One bacteria endophyte were isolated from the root nodules of Podocarpus macrophyllus(Thunb.)D.Don.The bacteria has the ordinary characteristics of Rhizobium of leguminous plants after indentification.It made nodulati...One bacteria endophyte were isolated from the root nodules of Podocarpus macrophyllus(Thunb.)D.Don.The bacteria has the ordinary characteristics of Rhizobium of leguminous plants after indentification.It made nodulation on its host after inoculation strains.So did on Podocarpus nagi(Thunb.)zoll.et Mor.ex Zoll. seedling which is of the same family and genus with Podocarpus macrophyllus(Thunb.)D.Don.Both strain and host seeding have C 2H 4 reduction activity.But it can not made nodulation on 11 kind of offering tests of leguminous plants after inoculation strains.According to its characteristics the bacteria thus appears to be a member of a disinct Rhizobium lineage.Its phylogenetic relationship position remain to be research.展开更多
The number, weight, volume, density, shape and distribution of the root nodules were investigated in three different Casuarina equisetifolia plantations in Haikou, Hainan Province. The results showed that the biomass ...The number, weight, volume, density, shape and distribution of the root nodules were investigated in three different Casuarina equisetifolia plantations in Haikou, Hainan Province. The results showed that the biomass of root nodules in the sandy tidal soil was biggest, much bigger than that in sandy wind blown soil and sandy alluvial soil. The nitrogen content in soil was the most important factor that affected the biomass of the nodules. The other physical and chemical properties of the different soil types also affected the number, volume, shape and distribution of the nodules in soils.展开更多
为研究种植模式和施氮量对大豆土壤通气环境及结瘤固氮的影响,本研究采用二因素裂区试验设计,主区为种植模式:大豆单作(SS)、玉米/大豆带状套作(MS),副区为不同施氮量:不施氮(NN:0 kg hm^(–2))、减量施氮(RN:45 kg hm^(–2))和常量施氮...为研究种植模式和施氮量对大豆土壤通气环境及结瘤固氮的影响,本研究采用二因素裂区试验设计,主区为种植模式:大豆单作(SS)、玉米/大豆带状套作(MS),副区为不同施氮量:不施氮(NN:0 kg hm^(–2))、减量施氮(RN:45 kg hm^(–2))和常量施氮(CN:60 kg hm^(–2)),监测了大豆生育期内土壤的O_(2)含量和土壤呼吸速率的动态变化规律,分析了各处理的土壤水稳性团聚体、容重和孔隙度差异,探讨了大豆生育期内结瘤量、固氮能力的变化特征。2年数据结果表明,与单作大豆相比,带状套作大豆可提高土壤O_(2)含量、>2 mm粒径团聚体的百分含量、显著增加土壤孔隙度、显著增强后期土壤呼吸的速率,显著降低<1 mm粒径团聚体百分含量与土壤孔隙度;R5期根瘤干重差异不显著,但结瘤数量显著增加39.9%,固氮酶活性与固氮潜力也在此时显著高于单作大豆。各施氮量间,土壤O_(2)含量、0.25~1.00 mm粒径的百分含量、带状套作大豆的土壤呼吸速率以RN处理最高,施氮能降低<0.25 mm粒径的水稳性团聚体的百分含量、土壤容重,施氮显著抑制单作大豆前期的结瘤量、固氮酶活性和固氮潜力,至R5期氮肥的抑制作用有所缓解,减量施氮可提升带状套作大豆后期的结瘤量,显著增强大豆生育期内的固氮酶活性和固氮潜力。带状套作大豆配施减量施氮会促进大团聚体的形成,增加土壤的孔隙度,改善大豆土壤的通气环境状况,保持了较高的土壤O_(2)含量,促进土壤呼吸,有利于大豆后期结瘤固氮。展开更多
文摘One bacteria endophyte were isolated from the root nodules of Podocarpus macrophyllus(Thunb.)D.Don.The bacteria has the ordinary characteristics of Rhizobium of leguminous plants after indentification.It made nodulation on its host after inoculation strains.So did on Podocarpus nagi(Thunb.)zoll.et Mor.ex Zoll. seedling which is of the same family and genus with Podocarpus macrophyllus(Thunb.)D.Don.Both strain and host seeding have C 2H 4 reduction activity.But it can not made nodulation on 11 kind of offering tests of leguminous plants after inoculation strains.According to its characteristics the bacteria thus appears to be a member of a disinct Rhizobium lineage.Its phylogenetic relationship position remain to be research.
文摘The number, weight, volume, density, shape and distribution of the root nodules were investigated in three different Casuarina equisetifolia plantations in Haikou, Hainan Province. The results showed that the biomass of root nodules in the sandy tidal soil was biggest, much bigger than that in sandy wind blown soil and sandy alluvial soil. The nitrogen content in soil was the most important factor that affected the biomass of the nodules. The other physical and chemical properties of the different soil types also affected the number, volume, shape and distribution of the nodules in soils.
文摘为研究种植模式和施氮量对大豆土壤通气环境及结瘤固氮的影响,本研究采用二因素裂区试验设计,主区为种植模式:大豆单作(SS)、玉米/大豆带状套作(MS),副区为不同施氮量:不施氮(NN:0 kg hm^(–2))、减量施氮(RN:45 kg hm^(–2))和常量施氮(CN:60 kg hm^(–2)),监测了大豆生育期内土壤的O_(2)含量和土壤呼吸速率的动态变化规律,分析了各处理的土壤水稳性团聚体、容重和孔隙度差异,探讨了大豆生育期内结瘤量、固氮能力的变化特征。2年数据结果表明,与单作大豆相比,带状套作大豆可提高土壤O_(2)含量、>2 mm粒径团聚体的百分含量、显著增加土壤孔隙度、显著增强后期土壤呼吸的速率,显著降低<1 mm粒径团聚体百分含量与土壤孔隙度;R5期根瘤干重差异不显著,但结瘤数量显著增加39.9%,固氮酶活性与固氮潜力也在此时显著高于单作大豆。各施氮量间,土壤O_(2)含量、0.25~1.00 mm粒径的百分含量、带状套作大豆的土壤呼吸速率以RN处理最高,施氮能降低<0.25 mm粒径的水稳性团聚体的百分含量、土壤容重,施氮显著抑制单作大豆前期的结瘤量、固氮酶活性和固氮潜力,至R5期氮肥的抑制作用有所缓解,减量施氮可提升带状套作大豆后期的结瘤量,显著增强大豆生育期内的固氮酶活性和固氮潜力。带状套作大豆配施减量施氮会促进大团聚体的形成,增加土壤的孔隙度,改善大豆土壤的通气环境状况,保持了较高的土壤O_(2)含量,促进土壤呼吸,有利于大豆后期结瘤固氮。
