Echinochloa crus-galli, one of the world＇s most serious weeds, influences seriously the yield and quality of cereal crop plant.It is well known that E.crus-galli grain is dormant, but its dormant type, as well as its...Echinochloa crus-galli, one of the world＇s most serious weeds, influences seriously the yield and quality of cereal crop plant.It is well known that E.crus-galli grain is dormant, but its dormant type, as well as its dormancy release and germination in relation to galactomannan-hydrolysing enzyme activity were poorly understood.The cooperation of endo-β-mannanase（EC 3.2.1.78）, β-mannosidase（EC 3.2.1.25） and α-galactosidase（EC 3.2.1.22） can hydrolyze the cell walls rich in mannan-based polymers.In the present paper, the mature grains are used as experimental materials, we investigated the water uptake of grains, the effect of removing partial endosperm, after-ripening, stratification and phytohormone on grain germination, and the change in endo-β-mannanase, β-mannosidase and α-galactosidase activities of grains during after-ripening and germination.The results showed that the freshly-collected grains were water-permeable and had only phase I and II of water uptake, while the grains after-ripened for 150 d had an obvious phase III of water uptake.In alternating photoperiod, the germination of grains freshly-collected was zero at 10–35°C, and that of half grains was 11% at 20°C only.The grain germination was notably promoted by after-ripening and stratification, but not by gibberellic acid and 6-benzyladenine at 0.0001–1 mmol L–1.β-Mannosidase activity increased during 0 to 300 d of after-ripening and then decreased.The activity of endo-β-mannanase and α-galactosidase of grains decreased with after-ripening.During grain germination, endo-β-mannanase and β-mannosidase activities obviously increased, while α-galactosidase activity decreased.Our data showed that E.crus-galli grain was a deep physiological dormant, the dormancy release by after-ripening was related to an increasing β-mannosidase activity, and its germination was closely associated with an increasing endo-β-mannanase and β-mannosidase activity; which have provided new knowledge to decrease the harm of E.crus-galli on production of cereal crop plant.展开更多
Exserohilum monoceras （Drechsler） Leonard and Suggs is a potential biocontrol agent for the control of Echinochloa species. This fungus causes leaf blight in Echinochloa species, but does not damage rice. Phytotoxic...Exserohilum monoceras （Drechsler） Leonard and Suggs is a potential biocontrol agent for the control of Echinochloa species. This fungus causes leaf blight in Echinochloa species, but does not damage rice. Phytotoxicity of the fungal fermented broth was evaluated through the bioassay and the active ingredients were preliminarily isolated by using silica gel column chromatography （CC） in this study. The most active fraction 5-Ⅲ was obtained and analyzed by gas chromatography-mass spectrometry （GC-MS）. The results show that 5-Ⅲ consisted of many compounds, in which 36 compounds accounted for 94.24% of total peak area. Di-n-butyl phthalate （DBP） displayed the highest activity accounted for 9.24% of the total peak area, suggesting that DBP may be one of the main active compounds produced by E. monoceras.展开更多
