Breaking seed dormancy in Cupressus atlantica Gaussen,an endemicand threatened coniferous tree in Morocco

Cupressus atlantica Gaussen （Cupressaceae） is an endemic and endangered coniferous tree geographically restricted to the N＇Fis valley in South-Western Morocco. Like many forest species, C. atlantica exhibits dormancy which delays and reduces germination. To improve seed germination, different pre-treatments were conducted on C. atlantica seeds after storage for different periods （one, two and five years） including： scarification with sandy paper; soaking seeds in hot distilled water at 60℃ and 80℃ for 15 min and soaking seeds for 48 h in a gibberellic acid （GA3） at 1,000 and 2,000 mg·L-1. Results showed that scarification with sandy paper increased the germination rate of Atlas cypress by up to 67%, indicating that the species possess essentially an exogenous dormancy （physical dormancy） due to the hard seed coat （hardseededness）. Exogenous application of gibberellic acid （GA3） at 1,000 mg.L-1 was also effective in breaking seed dormancy and germination induction. These two treatments induced faster speed germination expressed by low number of days to first germination （8-10 days） and low values of mean germination times （MGT）. However, germination rate, under any treatment, is greatly dependent on the year of seed collection. Seeds collected in year 2004 gave the highest value, suggesting that even after five years of storage, the germination capacity of C. atlantica seeds could remain high. This observation is very interesting in the ex-situ conservation of such endemic and endangered species where the production of seeds is irregular over the years.

Near-infrared reflectance spectroscopy reveals wide variation in major components of sesame seeds from Africa and Asia

Sesame is an important oilseed crop in Africa and Asia, owing to its high nutritional quality seed and market value. Variation in sesame seed components including oil, oleic acid,linoleic acid, and protein was investigated by near-infrared reflectance spectrometry in 139 samples collected from different countries. Oil and protein contents were between 40.8%and 60.3%(mean 53.0%) and 15.5% to 25.5%(mean 20.4%), respectively. Linoleic acid,ranging from 31.8% to 52.4%(mean 46%) was more abundant than oleic acid(31.8%–50.6%,mean 38.1%). Light-seeded samples displayed higher nutritional quality, as they were richer in oil, protein, and linoleic acid than dark seeds. Samples from Africa had higher oil and linoleic acid contents, while Asian samples had higher oleic content. The analysis revealed West African sesame cultivars containing especially high levels of seed components, which may command high market values. Two clusters of sesame samples grouped by seed composition were obtained, including one cluster with high oil and oleic acid content and the other with high protein and linoleic acid content. This study revealed that sesame samples from Africa and Asia harbor high variation for major seed components and also provided background information for breeding high-nutrition varieties according to the demands of sesame seed markets.

Inoculation with arbuscular mycorrhizal fungi improves seedlings growth of two sahelian date palm cultivars (<i>Phoenix dactylifera</i>L., cv. Nakhla hamra and cv. Tijib) under salinity stresses

This study presents an analysis of the impact of mycorrhizal inoculation on growth under salt stress of date palms cultivars Nakhla hamra (NHH) and Tijib known in the Sahel for their earliness in flowering and fruiting. The seedlings were grown in a greenhouse on a sandy substrate watered to field capacity every two days and were subjected to increasing levels of NaCl (0, 1, 2, 4, 6, 8 and 16 g·L-1) and then inoculated with 5 strains of Glomus (G. aggregatum, G. intraradices, G. verriculosum, G. mosseae, G. fasciculatum). The experimental design was a randomized complete block with three factors (cultivars: Tijib and Nakhla Hamra x seven levels of NaCl concentrations x six levels of inoculum). The results showed that in the absence of NaCl, G. verriculosum significantly enhanced shoot growth: 33.5 cm against 30.3 cm in the control and roots growth: 81.5 cm against 78 cm in NHH, while in Tijib, the growth is stimulated by Glomus fasciculatum: 33.8 cm against 32.7 cm for stems and 90 cm against 86 cm for the roots of inoculated plants and controls. In contrast, in the presence of NaCl 8 g·L-1, NHH has a better growth in the presence of G. intraradices: 37.3 cm against 30.6 cm for stems and 77 cm against 73 for roots, while Tijib grows better in the presence of G. fasciculatum with respectively 31.9 cm against 31.7 cm and 51.27 cm against 51.6 cm for stems and roots of inoculated plants and controls. Biochemical analysis revealed that changes in levels of proline depend on the cultivar, the mycorrhizal strain used and concentrations of NaCl applied. These results open the prospect of using mycorrhizal fungi to improve the productivity of palm trees in the Sahel.

