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81.
C E Schaedler N R Burgos J A Noldin E A Alcober R A Salas D Agostinetto 《Weed Research》2015,55(5):482-492
Fimbristylis miliacea, a weed in rice, has evolved resistance to acetolactate synthase (ALS) inhibitors. This study aimed to investigate the competitive abilities of ALS‐resistant (R) and ALS‐susceptible (S) F. miliacea with rice. A replacement series experiment was conducted in the glasshouse at the Federal University of Pelotas, Brazil. The proportions of rice to F. miliacea were 100:0, 75:25, 50:50, 25:75 and 0:100, with 1060 plants m?2. The experimental units were arranged in a completely randomised design with four replications. A follow‐up study was conducted at the University of Arkansas, Fayetteville, USA, in a split‐plot design with four replications. The main plot was species mixture (rice × R, rice × S, R × S). The subplot was competition partitioning (below‐ and above‐ground, below‐ground only, above‐ground only and no interspecific competition). Leaf area, plant height and shoot dry mass were recorded. Rice was more competitive than the R or S F. miliacea. In equal proportions of rice and F. miliacea, regardless of ecotype, the relative leaf area, height and dry mass of rice were greater than that of F. miliacea. The ALS‐resistant ecotype was less competitive with rice than the S ecotype. Intraspecific competition among rice plants was stronger than rice competition with F. miliacea. Competition for below‐ground resources was the most critical aspect of interference among rice and F. miliacea. In production fields, high infestation levels of F. miliacea results in significant yield losses; thus, resistance to ALS inhibitors needs to be curtailed. 相似文献
82.
信息资源共建共享是高校图书馆信息资源建设的重要内容。文章通过对黑龙江省高校图书馆信息资源共建共享现状进行调查和分析,总结信息资源共建共享存在的问题,并且提出实现黑龙江省高校图书馆信息资源共建共享的建设策略。 相似文献
83.
84.
陕甘宁青蒙相邻干旱地区近530年旱涝灾害、突变分析及其趋势预测 总被引:4,自引:1,他引:3
本文以研究范围内有代表性的 1 3个气象台站自 1 470年至 2 0 0 0年旱涝等级资料为基础 ,采用平均旱涝等级值和旱涝灾害指数作为旱涝灾害的指标 ,较确切地反映出该研究范围内各年旱涝灾害轻重的程度 ;凭籍 L epage检验、功率谱等方法 ,对近 5 30年的不同时间尺度的阶段性、周期性和突变特点进行了分析 ;引进均生函数累加延拓的时序建模方案 ,对该区的旱涝灾害序列有很好的拟合和预测效果。 相似文献
85.
Serum cobalamin concentrations in healthy cats and cats with non-alimentary tract illness in Australia 总被引:1,自引:1,他引:0
Objective To determine a reference range for serum cobalamin concentration in healthy cats in Australia using a chemiluminescent enzyme immunoassay and to prospectively investigate the prevalence of hypocobalaminaemia in cats with non-alimentary tract disease.
Design Prospective study measuring serum cobalamin concentrations in clinically healthy cats and cats with non-alimentary tract illness.
Procedure Blood was collected from 50 clinically healthy cats that were owned by staff and associates of Veterinary Specialist Services or were owned animals presented to Creek Road Cat Clinic for routine vaccination. Blood was collected from 47 cats with non-alimentary tract illness presented at either clinic. Serum cobalamin concentration was determined for each group using a chemiluminescent enzyme immunoassay.
Results A reference range for Australian cats calculated using the central 95th percentile in the 50 clinically healthy cats was 345 to 3668 pg/mL. Median serum cobalamin concentration in 47 cats with non-alimentary tract illness (1186 pg/mL; range 117–3480) was not significantly different to the median serum cobalamin of the 50 healthy cats (1213 pg/mL, range 311–3688). Using the calculated reference range one sick cat with non-alimentary tract illness had a markedly low serum cobalamin concentration.
Conclusion Although hypocobalaminaemia is uncommon in sick cats with non-alimentary tract illness in Australia, its occurrence in this study warrants further investigation. 相似文献
Design Prospective study measuring serum cobalamin concentrations in clinically healthy cats and cats with non-alimentary tract illness.
Procedure Blood was collected from 50 clinically healthy cats that were owned by staff and associates of Veterinary Specialist Services or were owned animals presented to Creek Road Cat Clinic for routine vaccination. Blood was collected from 47 cats with non-alimentary tract illness presented at either clinic. Serum cobalamin concentration was determined for each group using a chemiluminescent enzyme immunoassay.