采集了浙江、福建、江苏、湖南、湖北、四川、重庆、黑龙江、河南9个省的稗(Echinochloa crus-galli(L.)P.Beauv.)及其变种的33份种子,分别播种在相同的环境下,获得33个种群,测定了种群的16个形态性状,筛选出重复性好的9条ISSR引物,从3...采集了浙江、福建、江苏、湖南、湖北、四川、重庆、黑龙江、河南9个省的稗(Echinochloa crus-galli(L.)P.Beauv.)及其变种的33份种子,分别播种在相同的环境下,获得33个种群,测定了种群的16个形态性状,筛选出重复性好的9条ISSR引物,从33个种群中扩增出了109个位点。基于这些形态性状和ISSR位点信息,对33个种群先进行主成分分析,在此基础上再进行模糊均值聚类分析,探讨了它们的形态和遗传变化特点,及其与形态—遗传—地理背景三者之间的关系。主要结论如下:(1)33个种群可以鉴别出形态性状相对一致的4组,能够识别出西来稗(E.crus-galli var.zelayensis(Kunth)Farw.)、无芒稗(E.crus-galli var.mitis(Pursh)Peterm.)、细叶旱稗(E.crus-galli var.praticola Ohwi);(2)基于109个位点信息对33个种群进行聚类分析得到了6组,部分组与形态聚类分组有一定的对应性;(3)33个稗草种群的遗传分化受地理背景因素的影响(r=0.684,n=33,P<0.001);形态变异也有较明显的遗传背景因素(r=0.425,n=33,P<0.02)。在相对一致的稻田生境中,可能存在着形态上的趋同适应,使遗传上分化的组间在形态上又往往有交叉过渡,致使稗原变种(E.crus-galli var.crus-galli)、西来稗、无芒稗、短芒稗(E.crus-galli var.breviseta(D9ll)Podp.)在形态上难以区别;(4)基于遗传和形态数据分析,发现细叶旱稗无论在形态上,还是遗传上,均形成了明显的一组,推测与该种长期适应于干旱生境有关,建议将细叶旱稗提升为种的水平,并将其命名为Echinochloa praticola(Ohwi)Guo S L,Lu Y L,Yin L P&Zou M Y。展开更多
Echinochloa crus-galli is a major weed in rice fields in China,and quinclorac has been long used for its control.Over-reliance of quinclorac has resulted in quinclorac resistance in E.crus-galli.Two resistant(R)E.crus...Echinochloa crus-galli is a major weed in rice fields in China,and quinclorac has been long used for its control.Over-reliance of quinclorac has resulted in quinclorac resistance in E.crus-galli.Two resistant(R)E.crus-galli populations from Hunan,China were confirmed to be at least 78-fold more resistant to quinclorac than the susceptible(S)population.No difference in foliar uptake of 14C-labelled quinclorac was detected between the R and S plants.However,a higher level of 14C translocation and a lower level of quinclorac metabolism were found in the R plants.Basal and induced expression levels ofβ-cyanoalanine synthase(β-CAS)gene andβ-CAS activity were not significantly different between the R and S plants.However,the induction expression of 1-aminocyclopropane-1-carboxylic acid oxidase(ACO1)gene by quinclorac treatment was evident in the S plants but not in the R plants.Quinclorac resistance in the two resistant E.crus-galli populations was not likely to be related to foliar uptake,translocation or metabolism of quinclorac,nor to cyanide detoxification viaβ-CAS.Thus,target-site based quinclorac signal reception and transduction and regulation of the ethylene synthesis pathway should be the focus for further research.展开更多
为明确三唑磺草酮对直播稻田一年生禾本科杂草的防效、安全性及对常见后茬作物的影响,开展相关田间试验进行了研究。结果表明,6%三唑磺草酮可分散油悬浮剂对直播稻田稗草和千金子具有良好的效果。施药后40 d,103~135 g a.i./hm^(2)处理...为明确三唑磺草酮对直播稻田一年生禾本科杂草的防效、安全性及对常见后茬作物的影响,开展相关田间试验进行了研究。结果表明,6%三唑磺草酮可分散油悬浮剂对直播稻田稗草和千金子具有良好的效果。施药后40 d,103~135 g a.i./hm^(2)处理的总体株防效和鲜重防效分别达85.68%~94.69%和91.07%~96.95%,其中135 g a.i./hm^(2)处理的防效显著高于100 g/L氰氟草酯乳油105 g a.i./hm^(2)处理。6%三唑磺草酮可分散油悬浮剂在103~238 g a.i./hm^(2)剂量下对籼稻品种19香安全,与空白对照相比增产率达433%以上。在6%三唑磺草酮可分散油悬浮剂103.5~310.5 g a.i./hm^(2)剂量下,后茬作物菜心、花生和甜玉米的出苗率、株高、地上部生物量和产量均与空白对照无显著性差异。研究认为,6%三唑磺草酮可分散油悬浮剂可安全用于防除直播稻田常见一年生禾本科杂草,对后茬作物具有良好的安全性。展开更多
禾长蠕孢菌(Helminthosporium gramineum f. sp. echinochloae,HGE)是稗草生防潜力菌,为建立HGE的遗传转化体系,研究了菌龄、胞壁降解酶、稳渗剂等对其原生质体制备和再生的影响。结果表明,HGE菌原生质体制备的适宜条件为:26℃下采用1.0...禾长蠕孢菌(Helminthosporium gramineum f. sp. echinochloae,HGE)是稗草生防潜力菌,为建立HGE的遗传转化体系,研究了菌龄、胞壁降解酶、稳渗剂等对其原生质体制备和再生的影响。结果表明,HGE菌原生质体制备的适宜条件为:26℃下采用1.0%崩溃酶处理菌龄为6h的HGE菌丝体2h,0.7mol/LNaCl为稳渗剂。原生质体再生的适宜条件为:32℃下采用0.5%崩溃酶处理菌龄为16h的HGE菌丝体4h,0.7mol/LNaCl为稳渗剂,R1为高渗再生培养基。展开更多