<i>In Vitro</i>Germination and Early Vegetative Growth of Five Tomato (<i>Solanum lycopersicum</i>L.) Varieties under Salt Stress Conditions

In Senegal, tomato (Solanum lycopersicum L.) cultivation is affected by salinity in many agro-ecological zones. The selection of salt tolerant varieties would be an alternative solution to enhance the production. Thus, germination and growth are studied under axenic conditions for five varieties of tomato subjected to increasing concentrations of NaCl [0, 35, 70 and 105 mM], and supplemented in an MS/2 medium for 30 days. The results reveal that salt negatively affects the evaluated parameters. The Rodeo and Lady Nema varieties have the lowest final germination rates (50%) unlike the Mongal variety (55%). These last two varieties have a decrease of 71.78% and 81.28% in the height of the stem, respectively, in the presence of NaCl at [105 mM] while that of the Rodeo variety is 70%. The Xewel variety has the greatest average number of leaves in the presence of [NaCl 35 mM] (4.95 leaves) and [NaCl 70 mM] (4.77 leaves). The Lady Nema variety records the longest taproot length (2.99 cm) unlike the Rodeo variety (2.25 cm) at [NaCl 105 mM]. The Ganila variety reveals the highest number of secondary roots at the concentrations of [0, 35 and 105 mM] of NaCl with, respectively, 44.12, 29.25, and 4.25 roots. The Lady Nema variety records the highest fresh weight of aerial (0.055 g) and root parts (0.014 g) and the lowest root dry weights (0.0023 g). These results allow to conclude that the Lady Nema and Mongal varieties seem more tolerant, Ganila and Xewel are moderately tolerant and Rodeo is more sensitive to the presence of salt.

<i>In Vitro</i>Germination and Early Vegetative Growth of Five Tomato (<i>Solanum lycopersicum</i>L.) Varieties under Water Stress Conditions

Water is the main limiting factor in the cultivation of tomato (Solanum lycopersicum L.) in Senegal. Thus, the selection of varieties tolerant to water stress would be an alternative solution for their production. In vitro germination, growth, total chlorophyll and proline levels were studied in five varieties of tomato subjected to increasing osmotic pressures (0, 5, 10 and 15 kPa) thanks to the PEG-8000 incorporated in an MS/2 medium for 30 days. A strong sensitivity to water stress for in vitro seed germination in the Rodeo variety (41%) is recorded at 5 kPa and maintained at 15 kPa (20.83%) while it was only noticed at 15 kPa in the other tomato varieties. The Xewel and Lady Nema varieties obtained the smallest reductions in the number of leaves of vitroplants, with 30.79% and 27.97% at 15 kPa, respectively, and the Rodeo variety recorded a reduction of 35.97%. From 5 kPa, the varieties record reductions in the number of secondary roots of more than 15%. The effect of osmotic pressures on decreasing the taproot height and length is not significant. The Xewel variety had the highest average fresh (0.483 g) and dry (0.082 g) weights of the aerial part at 15 kPa and the Rodeo variety had the lowest ones (0.308 g and 0.0501 g). The Lady Nema variety had the highest average fresh (0.171 g) and dry (0.039 g) root weights and the Rodeo variety had the lowest ones (0.086 and 0.020 g). The vitroplants of Rodeo variety recorded the highest decreases in total chlorophyll contents at all osmotic pressures and the lowest increase in proline content (53.37%) at 15 kPa. A contrario, the Xewel variety recorded the greatest increase in proline content (116.26%). Ultimately, the vitroplants of Lady Nema and Xewel varieties were more tolerant to water stress, the Ganila and Mongal varieties were moderately tolerant and the Rodeo variety was the most sensitive.

