yields. Therefore, it is important that efforts are intensified to ensure that indigenous drought-adapted crops are fully exploited to improve future food security.
24 Effect of phosphorus deficiency induced in calcareous soil on plant growth, phosphorus use efficiency and acid phosphatase activity of Medicago truncatula. , Kouas Saber, Slatni Tarek, Mhadhbi Haythem & Abdelly Chedly
Calcareous soils, characterized by a higher pH, are frequent in the North West of Tunisia. Large concentrations of calcium carbonate in calcareous soils result in accumulation of high levels of bicarbonate ions, which complex with phosphate, resulting in phosphorus deficiency (induced P deficiency) for plants. The impact of calcareous soil on plant growth, photosynthetic activity and acid phosphatase activity was explored in two lines of Medicago truncatula: TN6.18 and Jemalong. Calcareous soil significantly restricted shoot growth only in Jemalong (-45 % of the control). When grown on calcareous soil, root length was stimulated, this effect being more pronounced in TN6.18. Under calcareous soil, net CO2 assimilation declined more in Jemalong (-40 % of the control) than in TN6.18 (-20 % of the control). CO2 accumulation was increased in Jemalong (+35% of the control) plants grown in calcareous soil. The acid phosphatase activity was higher in plants cultivated under calcareous soil. This increased phosphatase activity was more pronounced in TN6.18, which showed higher accumulation of Pi in shoots and roots than Jemalolng.  In the light of these results, the present study proposes acid phosphatase as a useful candidate for improving Pi acquisition and utilization under calcareous soil.
25 High diversity of responses among Medicago truncatula lines to Phoma medicaginis infection. , Maiza Nourhene, Jabri Cheima, Zaidi Nawres, Rafik Khawla, Khiari Bilel, Djébali Naceur, Sánchez-Ballesta Maria Teresa & Badri Mounawer
Medicago truncatula is an omni-Mediterranean species grown as an annual forage legume. In addition to its small genome size and simple genetics, M. truncatula harbors several attributes, which make it an attractive model forage plant. In this study, we investigated the variation of responses in ten parental lines of M. truncatula to Phoma medicaginis infection. Plants were cultivated in the growth chamber under controlled conditions and were inoculated after two months with P. medicaginis. At harvest, 13 quantitative traits of growth and pathogenicity were measured. Results from ANOVA showed that the variation of analyzed parameters was explained by the effect of line. All measured parameters, except the root fresh weight, showed significant difference among the 10 studied lines. Most tolerant lines are those with the lowest ratios of the number of infected and dead leaves. Studied lines were clustered into three groups according to their responses to P. medicaginis infection. The most resistant TN6.18 line and most sensitive F83005.5 to P. medicaginis are useful for the exploration of physiological mechanisms and genetic determinants for M. truncatula tolerance to this constraint.
26 Variation of Medicago sativa varieties tolerance to Phoma medicaginis infection. , Zaidi Nawres, Jabri Cheima, Maiza Nourhene, Rafik Khawla, Khiari Bilel, Djébali Naceur, Ludidi Ndiko & Badri Mounawer
Due to its very important agronomic value and nutritional quality, Medicago sativa L. is considered as the queen of fodder and the first cultivated forage crop in the world. In field conditions, M. sativa is exposed to several biotic and/or abiotic constraints that affect its quality. In this regard, research is still underway to improve M. sativa resistance to many biotic stresses and, in this context, we analyzed the responses of a core collection of 10 varieties of M. sativa to Phoma medicaginis infection. Results from ANOVA showed that most growth parameters exhibited significant differences between the studied varieties. Nevertheless, only the number of healthy leaves among infection parameters varied significantly between the varieties. The local variety Gabès2355 exhibited the highest biomass. Positive correlations were found between the measured parameters. PCA based on the traits showing significant differences among the studied lines showed that the Gabès variety formed a separate group. Cluster analysis revealed that the studied varieties are classified into three major groups. The first group is formed by Gabès2353, the second group is composed of the Californian and El Hamma varieties, and the third group is constituted of the seven remaining varieties. Gabès2355 was the most tolerant to the Pm8 strain of P. medicaginis while Magna601 variety was the most susceptible. These two varieties will be useful to analyze the physiological and genetic determinants for M. sativa tolerance to P. medicaginis infection.