基金supported by grants from the National Science and Technology Support Program of China(2012BAC01B05)
文摘Echinochloa crus-galli, one of the world＇s most serious weeds, influences seriously the yield and quality of cereal crop plant.It is well known that E.crus-galli grain is dormant, but its dormant type, as well as its dormancy release and germination in relation to galactomannan-hydrolysing enzyme activity were poorly understood.The cooperation of endo-β-mannanase（EC 3.2.1.78）, β-mannosidase（EC 3.2.1.25） and α-galactosidase（EC 3.2.1.22） can hydrolyze the cell walls rich in mannan-based polymers.In the present paper, the mature grains are used as experimental materials, we investigated the water uptake of grains, the effect of removing partial endosperm, after-ripening, stratification and phytohormone on grain germination, and the change in endo-β-mannanase, β-mannosidase and α-galactosidase activities of grains during after-ripening and germination.The results showed that the freshly-collected grains were water-permeable and had only phase I and II of water uptake, while the grains after-ripened for 150 d had an obvious phase III of water uptake.In alternating photoperiod, the germination of grains freshly-collected was zero at 10–35°C, and that of half grains was 11% at 20°C only.The grain germination was notably promoted by after-ripening and stratification, but not by gibberellic acid and 6-benzyladenine at 0.0001–1 mmol L–1.β-Mannosidase activity increased during 0 to 300 d of after-ripening and then decreased.The activity of endo-β-mannanase and α-galactosidase of grains decreased with after-ripening.During grain germination, endo-β-mannanase and β-mannosidase activities obviously increased, while α-galactosidase activity decreased.Our data showed that E.crus-galli grain was a deep physiological dormant, the dormancy release by after-ripening was related to an increasing β-mannosidase activity, and its germination was closely associated with an increasing endo-β-mannanase and β-mannosidase activity; which have provided new knowledge to decrease the harm of E.crus-galli on production of cereal crop plant.
基金the National Natural Science Foundation of China(30671381,30671381)Guangdong Provincial Natural Science Foundation of China(06300411)for the financial supports
文摘Exserohilum monoceras （Drechsler） Leonard and Suggs is a potential biocontrol agent for the control of Echinochloa species. This fungus causes leaf blight in Echinochloa species, but does not damage rice. Phytotoxicity of the fungal fermented broth was evaluated through the bioassay and the active ingredients were preliminarily isolated by using silica gel column chromatography （CC） in this study. The most active fraction 5-Ⅲ was obtained and analyzed by gas chromatography-mass spectrometry （GC-MS）. The results show that 5-Ⅲ consisted of many compounds, in which 36 compounds accounted for 94.24% of total peak area. Di-n-butyl phthalate （DBP） displayed the highest activity accounted for 9.24% of the total peak area, suggesting that DBP may be one of the main active compounds produced by E. monoceras.