Biodegradation of Toxic Compounds in Olive Mill Wastewater by a Newly Isolated Potent Strain: <i>Aspergillus niger</i>van Tieghem

Thirty-two strains isolated from olive oil production plants were screened for their tolerance to the polyphenols and their ability to grow in olive oil mill wastewaters (OMW). An Ascomycete isolate that grew best on OMW was selected for further study to evaluate its effect on removal of organic pollutants, phenolic compounds and OMW toxicity. This strain was identified by DSMZ as Aspergillus niger van Tieghem. The growth of Aspergillus niger van Tieghem on stored OMW decreased pH and led to the reduction of phenolic compounds with a resultant discoloration of OMW and significant reduction of chemical oxygen demand (COD), in proportion to the dilution of OMW. The reduction of the COD, phenolics and color exceeded 50%. Tannase, the enzyme detected in the growth medium of Aspergillus niger van Tieghem was produced during primary metabolic growth. The maximal enzyme activity attaining 0.68 EU/ml was achieved in 3rd days of cultivation. The phytotoxicity of the stored OMW was reduced to about 40% after 4 days’ incubation with Aspergillus niger van Tieghem.

Development of new cowpea(Vigna unguiculata)mutant genotypes,analysis of their agromorphological variation,genetic diversity and population structure

Cowpea is one of the most important legume grains in the sub-Saharan region of Africa used for human consumption and animal feed,but its production is hampered by biotic and abiotic constraints raising the need to broaden its genetic basis.For this purpose,seeds of two cowpea varieties Melakh and Yacine were irradiated with 300 and 340 Gy of gamma-ray,respectively.The developed mutant populations were agromorphologically characterized from M5 to M7,while the genetic diversity of the latter was evaluated using 13 ISSR markers.Based on the agromorphological characterization,variation of flower color,pod length,seed coat color,and seed weight with 78.01,68.29,94.48,and 57.58%heritability,respectively,were recorded in the mutant lines.PCA analyses allowed to identify the elite mutants based on their agromorphological traits,while Pearson’s correlation results revealed a positive correlation between yield and yield component traits.Three subpopulations were identified through STRUCTURE analyses,but the assignment of the individuals in each group was improved using DAPC(Discriminant Analysis of Principal Components)analysis.Analysis of Molecular Variance revealed that the majority(85%)of the variance rather existed within groups than among(15%)groups.Finally,our study allowed us to select new promising mutant genotypes that could be tested for multi-locational trials to evaluate their agronomic performance.

Functional Diversity of Mycorrhizal Fungi Has Differential Effects on Salinity Tolerance of <i>Acacia seyal</i>(Del.) Seedlings

Acacia seyal is a leguminous plant that plays an important role in the ecosystem of Sahelian zone by producing gum, wood and fodder. The growth of A. seyal is subject to many constraints as salinity which can affect the development of this tree. Therefore, soil microorganisms can help A. seyal to better tolerate the effects of negative environmental stresses. The contribution of arbuscular mycorrhizal fungi (AMF) to the salt tolerance of A. seyal, was evaluated by testing the effects of eight different arbuscular mycorrhizal fungi (AMF) isolates in the performance of A. seyal seedlings subjected to different levels of salinity (0, 340 and 680 mM). The results based on growth parameters of shoot and root parts, shoot mineral N, P, K and Na content as well as survival rates and mycorrhization showed that AMF improved mineral nutrition of A. seyal seedlings during salt stress. The combination between AMF and salinity provided evidence that the efficiency of AMF isolates were variable in improving mineral nutrition and mortality rate for A. seyal seedlings related to the level of salt stress. However, the effects of inoculation were variable depending to the AMF isolate associated with seedlings and the level of salinity, suggesting that interactions between plants and AMF can be modulated by both AMF diversity and the type and level of abiotic factors. Rhizophagus intraradices was more efficient at 680 mM NaCl in plant growth and mineral uptake while Glomus deserticola did not promote a better plant development than most of the other species inoculated to seedlings.

