抗白粉病小麦新种质的选育及细胞学鉴定     

王黎明  李本  李萍  李兴锋  王洪刚 《种子》2008,27(2):10-12

利用杂交、回交、自交相结合的方法从小麦烟农15与中问偃麦草（Thinopyrum intermedium（Host）Bark worth and Dewey,ElE1E2E2StSt,2n=6x=42）杂交后代（BC3F6）中选出抗白粉病种质系SN 996221。在对其白粉病抗性等主要农艺性状鉴定的基础上,进行了细胞学分析。结果表明：SN996221高抗小麦白粉病,其抗性可能来源于中问偃麦草;其根尖细胞染色体数目为2n=42,花粉母细胞减数分裂中期I（PMC MI）染色体构型为2n=21Ⅱ,与普通小麦的杂种F1PMC M I大多数细胞能观察到2个单价体,染色体构型为2n=1.02I＋20.49Ⅱ,SN 996221可能是一个小麦一中间偃麦草的异代换系。  相似文献   

不同杀虫剂对稻纵卷叶螟和稻飞虱的防治效果   总被引：1，自引：0，他引：1  

冯成玉  Yu Baofu  陆晓峰  吉用铨  Meng Aizhong  贲秀兰 《作物杂志》2008,(4)

选取含有不同有效成分的12种杀虫剂,在第四（2）代稻纵卷叶螟二三龄幼虫盛期和稻飞虱的卵孵盛期进行了田间用药试验。结果表明：氟虫腈和含有氟虫腈成分的复配药剂,对稻纵卷叶螟和稻飞虱均表现出良好的速效性和持效性,控害效果也相对较高。毒死蜱与氟虫腈或与阿维菌素复配,可达到优势互补,即保持良好速效性的同时,其持效性可得到明显提高;在稳定防治效果的基础上,各药剂有效成分的使用量可明显降低。  相似文献   

Change in soil properties and the soil microbial community following land spreading of olive mill wastewater affects olive trees key physiological parameters and the abundance of arbuscular mycorrhizal fungi     

Beligh Mechri  Fethi Ben Mariem  Mohamed Baham  Salem Ben Elhadj  Mohamed Hammami 《Soil biology & biochemistry》2008,40(1):152-161

Olive mill wastewater (OMW) constitutes a major environmental problem for Mediterranean countries, where most of the world olive oil production takes place. The recycling of the OMW and its use as water for irrigation in agriculture, provided that its impact on soil and plant is established, is an attractive possibility for the Mediterranean countries. Investigations were performed on the influence of agronomic application of OMW (amount applied: 30, 60, 100 and 150 m³ ha^?1) in a field of olive trees on trees characters (photosynthesis, root-soluble carbohydrate and root colonisation), soil properties, and soil microbial community structure. Specific attention was paid to arbuscular mycorrhizal (AM) fungi. The soil fatty acid methyl ester (FAME) 16:1ω5 was used to quantify biomass of AM fungi and the root FAME 16:1ω5 analysis was used as index for the development of colonisation in the olive trees roots. A significant increase in organic C, C/N ratio, extractable phosphorus and exchangeable potassium was found after one year of agronomic application of OMW. The development of saprophytic fungi was significantly higher in the OMW amended soils, whereas the abundance of the soil FAME 16:1ω5, root FAME 16:1ω5, photosynthetic rates and the amount of the total root-soluble carbohydrate were decreased significantly after agronomic application of OMW. A principal component analysis (PCA) of the trees characteristics profiles showed discrimination between the nonirrigated and the OMW irrigated olive trees. These findings suggest that the altering functioning of arbuscular mycorrhizas should be considered as potential factors mediating olive trees responses to agronomic application of OMW when the OMW dose applied is higher than 30 m³ ha^?1. To our knowledge, this is the first report of alterations in the soil FAME 16:1ω5 and root FAME 16:1ω5 due to land spreading of OMW.  相似文献   

Reduced tillage effects on physical properties of silt loam soils growing root crops   总被引：2，自引：1，他引：1  