文摘采集了浙江、福建、江苏、湖南、湖北、四川、重庆、黑龙江、河南9个省的稗(Echinochloa crus-galli(L.)P.Beauv.)及其变种的33份种子,分别播种在相同的环境下,获得33个种群,测定了种群的16个形态性状,筛选出重复性好的9条ISSR引物,从33个种群中扩增出了109个位点。基于这些形态性状和ISSR位点信息,对33个种群先进行主成分分析,在此基础上再进行模糊均值聚类分析,探讨了它们的形态和遗传变化特点,及其与形态—遗传—地理背景三者之间的关系。主要结论如下:(1)33个种群可以鉴别出形态性状相对一致的4组,能够识别出西来稗(E.crus-galli var.zelayensis(Kunth)Farw.)、无芒稗(E.crus-galli var.mitis(Pursh)Peterm.)、细叶旱稗(E.crus-galli var.praticola Ohwi);(2)基于109个位点信息对33个种群进行聚类分析得到了6组,部分组与形态聚类分组有一定的对应性;(3)33个稗草种群的遗传分化受地理背景因素的影响(r=0.684,n=33,P<0.001);形态变异也有较明显的遗传背景因素(r=0.425,n=33,P<0.02)。在相对一致的稻田生境中,可能存在着形态上的趋同适应,使遗传上分化的组间在形态上又往往有交叉过渡,致使稗原变种(E.crus-galli var.crus-galli)、西来稗、无芒稗、短芒稗(E.crus-galli var.breviseta(D9ll)Podp.)在形态上难以区别;(4)基于遗传和形态数据分析,发现细叶旱稗无论在形态上,还是遗传上,均形成了明显的一组,推测与该种长期适应于干旱生境有关,建议将细叶旱稗提升为种的水平,并将其命名为Echinochloa praticola(Ohwi)Guo S L,Lu Y L,Yin L P&Zou M Y。
基金financially supported by the National Natural Science Foundation of China (Grant Nos. 31701803 and 31772182)the Natural Science Foundation of Hunan Province (Grant No. 2017JJ3164) in China and the Australian Grains Research and Development Corporation (GRDC)
文摘Echinochloa crus-galli is a major weed in rice fields in China,and quinclorac has been long used for its control.Over-reliance of quinclorac has resulted in quinclorac resistance in E.crus-galli.Two resistant(R)E.crus-galli populations from Hunan,China were confirmed to be at least 78-fold more resistant to quinclorac than the susceptible(S)population.No difference in foliar uptake of 14C-labelled quinclorac was detected between the R and S plants.However,a higher level of 14C translocation and a lower level of quinclorac metabolism were found in the R plants.Basal and induced expression levels ofβ-cyanoalanine synthase(β-CAS)gene andβ-CAS activity were not significantly different between the R and S plants.However,the induction expression of 1-aminocyclopropane-1-carboxylic acid oxidase(ACO1)gene by quinclorac treatment was evident in the S plants but not in the R plants.Quinclorac resistance in the two resistant E.crus-galli populations was not likely to be related to foliar uptake,translocation or metabolism of quinclorac,nor to cyanide detoxification viaβ-CAS.Thus,target-site based quinclorac signal reception and transduction and regulation of the ethylene synthesis pathway should be the focus for further research.
文摘为明确三唑磺草酮对直播稻田一年生禾本科杂草的防效、安全性及对常见后茬作物的影响,开展相关田间试验进行了研究。结果表明,6%三唑磺草酮可分散油悬浮剂对直播稻田稗草和千金子具有良好的效果。施药后40 d,103~135 g a.i./hm^(2)处理的总体株防效和鲜重防效分别达85.68%~94.69%和91.07%~96.95%,其中135 g a.i./hm^(2)处理的防效显著高于100 g/L氰氟草酯乳油105 g a.i./hm^(2)处理。6%三唑磺草酮可分散油悬浮剂在103~238 g a.i./hm^(2)剂量下对籼稻品种19香安全,与空白对照相比增产率达433%以上。在6%三唑磺草酮可分散油悬浮剂103.5~310.5 g a.i./hm^(2)剂量下,后茬作物菜心、花生和甜玉米的出苗率、株高、地上部生物量和产量均与空白对照无显著性差异。研究认为,6%三唑磺草酮可分散油悬浮剂可安全用于防除直播稻田常见一年生禾本科杂草,对后茬作物具有良好的安全性。
文摘禾长蠕孢菌(Helminthosporium gramineum f. sp. echinochloae,HGE)是稗草生防潜力菌,为建立HGE的遗传转化体系,研究了菌龄、胞壁降解酶、稳渗剂等对其原生质体制备和再生的影响。结果表明,HGE菌原生质体制备的适宜条件为:26℃下采用1.0%崩溃酶处理菌龄为6h的HGE菌丝体2h,0.7mol/LNaCl为稳渗剂。原生质体再生的适宜条件为:32℃下采用0.5%崩溃酶处理菌龄为16h的HGE菌丝体4h,0.7mol/LNaCl为稳渗剂,R1为高渗再生培养基。