Influence of the Size of Potato Microtubers (<i>Solanum tuberosum</i>L.) on the Yield of Plants under Semi-Axenic Conditions

The potato (Solanum tuberosum L.) is a vegetable that ranks fifth in the world for human consumption. Its importance is growing more and more in the Senegalese diet. However, the potato production in Senegal does not meet the needs of the market, which maintains dependence on the outside for the supply of quality seeds. In addition, these imported seeds do not often have phytosanitary qualities required for local production in the Sahelian zone. The in vitro production of microtubers, used as seed, has been shown to be one of the most efficient means for propagation of basic material. To overcome the constraints linked to the supply and availability of potato seeds, with high germination capacity, the impact of the microtuber size on the yield of the plants under semi-controlled conditions was examined. The pre-germinated microtubers were produced in vitro from vitroplants of 3 different varieties (Aida, Atlas, Odessa) adapted to the edaphic-climatic conditions of Senegal. The effects of the seed sizes of microtubers, greater than 4 mm, sown under semi-controlled conditions, on the yield of the plants, result in an increase in the ratio, in the vegetative development of the plants, but also in the number and size of the minitubers harvested. The yield of the plants also depends on the variety. It can therefore be envisaged to produce local potato seeds from microtubers and minitubers.

Pathogenicity of diatraea saccharalis Densovirus to Host Insets and Characterization of its Viral Genome

Diatraea saccharalis densovirus (DsDNV ) 的致病力在它的主人幼虫上被测试。结果证明直到在接种以后的 4 天，没有幼虫死亡被观察，感染的幼虫开始从第四天展出感染症状。在 5 天感染以后，感染的幼虫的累积死亡显著地增加了并且而分别地，控制组的仅仅在感染的一样的时期以后是10%和20%，在 21 天感染以后在 12 天和100%以后到达了60%，建议感染的幼虫组的高死亡由于 DsDNV 的高致病力。DsDNA 的尺寸被病毒的 DNA 分子的电子显微镜学可视化决定，土著人和 endonuclease 的胶化电气泳动消化了 DNA 碎片。本国的 DsDNA 的全部的长度是大约 5.95 kb。DsDNV DNA 与 16 限制酶被消化，那些酶的一张限制地图与 41 个限制地点被构造。Junonia coenia densovirus (JcDNV ) 和街郎 mellonella densovirus (GmDNV ) 的染色体的有那些的 DsDNV 染色体的限制地图的比较显示三个 densovirus 染色体被发现分享许多相同限制地点。因此，大多数下列 endonucleases 欺骗 H 的限制地点我， Hha 我， Xba 我， Cla 我，毒蛇 700， Spe 我， Nco 我和 Bcl 我，被发现在三个 densovirus 染色体之中被保存。在染色体的两结束印射的对称的劈开地点建议了其尺寸被估计是大约 500 bp 的转换终端重复(国际互联网广播台) 的存在。类似的染色体尺寸，几乎相同的限制地点和为这三 densoviruses 的大约 500 bp 的一个国际互联网广播台的存在建议他们属于 ambisense densoviruses 的一样的组。钥匙词致病力 - Densovirus - Diatraea saccharalis - Genomic DNA - 限制地图 CLC 数字 S852.65 基础条款：中国(30670081 ) 的国家自然科学基础；由 IRD 同意了(研究所 de 精选倒 developpement )

Response to Inoculation with Arbuscular Mycorrhizal Fungi of Two Tomato (Solanum lycopersicum L.) Varieties Subjected to Salt Stress under Semi-Controlled Conditions