Karoline D&#x;Haene  Jan Vermang  Wim M. Cornelis  Ben L.M. Leroy  Wouter Schiettecatte  Stefaan De Neve  Donald Gabriels  Georges Hofman 《Soil & Tillage Research》2008,99(2):279-290

In the scope of the increasing concern for soil conservation, reduced tillage (RT) agriculture is growing more important in today's agriculture in Western Europe. However, crop rotations often include beets and potatoes, crops that are generally assumed to be less suitable under RT agriculture because they result in a high disturbance of the soil at the formation of the ridges and at harvest. Therefore, the short- and long-term effect of RT agriculture on bulk density (BD), water retention curve (WRC), aggregate stability and field-saturated hydraulic conductivity of silt loam soils with crop rotations including root crops was evaluated. Ten fields at seven locations representing the important RT types, applied for a different number of years, and eight fields under conventional tillage (CT) agriculture with similar soil type and crop rotation were selected. At each location, BD of the 5–10 cm layer was mostly lower in the RT fields (1.42 ± 0.05 Mg m⁻³ [average with standard deviation]) compared to the CT fields (1.44 ± 0.09 Mg m⁻³) and the water content at saturation was mostly higher (0.394 ± 0.027 m³ m⁻³ and 0.382 ± 0.021 m³ m⁻³ for RT and CT fields, respectively). No differences in BD (1.53 ± 0.03 Mg m⁻³) or WRC could be found in the 25–30 cm soil layer when comparing the RT with the CT fields. The stability index of the 0–10 cm layer measured by ‘dry and wet sieving’ [De Leenheer, L., De Boodt, M., 1959. Determination of aggregate stability by the change in mean weight diameter. Mededelingen van landbouwhogeschool en de opzoekingstations van de staat te Gent 24, 290–300] was 40% higher under RT than CT agriculture. The mean weight diameter (MWD) [Le Bissonnais, Y., 1996. Aggregate stability and assessment of soil crustability and erodibility: I. Theory and methodology. Eur. J. Soil Sci. 47, 425–437] was significantly higher even after short-term RT compared to CT agriculture. The MWD after a heavy shower, a slow wetting of the soil and stirring the soil after prewetting was 19%, 38% and 34% higher for RT than CT fields, respectively. The field-saturated hydraulic conductivity tended to be higher under RT compared to the CT fields. Despite the high disturbance of the soil every 2 or 3 years of crop rotations including sugar beets or potatoes, RT agriculture had a positive effect on the investigated physical soil properties.  相似文献   

Salt stress effects on enzymes activities involved in carbon metabolism and nitrogen availability of two Tunisian durum wheat varieties     

Rim Ben Mansour  Rihab Ben Fattoum  Houda Gouia  Chiraz Chaffei Haouari 《Journal of plant nutrition》2019,42(10):1142-1151

Two varieties of durum wheat (Om Rabiaa and Karim), were analyzed and evaluated in the presence of increasing doses of NaCl (0, 100, 200 and 300?mM) in which we added different concentrations of nitrate (0.1, 3, 10?mM). The data obtained showed that presence of NaCl in the culture medium induces the increase of the salt accumulation levels (Na⁺, Cl^?) and reduces the levels of K⁺ and NO₃^? in the cultivar Om Rabiaa. In Karim variety, ions that have been heavily accumulated following exposure to NaCl are Na⁺ and K⁺ while low levels of NO₃^? and Cl^? have been detected. Those findings highlight the difference in the salinity tolerance of durum wheat cultivars also depending on nitrogen (N) availability, Karim cultivar being less sensitive to NaCl treatment than Om Rabiaa. These data also suggested a relationship between salt tolerance capacity and enhancement of nitrogen and carbon metabolisms enzyme activity.  相似文献   

Changes in phytochemical, antimicrobial and free radical scavenging activities of the Peruvian pepper tree (Schinus molle L.) as influenced by fruit maturation     

Karim Hosni  Marwa JemliSalma Dziri  Yacine M’rabetAsma Ennigrou  Ahlem SghaierHervé Casabianca  Emmanuelle VullietNadia Ben Brahim  Houcine Sebei 《Industrial Crops and Products》2011,34(3):1622-1628

