We investigated the meta-gabbronorites in Liangcheng and used detailed petrography,geochemistry,zircon geochronological and in-situ Hf isotopic studies to clarify their formation and metamorphic ages,petrogenesis,tect...We investigated the meta-gabbronorites in Liangcheng and used detailed petrography,geochemistry,zircon geochronological and in-situ Hf isotopic studies to clarify their formation and metamorphic ages,petrogenesis,tectonic setting and provide constraints on the tectonic evolution of Khondalite Belt(KB).The zircon U-Pb dating results show that the meta-gabbronorites crystallized at~1.94 Ga and were metamorphosed at~1.91–1.89 Ga.They can be subdivided into the low-Mg and high-Mg groups.The low-Mg meta-gabbronorites contain relatively lower MgO and higher SiO2 contents than high-Mg meta-gabbronorites.They are enriched in light rare earth elements and large ion lithophile elements,depleted in high field strength elements,and exhibit positive(high-Mg meta-gabbronorites)and negative(low-Mg metagabbronorites)Sr and Eu anomalies.The zircon in-situεHf(t)of meta-gabbronorites is 0.07–4.12,with Hf model ages(TDM)of 2169–2400 Ma.The meta-gabbronorites in Liangcheng originated from the asthenospheric mantle and experienced fractional crystallization of olivine,orthopyroxene,clinopyroxene,and plagioclase.They were contaminated by the crustal rocks(mainly khondalite series)during ascent,especially for low-Mg gabbronorites.The ridge subduction is the most plausible tectonic setting for meta-gabbronorites,indicating the eastern segment of KB was in a ridge subduction setting at~1.94 Ga following an orogenic thickening event during a prolonged orogenic process.展开更多
文摘玉米穗腐病是严重的世界性真菌病害,而轮枝镰刀菌Fusarium verticillioide是我国玉米穗腐病的主要致病菌。为明确叶菌唑在我国玉米穗腐病防治中的应用潜力,采用菌丝生长速率法和孢子萌发法,分别测定了叶菌唑对2019至2021年采自我国山东、河南和江苏3个省份的35株轮枝镰刀菌菌丝生长以及分生孢子形成、萌发和芽管伸长的影响,并测定了该药剂对轮枝镰刀菌产毒(B族伏马毒素,type B fumonisins,FBs)能力及产毒基因表达的影响;通过测定叶菌唑处理后轮枝镰刀菌菌丝麦角甾醇、胞内甘油和丙二醛(MDA)含量以及电导率的变化,探究了其作用机制;同时评价了叶菌唑对田间玉米穗腐病的防治效果。结果显示:叶菌唑对35株轮枝镰刀菌均表现出较强的抑制活性,其对轮枝镰刀菌的菌丝生长以及分生孢子形成、萌发及芽管伸长具有显著的剂量依赖性抑制作用。其中:叶菌唑抑制菌丝生长的EC_(50)值在0.005~0.029μg/mL之间,平均EC_(50)值为(0.012±0.006)μg/mL;EC_(50)浓度的叶菌唑对轮枝镰刀菌分生孢子形成、萌发及芽管伸长的平均抑制率分别为(20.59±5.75)%、(24.88±5.15)%和(59.98±9.11)%;叶菌唑能显著降低轮枝镰刀菌FBs毒素的产生量和与毒素生物合成相关基因的表达水平,其对FBs毒素合成的抑制率为29.04%;显著降低了轮枝镰刀菌菌丝麦角甾醇的合成量,抑制率为39.10%,同时提高了其胞内甘油、丙二醛含量以及相对电导率,对甘油和丙二醛的诱导率分别为66.39%和33.74%。田间试验表明,有效成分90、135和180 g/hm2剂量的叶菌唑对玉米穗腐病的防效分别为(20.93±4.65)%、(27.75±5.71)%和(46.05±9.90)%,增产率分别为(8.86±8.84)%、(17.28±11.91)%和(33.20±12.07)%,均优于对照药剂丙硫菌唑•戊唑醇。本研究评估了叶菌唑防治玉米穗腐病的潜力,并可为了解其对轮枝镰刀菌的活性和作用机制提供理论依据。
基金granted by the National Natural Science Foundation of China(Grant Nos.41872194,41872203)the Regional Geological Survey Project of Huai′an,Hebei-Liangcheng,Inner Mongolia(Grant No.DD20190035)。
文摘We investigated the meta-gabbronorites in Liangcheng and used detailed petrography,geochemistry,zircon geochronological and in-situ Hf isotopic studies to clarify their formation and metamorphic ages,petrogenesis,tectonic setting and provide constraints on the tectonic evolution of Khondalite Belt(KB).The zircon U-Pb dating results show that the meta-gabbronorites crystallized at~1.94 Ga and were metamorphosed at~1.91–1.89 Ga.They can be subdivided into the low-Mg and high-Mg groups.The low-Mg meta-gabbronorites contain relatively lower MgO and higher SiO2 contents than high-Mg meta-gabbronorites.They are enriched in light rare earth elements and large ion lithophile elements,depleted in high field strength elements,and exhibit positive(high-Mg meta-gabbronorites)and negative(low-Mg metagabbronorites)Sr and Eu anomalies.The zircon in-situεHf(t)of meta-gabbronorites is 0.07–4.12,with Hf model ages(TDM)of 2169–2400 Ma.The meta-gabbronorites in Liangcheng originated from the asthenospheric mantle and experienced fractional crystallization of olivine,orthopyroxene,clinopyroxene,and plagioclase.They were contaminated by the crustal rocks(mainly khondalite series)during ascent,especially for low-Mg gabbronorites.The ridge subduction is the most plausible tectonic setting for meta-gabbronorites,indicating the eastern segment of KB was in a ridge subduction setting at~1.94 Ga following an orogenic thickening event during a prolonged orogenic process.