Salinity is a major problem that seriously impacts agricultural production, particularly that of tomato (Solanum lycopersicum L.). However, the plant has the ability to associate with Arbuscular Mycorrhizal Fungi to better tolerate salt stress. Thus, thanks to the extension of the AMF hyphae, the hydromineral nutrition and the tolerance to excess toxic ions (Na+ and Cl-) of the plant are optimized. In this context, the contribution of AMF to the salt stress tolerance of two tomato varieties under semi-controlled conditions was studied. To do this, the frequency and intensity of mycorrhization, the relative mycorrhizal dependency, the survival rates, the aerial and root dry weights, the mineral (P, K+, Na+) and proline contents of the plants subjected to four levels of salinity [0, 70, 140 and 210 mM of NaCl] were evaluated. All the parameters assessed appeared to be dependent on the variety, the fungal strain and the NaCl concentration. With the Lady Nema variety, inoculation with the Claroideoglomus etunicatum strain at [NaCl 140 mM] resulted in the highest frequencies (54%), intensities (40.47%), and relative mycorrhizal dependencies (19.65%). This same symbiotic couple recorded high survival rates (55%) and aerial (2.03 g) and root (0.50 g) dry weights. Significant contents of K+ (Leaves: 7.5 mg⋅g-1;Roots: 4.4 mg⋅g-1 of dry matter), P (Leaves: 15.15 mg⋅g-1 of dry matter) and proline (975 nmoles⋅g-1 of fresh matter) were also recorded by this pair, with the lowest Na+ contents (Leaves: 1.93 mg⋅g-1;Roots: 0.96 mg⋅g-1 of dry matter). For the Mongal variety, at [NaCl 140 mM], the highest frequencies (50.36%), intensities (35.14%) and relative mycorrhizal dependencies (43.95%) were obtained thanks to inoculation with Rhizophagus fasciculatus. The highest survival rates (59%) and aerial (2.58 g) and root (0.79 g) dry weights were also obtained with this symbiotic couple. The contents of K+ (Leaves: 6.1 mg⋅g-1;Roots: 3.09 mg⋅g-1 of dry matter), P (Leaves: 12.49 mg⋅g-1 of dry matter) and proline (942 nmoles⋅g-1 of fresh matter) the most important and those in Na+ the lowest (Leaves: 2.03 mg⋅g-1;Roots: 1.53 mg⋅g-1 of dry matter) were also recorded for this same pair. Thus, the best fungal partner for the Lady Nema variety is C. etunicatum, followed by F. mosseae and R. fasciculatus, while for the Mongal variety it is R. fasciculatus, followed by C. etunicatum and F. mosseae.

Response to Inoculation with Arbuscular Mycorrhizal Fungi of Two Tomato (Solanum lycopersicum L.) Varieties Subjected to Water Stress under Semi-Controlled Conditions

