A pot experiment was conducted to study the effects of arbuscular mycorrhizal （AM） fungi （from contaminated or uncontaminated soils） on arsenic （As） uptake of tobacco （Nicotiana tabacurn L.） in As-contaminated...A pot experiment was conducted to study the effects of arbuscular mycorrhizal （AM） fungi （from contaminated or uncontaminated soils） on arsenic （As） uptake of tobacco （Nicotiana tabacurn L.） in As-contaminated soil. Mycorrhizal colonization rate, dry weight, As and P uptake by plants, concentrations of water-extractable As and As fractions were determined. A low mycorrhizal colonization rate （〈 25%） was detected. Our research indicated that AM fungi isolated from polluted soils were no more effective than those from unpolluted soils when grown in symbiosis with tobacco. No significant differences were observed in roots and stalks dry weights among all treatments. Leaves and total plant dry weights were much higher in Glomus versiforme treatment than that in control treatment. As contents in roots and stalks from mycorrhizal treatments were much lower than that from control treatment. Total plant As content exhibited the same trend. P concentrations in tobacco were not affected by colonization, nor were stalks, leaves and total plant P contents. Roots P contents were remarkably lower in HN treatments than in other treatments. Meanwhile, decreased soil pH and lower water-extractable As concentrations and higher levels of As fraction bound to well-crystallized hydrous oxides of Fe and AI were found in mycorrhizal treatments than in controls. The protective effect of mycorrhiza against plant As uptake may be associated with changes in As solubility mediated by changing soil pH. These results indicated that under As stress, proper mechanisms employed by AM fungi can protect tobacco against As uptake. Results confirmed that AM fungi can play an important role in food quality and safety.展开更多
为明确落羽杉属树木赤枯病的致病菌种类,对采自南京中山植物园及周边地区的病叶进行病原菌分离,结合形态学特征与分子生物学技术对其进行鉴定,并分析病原菌的生物学特性。结果表明,共获得9种菌种,分别标号为1~9,其中2号菌株检出率最高,...为明确落羽杉属树木赤枯病的致病菌种类,对采自南京中山植物园及周边地区的病叶进行病原菌分离,结合形态学特征与分子生物学技术对其进行鉴定,并分析病原菌的生物学特性。结果表明,共获得9种菌种,分别标号为1~9,其中2号菌株检出率最高,占总数的36.40%,用该菌株侵染健康叶片后发病症状与自然发病症状一致,并可再次分离到2号菌株,符合柯赫氏法则;形态学鉴定结果显示,病原菌分生孢子为梭形、直或弯曲,5个细胞,顶胞和尾胞均为圆锥形,无色透明;r DNA-ITS序列分析结果表明,该菌株与斑污拟盘多毛孢Pestalotiopsis maculans同源性最高,为99.00%。结合形态特征与分子鉴定最终确定落羽杉赤枯病病原菌为斑污拟盘多毛孢。生物学特性分析结果表明,该病原菌在25℃、p H 6~7的PDA培养基上长势最好;在以淀粉为碳源、谷氨酸为氮源的培养基上生长最快。展开更多
Arsenic （As） contamination has become the environment issue of global concern. In China, large area of farmland and the site soil were contaminated by As, which means that suitable remedying methods were urgently ne...Arsenic （As） contamination has become the environment issue of global concern. In China, large area of farmland and the site soil were contaminated by As, which means that suitable remedying methods were urgently needed. Phytoremediation, as one of environment-friendly soil remediation techniques developed in recent years, shows a bright future for the remediation of As contaminated soils. However, phytoremediation efficiency needs to be enhanced further because of low concentration of bio- available As in the soils. A triangle flask culture experiment was carried out to study the effects of functional species, isolated from As-polluted soils, that could improve As mobility from the soil. These species included two bacilli, B 1 and B2 （Breviba- cillus） and two fungi, F1 （Trichoderma）, F2 （Fusarium）. They could transform the concentration of As fractionation in the soil sterilized by the method of 6~Co-T ray. Through the experiment, the concentrations of non-specifically-sorbed and specifical- ly-sorbed As fractionation, and pH value of culture solution with inoculated treatment were higher than that with the control. Especially, the concentration of non-specifically-sorbed As fractionation in the treatment-inoculated species was 2 to 6 times higher than that of non-inoculation treatment. Moreover, two bacilli and two fungi could produce IAA, which was conducive to the plant survival when they were jointly used in remedying the As-contaminated soil.展开更多
