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Khaldi Z.,Center Regional Of Recherches En Agriculture Oasienne | Rekik B.,Ecole Superieure dAgriculture | Haddad B.,Institute National Agronomique Of Tunisie | Zourgui L.,Gafsa University | Souid S.,Gafsa University
Livestock Research for Rural Development | Year: 2010

Genetic structure and diversity were investigated by random amplified polymorphic DNA (RAPD) markers in three Tunisian sheep breeds. These breeds were: Barbarine, Queue Fine de l'Ouest and D'man. The DNA samples were isolated from 160 animals from the three breeds. Twenty random primers were used for this study. Only 9 primers produced clearly polymorphic and reproducible bands. Level of polymorphism varied from 71.42 to 88.88 per primer and from 75.43 to 83.02 per breed. Genetic variation in studied breeds was measured with three indices (Nei's gene diversity, Shannon's information and level of polymorphic loci) and showed that the highest diversity was found in the exotic D'man breed while the lowest diversity was obtained for both the Barbarine and Queue Fine de l'Ouest native breeds. The inter breed similarity indices and the UPGMA dendrogram, based on genetic distance clearly separated the three breeds. The closest relationship was observed between Tunisian Barbarine and Queue Fine de l'Ouest breeds. The AMOVA analysis indicated that the largest part of the genetic variability (97.86%) originated from differences among individuals within breeds. Source

Annicchiarico P.,Italian Agricultural Research Council | Pecetti L.,Italian Agricultural Research Council | Abdelguerfi A.,Montpellier SupAgro | Bouizgaren A.,French National Institute for Agricultural Research | And 4 more authors.
Field Crops Research | Year: 2011

Lucerne (Medicago sativa L.) can enhance the economic and environmental sustainability of crop-livestock systems in the western Mediterranean basin, but requires improved adaptation to stressful environments because of a predicted shortage of irrigation water and climate change. This study reports on three-year dry matter yields of five landraces from Morocco, Italy and Tunisia and seven varieties from France, Italy, Australia and USA assessed across 10 agricultural environments of Algeria, Tunisia, Morocco and Italy of which four were rainfed, one was continuously irrigated (oasis management), and five were irrigated but adopted a nine-week suspension of irrigation during summer. Our objectives were targeting cultivars to specific environments, and assisting regional breeding programmes in defining adaptation strategies, genetic resources and opportunities for international co-operation. The crop persisted well in all environments, but environment mean yield was strictly associated (P<0.01) with annual and spring-summer (April-September) water available. Rainfed cropping implied 42% lower yield with 61% less spring-summer water available relative to irrigation with withheld summer water across three sites hosting both managements. All of these sites showed genotype×management interaction (at least P<0.10). Cross-over genotype×environment (GE) interaction between top-yielding cultivars occurred across the 10 environments. Total number of harvests (range: 9-23), soil salinity as measured by electrical conductivity (range: 0.20-6.0dSm-1), and average spring-summer water available (range: 102-932mm) were selected as significant (P<0.05) environmental covariates in a factorial regression model explaining 53% of GE interaction variation. This model was exploited for targeting cultivars as a function of site-specific levels of these factors. Its indications agreed largely with those of an additive main effects and multiplicative interaction model with two GE interaction principal components. An Italian landrace exhibited specific adaptation to severely drought-prone environments, whereas landraces from north Africa were not adapted to such environments. One Moroccan landrace was specifically adapted to high number of harvests (partly reflecting frequent mowing). One variety selected for salt tolerance, and one Moroccan landrace, were specifically adapted to salt-stress environments. Environment classification as a function of GE interaction effects indicated three groups which may be object of specific breeding: (i) rainfed or irrigated environments featuring limited spring-summer water available (<350mm), nil or low soil salinity, and moderate to low number of harvests; (ii) salt-stress environments; and (iii) environments characterized by high number of harvests. © 2010 Elsevier B.V. Source

Blanchet F.,Ecole Superieure dAgriculture | Valdebenito-Sanhueza R.M.,Proterra | Spolti P.,Federal University of Rio Grande do Sul
Tropical Plant Pathology | Year: 2012