In arid and semi-arid regions, the growth and development of cultivated plants, especially tomato (Solanum lycopersicum L.), are severely limited by water deficit. Thus, to cope with this constraint, the plant establishes symbiotic relationships with arbuscular mycorrhizal fungi (AMF) in the soil whose extension of the hyphae allows a better and deeper exploration;this notably improves the hydromineral nutrition of the plant. Therefore, the choice of fungal partner becomes crucial for the establishment of a crop in water-deficient soil. In this context, the contribution of AMF to the water stress tolerance of two varieties of tomato plants was assessed under semi-controlled conditions. Parameters, such as the mycorrhizal frequency, intensity of mycorrhization, relative mycorrhizal dependency, growth, and biochemical parameters (carbon, nitrogen, phosphorus, and proline contents) of plants subjected to three levels of water stress (T100, T70, and T30), were evaluated. The highest frequencies and intensities of mycorrhization and relative mycorrhizal dependencies were obtained with plants of the Xewel variety inoculated with Rhizophagus fasciculatus (F: 95.24%, 88.35%, and 13.64%;M: 40.52%, 37.52%, and 11.22%;D: 23.7%, 54.4%, and 78.82%) and in those of the Lady Nema variety inoculated with Claroideoglomus etunicatum (F: 95.12%, 87.01%, and 15.25%;M: 40.66%, 37.99%, and 11.42%;D: 19.27%, 57.01%, and 70.98%), respectively at water regimes of T100, T70 and T30. These same symbiotic couples recorded, at T30, the best survival rates (+ 40%) and the higher aerial (77% and 74%) and root dry weights (80% and 59%). Plants of the Xewel variety inoculated with R. fasciculatus recorded the highest contents of carbon (T70: 30.59% and T30: 21.55%) and phosphorus (T70: 0.18% and T30: 0.17%). Plants of the Lady Nema variety recorded the highest nitrogen contents with 3.51% and 3.20%, respectively at T70 and T30. Plants of the Lady Nema variety, inoculated with C. etunicatum, also recorded the highest proline contents (572.25, 739.44, and 1165 nmoles•g−1 of fresh material), followed by those of the Xewel variety inoculated with R. fasciculatus (580.36, 763.65, and 1112.11 nmoles•g−1 of fresh matter), respectively at T100, T70, and T30. For the Lady Nema variety, the best fungal partner is C. etunicatum, followed by R. fasciculatus and, finally, Funneliformis mosseae. However, for the plants of the Xewel variety, R. fasciculatus is the most efficient, followed by F. mosseae and C. etunicatum. This suggests that, in tomatoes, the efficiency of mycorrhizal symbiosis under water stress conditions is not only dependent on the host plant but on both associated symbiotic partners. Hence, it is a need for screening to identify the best symbiotic couples in a stressful environment.

Primary Characterization of a Novel Soymilk-Cashew Fermented with an Improving of Its Antioxidant and Anti-Inflammatory Contents

Cashew nut (Anacardium occidental) milk was included as a functional ingredient in soybean (Glycine max L.) milk at 20/80% and was fermented comparatively to commercial yogurt starters by two strains TC6 and A4 (recently isolated from two Ivorian highly flavored neglected traditional staple foods (beer and garlic)) identified as Weissella paramesenteroides and Enterococcus faecalis, after the screening of their probiotic, antioxydant and anti-inflammatory potentialities, respectively. The primary characterization of these plant-milks showed a strong improvement in their sensory, antioxidant and anti-inflammatory abilities. While TC6 from traditional beer Tchapalo increases anti-inflammatory activity by almost eighteen times, A4 isolated from garlic increases antioxidant activity by two times. Due to their aromatic and organosensory potentialities certainly, milks L138, L180 and 130 fermented respectively by the combination of TC6 and A4, TC4 alone and A4 alone were the most appreciated than the plant-milk fermented by the two strains of commercial yogurt. These probiotics, anti-oxidant and anti-inflammatory plant-milks should be further characterized in terms of their biological activities and tested in animal models to confirm their nutrition-health claims.

Potential Probiotic Tiger Nut-Cashew Nut-Milk Production by Fermentation with Two Lactic Bacteria Isolated from Ivorian Staple Foods

Probiotification of plant milk can improve its sensory and health-promoting properties. As traditional fermented foods where lactic acid bacteria (LAB) are present have been associated with beneficial effects on human health, the beneficial effects of two LAB recently isolated from two current Ivorian staple foods (a pepper and a traditional beer) were screened. These two strains LAC 1 (Lactobacillus plantarum) and LAC 2 (Pediococcus acidilactici) which presented probiotic, exopolysaccharides, inflammatory and anti-oxidant activities, were used to ferment a composite plant milk of tiger-nut and cashew (80/20) compared to two starters of a commercial yogourt. The obtained plant milks SCT 2 and SCT 3 with a significant increase in their antioxidant and/or anti-inflammatory activities and lactic bacteria contents were more preferred by consumers than SCT 1 obtained by fermentation of the commercial yogourt starters. The mixing of LAC 1 and LAC 2 was not beneficial. SCT 2 (with an anti-inflammatory activity of 31.38% and an anti-oxidant activity of 17.30%) and SCT 3 (with an anti-oxidant activity of 22.28) could be further tested in animal models to verify their nutrition-health claims.