27 Comparative study of Pyrenophora graminea incidence on Hordeum vulgare L. hybrid populations and their parents. , Afissa Wahiba & Siaki  Fadhila
The seed- borne pathogen Pyrenophora graminea Ito& Kur. is the causal agent of barley leaf stripe, a destructive disease in most barley growing region in the world. In order to  improve the barley species in Algeria against this disease, it is necessary to know their tolerance reaction  to it. The genotype that have been tested are five parent genotypes: ACSAD,  Tichedrett,  Saida,  Rihane,  Hamra and eight populations hybrid obtained by intraspecific crosses of the parents and then sowing of F1 to F8. We compared the incidence of the isolate of Pyrenophora graminea  for morphological characters (Stem height) and yield (1000-grain weight, medium yield of plant) of the studied variety. The results obtained showed the existence of variability between our thirteen genotypes of barley which had a different resistance level in the quantitative and qualitative characters.
28 Environmental variation and geographic distribution of the Brachypodium distachyon grass complex species’ in Tunisia. , Gandour Mhemmed
The Brachypodium genus contains the model grasses B. distachyon, B. stacei and B. hybridum, that are useful for molecular and physiological studies relevant to grain, pasture and bioenergy crops, as well as ecology. In this paper, we analyze the natural variation in climate/geographical diversity that exists within these species in the Tunisian territory. To capture the genetic diversity within this species complex in relation to their geographic distribution in Tunisia, 360 of Brachypodium accessions from the Tunisian territory were collected and genotyped by ALB165 marker. Overall, 314 samples were classified into hybridum and the rest as diploid for one of the two progenitor’s species (B. distachyon and B. stacei). Environmental niche analysis indicated that, generally, B. distachyon grows in higher, cooler, and wetter places north of 36°; B. stacei in lower, warmer, and drier places; nd B. hybridum in places with intermediate ecological features and across latitudinal boundaries but also overlapping with those of its parents, more often with those of B. stacei.
29 Characterization of Pisum sativum Mediterranean accessions by qualitative traits. , Jlassi Ines, Jandoubi Wassim, Mansouri Dhouha, Boukhibar Halima, Soraya Touzout Naila, Ben-Attia Mossadok & El-Bok Safia
Nowadays, pea field is getting more attention because of its nutritional values.  The objective of this paper is to characterize and identify relationships among 21 Mediterranean pea accessions.  Fifteen accessions of Pisum sativum subsp. elatius and six accessions of Pisum sativum subsp. arvense were provided by ICARDA (International Centre for Agricultural Research in Dry Areas). Twenty qualitative traits were selected according to the guidelines of the International Union for the Protection of New Varieties of Plants (UPOV). We measured eight vegetative qualitative traits such as presence or absence of leaflets, type of plant axis development and presence or absence of anthocyanin coloration. We measured twelve floral qualitative traits such as standard color, pod color and curvature of the pod. In order to study the clustering of our accessions, we used Past4.03 with the test UPGMA (unweighted pair group method with arithmetic mean). The biometric and descriptive analysis we carried out reveals the presence of traits that discriminate accessions. Among these traits, we can cite C15 (vegetative qualitative trait), C23, C31 and C35 (floral qualitative traits). C15 discriminates the accessions TUR10, TUR8, SYR1 and SYR2. C23 distinguishes TUR6, TUR11 and AL2 accessions from other accessions. C31 is a discriminating trait for TUR13 accession. The type of starch grain (C35) discriminates the TUR14 accession. Cluster analysis led to establishing dendrogram allowing a grouping of accessions according to their geographical affiliation. In fact, it is possible to discriminate significantly the accessions TUR10, SYR1 and SYR2 from the accessions TUR12, TUR13, GR1 and TUN which could be an incentive for further improvement and better exploitation.