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Barbour EK Itani HH Sleiman FT Saade MF Harakeh S Nour AM Shaib HA 《Tropical animal health and production》2012,44(1):87-93
Three objectives were included in this research work. The first objective compared different immune components in healthy
mature males, mature females, and female kids of local and imported Saanen goats, reared under a sub-tropical environment.
The significantly differing immune components were the blood monocyte percent, blood CD8 count, and the total white blood
cell count. The second objective compared the performance of Saanen versus local does. The means of the milk yield and prolificacy
of the imported Saanen does were significantly higher than those of the local does (p < 0.05). The third objective compared the immune responses (hemagglutination-HA titers) and complement fixation (CF) titers
in mature does of the two breeds to chicken red blood cells (c-RBC). The HA titers showed a significant seroconversion only
in imported Saanen (p < 0.05) but not in local does; however, the CF titers increased significantly at 4 weeks following priming with c-RBC in
local (p < 0.05) but not in the imported Saanen does. The impact of the differences in blood immune components and responses to antigens
in the compared goats on protection potential against prevalent diseases in the sub-tropical zone of the eastern Mediterranean
countries is discussed. 相似文献
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Makrem Afif Chokri Messaoud Abdennacer Boulila Hnia Chograni Afef Bejaoui Mohamed Nejib Rejeb Mohamed Boussaid 《Annals of Forest Science》2008,65(7):710-710
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Pedro Álvarez-Álvarez Elías Afif Khouri Asunción Cámara-Obregón Fernando Castedo-Dorado Marcos Barrio-Anta 《Annals of Forest Science》2011,68(3):497-509
• Background
The effects of foliar nutrients and environmental variables on site productivity in Maritime pine (Pinus pinaster Ait.) stands in Asturias (NW Spain) were studied. 相似文献5.
Chokri Messaoud Makrem Afif Abdennacer Boulila Mohamed Nejib Rejeb Mohamed Boussaid 《Annals of Forest Science》2007,64(8):845-853
The genetic variation of six Tunisian Myrtus communis L. (Myrtaceae) populations was assessed using nine isozymes coding for 17 putative loci and 79 RAPD markers, amplified by five decamer random primers. The analysed populations belonged to three bioclimatic zones (lower humid, sub-humid and upper semi-arid). A high genetic diversity within populations was detected both by isozymes and RAPDs. The level of variation differed according to bioclimate. Populations collected from sub-humid bioclimate showed more polymorphism than those grown in the upper semi-arid zone. For all populations, the genetic diversity revealed by RAPDs was more pronounced than that detected with isozymes. A high differentiation among populations related to bioclimate and geographic distance was revealed by both methods. Population’s structure based on RAPD markers was more concordant with bioclimatic zones in comparison with isozymes. Differentiation between ecological groups was higher than that revealed within groups. Conservation programs should take into account the level of genetic diversity within population revealed by the two complementary classes of markers according to bioclimate. 相似文献
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Afif Makrem Ben Fadhel Najeh Khoudja Mohamed Laarbi Boussaïd Mohamed 《Genetic Resources and Crop Evolution》2006,53(7):1501-1511
The last two centuries witnessed the human-caused fragmentation of Tunisian Ceratonia siliqua L. (Caesalpinoideae) populations which were often represented by scattered individuals. Seventeen populations growing in
four bioclimatic zones: sub-humid, upper semi-arid, mean semi-arid and lower semi-arid zones, were sampled for allozyme diversity
to assess their genetic diversity and structuration using eight isozymes revealed by starch gel electrophoresis. The species
showed high diversity within populations. The average number of alleles per polymorphic locus was 1.98, the percentage of
polymorphic loci was 83.4% and the mean observed heterozygosity (Ho) and expected heterozygosity (He) under Hardy–Weinberg
equilibrium were respectively 0.247 and 0.316. A substantial level of inbreeding within populations induced by Wahlund effect,
was observed (FIS = 0.231). High diversity resulted from the great number of genotypes in the ancestral population before fragmentation, favoured
by the outbreeding of the species. High differentiation and low gene flow were detected among populations (FST = 0.200) and among pairs of ecological zones (0.113< FST <0.198). However, the differentiation coefficient of the four zones was low (FST = 0.085) and similar to the average FST for forest trees. Population structuration depends on geographic distance between sites rather than bioclimate, indicating
that structuration has occurred slowly and that climatic conditions have had little effect. Nei's genetic distances (D) between populations were low and ranged from 0.004 to 0.201. Mean D value for all population was 0.087. The UPGMA clustering established for all populations through Nei's genetic distances
did not clearly show that, for the majority of populations, grouping had resulted from ecological factors or geographic location.