GSTO基因多态性与燃煤污染型砷中毒易感性的关系

[目的]探讨GSTO基因多态性与燃煤污染型砷中毒易感性的关系。[方法]应用聚合酶链反应-限制性片段长度多态性(PCR-RFLP)技术检测130名燃煤型砷中毒患者和140名健康个体GSTO1 Ala140Asp和GSTO2 Asn142Asp基因两个位点的多态性,并分析不同基因型与砷中毒发病风险的关系。[结果]病例组中携带GSTO2 142 Ash／Asp+Asp/Asp(杂合型+突变纯合型)基因型个体的比例显著高于对照组,携带该基因型的个体较携带GSTO2 142 Asn/Asn(野生纯合型)基因型个体发生砷中毒的风险升高1．18倍(ORadj=1．18,95％CI:1．02～1．37);而病例组中携带GSTO1 140Ala／Asp+Asp／Asp(杂合型+突变纯合型)基因型个体的比例仅略高于对照组,差异无统计学意义(ORadj=0．98, 95％CI:0．51～1．91);但同时携带GSTO1 140Ala／Asp+Asp／Asp和GSTO2 142Asn／Asp+Asp／Asp基因型的个体砷中毒的发病风险显著增加(ORadj=2．48,95％CI:1．14～5．40)。[结论]携带GSTO2 Asn142Asp基因型个体有较高的砷中毒发病风险;而同时携带GSTO1 140Ala／Asp+Asp/Asp和GSTO2 142Asn/Asp+Asp／Asp的个体可能更容易发生砷中毒。

谷胱甘肽硫转移酶M1和T1基因多态性与燃煤型砷中毒发病的关系

目的探讨谷胱甘肽硫转移酶M1和T1（GSTM1、GSTT1）基因多态性与燃煤污染型砷中毒发病风险的关系。方法采用多重等位基因特异聚合酶链反应技术检测贵州省130名燃煤型砷中毒患者及140名健康个体的GSTM1和GSTT1基因多态性，并分析不同基因型与砷中毒发病的关系。结果砷中毒病例组和对照组GSTT1纯合缺失基因型（GSTT1^（-/-））的频率分别为58．5％和45．0％，组间比较差异有统计学意义（Х^2=6．246，P〈0．05）；携带GSTT1^（-/-）基因型个体发生砷中毒的风险是携带GSTT1非纯合缺失基因型（GSTT1^（＋/＋）or（-/-））个体的2．18倍[比值比（OR）adj=2．18，95％可信区间（CI）：1．183～4．018]。砷中毒病例组和对照组间GSTM1纯合缺失基因型（GSTM1^（-/-））频率的差异无统计学意义（P〉0．05）。基因型联合分析显示：携带GSTM1^（-/-）和GSTT1^（-/-）联合基因型的个体，其砷中毒的发病风险显著增加（ORadj=2．931，95％CI：1．024～8．387）。结论GSTT1^（-/-）基因型可能是燃煤型砷中毒发生的重要危险内因之一。

In <i>Vitro</i>Clonal Propagation from Adult Material of a Savannah Species of Socio-Economic Importance: <i>Annona senegalensis</i>Pers.