Among the practices recommended for apple scab (Venturia inaequalis) control, the use of genetically resistant cultivars is of great importance in integrated management programs, in which restrictions to fungicide use are common. In this study we used multivariate analysis techniques to identify variables useful in apple breeding programs for detecting partial resistance to V. inaequalis and to rank cultivars for this resistance type. A collection of ten old apple cultivars from propagative material 35 to 50 years old was evaluated for partial resistance to the pathogen. CNPUV-09 and CNPUV-04 had levels of resistance similar to that of cultivar Prima, the standard resistant cultivar. The stroma and apressorium (ST + AP) formation and sporulation (ESP) of the pathogen after a foliar inoculation by conidial suspension were the largest eigenvectors of the first and second principal components, and contributed with 23.9% and 28.5% of the total variance, respectively. ST + AP and ESP were highly correlated with first and second axes. These variables could be useful in apple breeding programs to select cultivars with partial resistance to V. inaequalis. Source

Ghazghazi H.,Institute National Dagronomie Of Tunis | Miguel M.G.,University of Algarve | Miguel M.G.,University of Lisbon | Hasnaoui B.,Institute Sylvo Pastoral | And 5 more authors.
African Journal of Biotechnology | Year: 2010

The antioxidant activity of leaf extracts of Rosa canina from diverse localities of Tunisia were evaluated by ABTS and DPPH methods, whereas in those of essential oils and carotenoids extracts such activity was determined only by the ABTS method. Total phenols determined by the Folin method revealed that at Aindraham, samples showed a great variability of phenol content in contrast to those from Feija. After chemical analysis of the essential oils by gas chromatography (GC) and gas chromatography coupled to mass spectra (GC-MS), revealed that the oils of Feija were predominantly composed of palmitic acid, vitispirane, linoleic acid, lauric acid, myristic acid and phytol acetate, while in those samples from Aindraham predominated vitispirane, palmitic acid, linoleic acid and phytol acetate. Higher concentrations of β-carotene and lycopene were found in the samples from Aindraham after determination by high performance liquid chromatography (HPLC). All samples possess antioxidant activity, nevertheless much more significant in phenol extracts in contrast to the carotenoid extracts, which possess the lowest activity. © 2010 Academic Journals. Source

Rjiba Ktita S.,French National Institute for Agricultural Research | Chermiti A.,French National Institute for Agricultural Research | Mahouachi M.,Ecole Superieure dAgriculture
Livestock Research for Rural Development | Year: 2014

This study aimed to introduce marine plants into concentrate mixtures in order to produce rabbit meat. Two species, Ruppia maritima and Chaetomorpha linumwere incorporated in concentrate formula (14 and 27%), with barley, wheat bran, straw and soybean meal, the mixtures (R14, R27, C14, C27) were pelleted with specific laboratory instrument and given ad libitum to 30 New-Zealand rabbits divided into 5 equal groups. Commercial pellets were used as control. Feed intake, growth rate and slaughter performances of rabbits were determined by measuring daily refusals, weekly animal weights and carcass quality after slaughtering.The two marine species studied were very rich on minerals mainly on trace elements as Iron and Manganese. Crude protein and crude fibre contents of control and experimental pellets averaged respectively 19 and 13.5% DM. In the contrast, ash values of the marine plant concentrates were higher than that of the control one. Young rabbits averaged 1264 g of weight at the beginning of the experience and the effect of the diet on the final weights was highly significant. Rabbits fed the experimental diets had lower daily feed intakes than those fed the control one. However, average daily gains were similar between the control and R14 groups but significantly higher than those of C14 and C27. Feed conversion ratio varied from 2.05 with R15 diet to 3.42 with the control one, the difference among all the groups was not significant. Hot carcass weights were highly affected by the diets, the values varied respectively from 1519 g with the control group to 815 with C14. The carcass yield averaged 48.75% between control, R14, R27 and C14 diet, this yield was significantly higher than that released by the animals eating C27 pellets. The species Ruppia maritima gave the best performances, even at an incorporation rate of 27 % into the diet. A particular attention must be taken to the mineral composition of the mixtures mainly those based on the species Chaetomorpha which showed negative results with an incorporation rate of 27% into the diet. © 2014, Fundacion CIPAV. All rights reserved. Source

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