Results A reference range for Australian cats calculated using the central 95th percentile in the 50 clinically healthy cats was 345 to 3668 pg/mL. Median serum cobalamin concentration in 47 cats with non-alimentary tract illness (1186 pg/mL; range 117–3480) was not significantly different to the median serum cobalamin of the 50 healthy cats (1213 pg/mL, range 311–3688). Using the calculated reference range one sick cat with non-alimentary tract illness had a markedly low serum cobalamin concentration.
Conclusion Although hypocobalaminaemia is uncommon in sick cats with non-alimentary tract illness in Australia, its occurrence in this study warrants further investigation. 相似文献
86.
斯氏副柔线虫rDNA-ITS片段的克隆及序列分析 总被引:3,自引:1,他引:2
运用PCR方法以保守引物NC5、NC13、NC13r和NC2扩增从内蒙古地区骆驼皱胃分离的3条斯氏副柔线虫(Parabronema skrjabini)rDNA的内转录间隔区1(ITS1)、5.8S序列和内转录间隔区2(ITS2)。将PCR扩增出的片段纯化后克隆至pGM-T载体,用PCR技术及酶切鉴定阳性菌落,对阳性菌落质粒DNA进行测序。结果表明线虫1(P.sk1)扩增的ITS片段大小为837 bp,包含部分的18S、28S及全部的ITS1(298 bp)、5.8S(157 bp)及ITS2(281 bp)序列;线虫2(P.sk2)扩增的ITS1片段大小为372 bp,包含部分的18S、5.8S及全部的ITS1(296 bp);线虫3(P.sk3)扩增的ITS2片段大小为484 bp,包含部分的5.8S、28S及全部的ITS2(284 bp)序列。同其它属线虫同源性比较ITS2序列同源性在30.2%-60.1%。本研究系首次报道骆驼斯氏副柔线虫的ITS序列,为斯氏副柔线虫分子生物学的进一步研究奠定基础。 相似文献
87.
Dueñas M Salas E Cheynier V Dangles O Fulcrand H 《Journal of agricultural and food chemistry》2006,54(1):189-196
The physicochemical properties of 8,8-methylmethine catechin-malvidin 3-O-glucoside isomers, commonly referred to as catechin-ethyl-malvidin 3-O-glucoside, have been studied in aqueous solutions and compared with those of the parent anthocyanin (malvidin 3-O-glucoside). The hydration and acidity constants (pKh and pKa) of the catechin-ethyl-malvidin 3-O-glucoside pigments and malvidin 3-O-glucoside were determined by UV-visible spectroscopic measurements. The ethyl-linked catechin-malvidin 3-O-glucoside pigments present higher stability toward hydration than the parent anthocyanin. The high resistance of these ethyl-linked pigments toward the hydration is related to the self-association that offers optimal protection from the nucleophilic attack of water. Moreover, the ethyl link may confer to the molecule enough flexibility to undergo intramolecular interaction, further protecting it from hydration and bisulfite discoloration. In the wine pH range (3.2-4.0), due to the low pKa and high pKh values, the ethyl-linked pigments are present as colored forms (flavylium cation and quinonoid bases). 相似文献
88.
89.
内蒙古苏尼特右旗草原土壤营养元素有效态含量分析 总被引:2,自引:0,他引:2
本研究选择内蒙古苏尼特右旗天然草场主要6个草场类,8个草场型,分析了0~30 cm土壤营养元素(全N、P、K、Ca、Mg、S、Fe、Mn、Cu、Zn、B和Mo)有效态含量及与土壤有机质、pH值之间的相互关系。结果表明,1)研究区土壤pH(8.84±0.23),均为碱性土壤;土壤有机质含量与全N含量均较低,平均分别为(9.92±4.65) g/kg和(0.46±0.25) g/kg;营养元素有效态含量积累顺序为:河泛地、湖盆低地盐生草甸草场类>荒漠草原草场区“小针茅+无芒隐子草+葱属”植被型>沙丘植被草场类,河泛地、湖盆低地盐生草甸草场类土壤矿质元素有效态含量显著高于其他草场类。2)土壤富含K元素,B和Mo处于严重缺乏状态;除了河泛地、湖盆低地盐生草甸草场类以外草场类微量元素含量均处于轻度缺乏或缺乏状态。3)土壤pH与土壤N、P、Ca、Mn和Cu元素有效量存在显著负相关性关系;土壤有机质则与土壤N、P、Ca、S、Fe、Mn和Cu元素有效量存在极显著正相关性关系。 相似文献
90.