基金supported by the Innovative Research International Partnership Project of Chinese Academy of Science (No.CXTD-Z2005-4)
文摘A pot experiment was conducted to study the effects of arbuscular mycorrhizal （AM） fungi （from contaminated or uncontaminated soils） on arsenic （As） uptake of tobacco （Nicotiana tabacurn L.） in As-contaminated soil. Mycorrhizal colonization rate, dry weight, As and P uptake by plants, concentrations of water-extractable As and As fractions were determined. A low mycorrhizal colonization rate （〈 25%） was detected. Our research indicated that AM fungi isolated from polluted soils were no more effective than those from unpolluted soils when grown in symbiosis with tobacco. No significant differences were observed in roots and stalks dry weights among all treatments. Leaves and total plant dry weights were much higher in Glomus versiforme treatment than that in control treatment. As contents in roots and stalks from mycorrhizal treatments were much lower than that from control treatment. Total plant As content exhibited the same trend. P concentrations in tobacco were not affected by colonization, nor were stalks, leaves and total plant P contents. Roots P contents were remarkably lower in HN treatments than in other treatments. Meanwhile, decreased soil pH and lower water-extractable As concentrations and higher levels of As fraction bound to well-crystallized hydrous oxides of Fe and AI were found in mycorrhizal treatments than in controls. The protective effect of mycorrhiza against plant As uptake may be associated with changes in As solubility mediated by changing soil pH. These results indicated that under As stress, proper mechanisms employed by AM fungi can protect tobacco against As uptake. Results confirmed that AM fungi can play an important role in food quality and safety.
文摘为明确落羽杉属树木赤枯病的致病菌种类,对采自南京中山植物园及周边地区的病叶进行病原菌分离,结合形态学特征与分子生物学技术对其进行鉴定,并分析病原菌的生物学特性。结果表明,共获得9种菌种,分别标号为1~9,其中2号菌株检出率最高,占总数的36.40%,用该菌株侵染健康叶片后发病症状与自然发病症状一致,并可再次分离到2号菌株,符合柯赫氏法则;形态学鉴定结果显示,病原菌分生孢子为梭形、直或弯曲,5个细胞,顶胞和尾胞均为圆锥形,无色透明;r DNA-ITS序列分析结果表明,该菌株与斑污拟盘多毛孢Pestalotiopsis maculans同源性最高,为99.00%。结合形态特征与分子鉴定最终确定落羽杉赤枯病病原菌为斑污拟盘多毛孢。生物学特性分析结果表明,该病原菌在25℃、p H 6~7的PDA培养基上长势最好;在以淀粉为碳源、谷氨酸为氮源的培养基上生长最快。
基金supported by the National Natural Science Foundation of China (Grant Nos. 21307080 and 41101232)Shanghai Knowledge Service Platform (Grant No. ZF1224)Key Discipline Construction Projects of Shanghai Second Polytechnic University (Grant No. XXKYS1404)
文摘Arsenic （As） contamination has become the environment issue of global concern. In China, large area of farmland and the site soil were contaminated by As, which means that suitable remedying methods were urgently needed. Phytoremediation, as one of environment-friendly soil remediation techniques developed in recent years, shows a bright future for the remediation of As contaminated soils. However, phytoremediation efficiency needs to be enhanced further because of low concentration of bio- available As in the soils. A triangle flask culture experiment was carried out to study the effects of functional species, isolated from As-polluted soils, that could improve As mobility from the soil. These species included two bacilli, B 1 and B2 （Breviba- cillus） and two fungi, F1 （Trichoderma）, F2 （Fusarium）. They could transform the concentration of As fractionation in the soil sterilized by the method of 6~Co-T ray. Through the experiment, the concentrations of non-specifically-sorbed and specifical- ly-sorbed As fractionation, and pH value of culture solution with inoculated treatment were higher than that with the control. Especially, the concentration of non-specifically-sorbed As fractionation in the treatment-inoculated species was 2 to 6 times higher than that of non-inoculation treatment. Moreover, two bacilli and two fungi could produce IAA, which was conducive to the plant survival when they were jointly used in remedying the As-contaminated soil.