Annona senegalensis (Pers.) or Annone from Senegal is a species found in the West African savannah and para-littoral sands. It offers real possibilities of socio-economic use, particularly in the medical, nutritional, ecosystem conservation and poverty alleviation fields. However, this wild species remained not fully exploited despite its potentialities. As a result, there is a need to regenerate this species;therefore, the in vitro propagation from adult material was undertaken. For this purpose, axillary nodes from plant regrowth taken from elderly subjects were aseptically introduced into different media enriched or not with phytohormones. Among the 3 culture media tested, that of Murashige and Skoog (MS, 1962) was the most reactive and made it possible to develop a micropropagation protocol for adult material of A. senegalensis. Thus, the introduction of these explants in media containing cytokinins (BAP and Kinetin) significantly increased the reactivity compared to media without hormones. If the best average numbers of shoots (2.3) and nodes (5.3) are obtained in MS + BAP 2 mg·L−1, with a reactivity of 91.66%, the addition of 0.1 mg·L−1 NAA gave the best average length (8.25 cm) of vitroplants. An induction time of 3 days into darkness with IBA at 50 mg·L−1, followed by a transfer to hormone-free expression medium (MS/2) under light, resulted in a rooting rate of 58.33%. After the gradual weaning of the young plants in a mini-greenhouse, under shade for 3 weeks, 50% of the plants survived. This in vitro regeneration protocol can therefore be adopted for the clonal propagation of adult material of A. senegalensis. However, the rooting rate can be improved by trying other hormonal combinations based on auxins or by considering ex-vitro rooting during shade weaning.

<i>In Vitro</i>Clonal Propagation from Juvenile and Different Explant Types of Two Edible <i>Annonaceae</i>Species: <i>Annona muricata</i>L. and <i>Annona squamosa</i>L.

Annona muricata L. and Annona squamosa L. are tropical species whose fleshy fruit is edible. They offer real possibilities for socio-economic use, particularly in the fields of medicine, nutrition, ecosystem conservation and the poverty alleviation. This study was set up to evaluate different methods of micropropagation from juvenile material for the regeneration of these species. Thus, MS medium supplemented with [BAP 2 mg·L-1] i.e. M2 produced 2.87 newly formed shoots from the cotyledonary nodes of A. muricata. For the terminal apices of A. squamosa, it was MMS medium supplemented with [BAP 2 mg·L-1] i.e. MM2 that was most conducive to new shoot formation (3.12). The addition of 0.1 and 0.2 mg·L-1 of NAA in the M2 medium, made it possible to have the best elongations and average number of nodes for the new shoots from cotyledonary nodes of A. muricata (9.11 cm for 5.62 nodes). With A. squamosa, MM7 medium [MMS + BAP 1 mg·L-1 + KIN 1 mg·L-1] resulted in an average length of 9.05 cm with 5.62 nodes on average for the apical shoots. A 3-day rhizogenic induction period in the dark with [IBA 50 mg·L-1] and 2 g·L-1 of activated charcoal gave a rooting rate of 66.67% for shoots originating from the cotyledonary nodes of A. squamosa;while with vitroplants from cotyledonary nodes of A. muricata, a better rooting rate (83.33%) was obtained following a 5-day rhizogenic induction. After 30 days of acclimatization, the survival rate reached 83.33% for plants from the tips of A. muricata, whereas for A. squamosa, it was plants grown from cotyledonary nodes that had the same survival rate.

Maize Crop N Uptake from Organic Material of <i>Gliricidia sepium </i>Coinoculated with <i>Rhizobium</i>and Arbuscular Mycorrhizal Fungus in Sub-Saharian Africa Sandy Soil

The effect of green manure of gliricidia (Gliricidia sepium (Jacq.) Walp) leguminous plants applied for cereal maize cultivation and N uptake by cereal were investigated and analyzed in relation to influence of dual inoculation of gliricidia with microbial symbionts. Two pot experiments were conducted in greenhouse. The first trial was set up to enhance growth of gliricidia with exotic and indigenous rhizobial strains and arbuscular mycorrhizal fungus and the second to determine the effect of gliricidia organic material on maize growth. Direct 15N-labelling techniques were used to estimate N-fixed by gliricidia plant and N uptake of maize cereal crop from green manuring was calculated. Growth of gliricidia trees estimated by aboveground biomass production and N fixed were positively affected by dual inoculations. This study showed that shoot dry weight and N accumulation of maize cultivated under gliricidia green manure were influenced by its application and indirectly by microbial treatments. The N recovery by the maize accounted 17.32% to 26.52% of N applied as gliricidia organic material. Gliricidia green manure N accumulation and release, and afterward microbial inoculations were substantially determining on maize crop N uptake and growth in sandy soil of Sub-Saharian Africa.