The substantial differentiation and the high genetic similarities between populations indicate that populations have been
recently isolated as a result of anthropic pressure. In-situ conservation strategies must first focus on populations with a high level of genetic diversity and rare alleles. Appropriate
conservation action should take account of bioclimatic zones. Ex-situ preservation should be based on a maximum number of individuals collected within populations in each ecological group and
their propagation in different bioclimates by means of cuttings. 相似文献
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Yves Jolivet Matthieu Bagard Mireille Cabané Marie-Noëlle Vaultier Anthony Gandin Dany Afif Pierre Dizengremel Didier Le Thiec 《Annals of Forest Science》2016,73(4):923-943
Key message
Ozone, one of the major atmospheric pollutants, alters tree growth, mainly by decreasing carbon assimilation and allocation to stems and roots. To date, the mechanisms of O3 impact at the cellular level have been investigated mainly on young trees grown in controlled or semi-controlled conditions. In the context of climate change, it is necessary to introduce a valuable defence parameter in the models that currently predict O3 impact on mature trees and the carbon sequestration capacity of forest ecosystems.Context
Air pollution is an important factor that affects negatively forest ecosystems. Among oxidative air pollutants, ozone is considered as the most toxic in terms of impact on vegetation.Aims
This paper focuses on the negative impacts of ozone on trees in controlled conditions or in their natural environment. The current knowledge of the responses at cell level is presented and ways to improve their use for ozone risk assessment of forest stands are discussed.Methods
Information was collected from original papers or reviews, providing an overview of the research conducted over the last 60 years.Results
The negative effects of ozone on carbon assimilation and tree biomass production were reviewed and discussed, with a focus on effects on cell processes implied in cell defence, including stomatal regulation, detoxification, signalling, and biosynthesis of wood compound.Conclusion
In the context of increasing significance of O3 flux approach, this review intends to shed light into the black box of defence processes, which are playing a crucial part within the effective O3 dose modelling. Today, it is recognized that tropospheric ozone inhibits tree growth and its role on the future carbon sink of the forest ecosystem is discussed along with the combination of other environmental factors like elevated temperature, water, and nitrogen supply, likely to be modified in the context of climate change.8.
Hattab Sabrine Hedheli Afif Banni Mohamed Boussetta Hamadi Herrero Maria 《Scientia Horticulturae》2010
In this work, pea (Pisum sativum) plants exposed to increasing cadmium and copper concentrations were tested for heavy metals accumulation in flowers and for ‘in vivo’ pollen germination. Based on the Cd and Cu accumulation amounts in the flowers, an evaluation of the same metals effects on ‘in vitro’ pollen germination was achieved. Moreover, the effects of both metals on fruits number and weight and on seed set and yield at individual plant level were examined. While cadmium concentrations did not affect ‘in vivo’ pollen germination, only higher copper concentrations rendered a significant reduction. This is in contrast with the clear negative effect on pollen germination in vitro and might be explained by the different dynamic and bioavailability of both metals. A clear effect of Cd and Cu was observed on two important yield components ie, fruit weight and seed set. Although results obtained herein cannot give a clear cut relationship between the effect of Ca and Cu on reproductive development and its consequences on yields, they represent emerging results on the potential consequences of metals contamination on reproductive development in plants. 相似文献
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