The effect of stage of maturity on total lipids, fatty acids, yields and essential oil composition and their antimicrobial and free radical scavenging activities of the Schinus molle fruits was investigated. The content of total lipids varied from 2.87 to 5.35% (w/w, dw) and were rich in unsaturated fatty acids particularly linoleic acid. As maturation progress, the essential oil yield dropped from 5.18% to 1.15%. Monoterpene hydrocarbons with α-phellandrene (35.15-40.38%), limonene + β-phellandrene (21.47-36.62%), β-myrcene (7.61-24.96%) and α-pinene (1.92-2.58%) were found to be the main components. At the same time, the essential oils were evaluated for their antimicrobial and free radical scavenging activities. They were found to be active against Bacillus subtilis, Bacillus cereus, Salmonella typhymurium and Escherichia coli but they do not inhibit the growth of Candida albicans. Conversely, they showed very weak activity against the DPPH radical. In both assay, the oil derived from the intermediate stage was reported as more efficient.  相似文献   

推广新型农业科技 大力发展节约型农业     

贲守花 《北京农业》2011,(18):154-155

为改善农民的生存环境,搞好农村新型清洁能源的开发利用,减缓全社会能源紧张局面,沼气作为优质可再生能源,具有不可比拟的优点,必须重视起来。  相似文献   

Pollination dynamics in a Douglas-fir seed orchard as revealed by pedigree reconstruction   总被引：1，自引：0，他引：1  

Ben Sk Lai  Tomas Funda  Cherdsak Liewlaksaneeyanawin  Jaroslav Klápště  Annette Van Niejenhuis  Cathy Cook  Michael U. Stoehr  Jack Woods  Yousry A. El-Kassaby 《Annals of Forest Science》2010,67(8):808-808

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妊娠期牦牛肉阜间区子宫腺的形态计量学分析     

刘辑  崔燕  胡俊伟  余四九 《中国兽医学报》2010,30(12)

运用形态计量学方法对31头牦牛肉阜间区子宫腺的相关组织学数据进行了测定,并进行统计分析。研究发现,除了妊娠151~180 d,牦牛肉阜间区子宫腺上皮高度随着妊娠时间的增长极显著降低(P0.01);妊娠期子宫腺管周长和面积非常明显增大(P0.01);不同妊娠阶段之间体积密度差异极显著(P0.01),先增加后下降,而表面密度无显著差异(P0.05);除了妊娠151~180 d,扭曲腺管和管状腺管的比例随着妊娠时间的增长分别非常显著地增大或减小(P0.01);分泌腺管的比例在妊娠期间有明显变化(P0.05),牦牛肉阜间区还存在嵌套腺管。结果显示,妊娠期牦牛肉阜间区子宫腺形态结构有明显的变化,子宫腺变的更大、更长,形状更加扭曲。  相似文献   

Sap flow measurement by a single thermal dissipation probe: exploring the transient regime     

Imen Mahjoub  Mohamed M. Masmoudi  Jean P. Lhomme  Netij Ben Mechlia 《Annals of Forest Science》2009,66(6):608-608

? In thermal dissipation method the stationary regime is used to estimate sap flow density from the temperature difference between a heating probe and a non-heating one.

? A new approach, based on the non-stationary regime of a single heating probe, is investigated on an olive tree branch. Probe temperature is monitored for different flow densities and for heating and cooling modes. Measurement sequences of 10 min using 5 s time steps are made just after the heating is switched on or off.

? Results show that temperature variation has a quasi-exponential phase whose duration decreases for increasing flow densities. Thermal indices using temperature of the probe measured at initial, final, and intermediate times t _i were developed. Relationships between sap flow density and thermal indices were found to be linear for t_i = 10 s?60 s with better coefficients of determination in cooling mode (R ² = 0.94–0.96) than in heating (R ² = 0.83–0.93). Validation tests confirmed the robustness of the single probe method with lowest error obtained for t _i = 20 s.

? Single probe method seems to be a promising technique to measure tree sap flow. Its application could be considered under cooling mode using t _i = 20 s and relatively short measurement sequences e.g. 5–10 min.

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