Phosphorus is an important element for larch (\%Larix gmelinii\% Rupr.)root development.P-availability in rhizosphere is close with root exudates or excretions,e.g.,organic acid exudation,proton excretion.These materi...Phosphorus is an important element for larch (\%Larix gmelinii\% Rupr.)root development.P-availability in rhizosphere is close with root exudates or excretions,e.g.,organic acid exudation,proton excretion.These materials from roots will affect pH value of rhizosphere.The aim of this paper were to study on pH changes at different P-stress conditions,and to test on the relation between available P and pH in rhizosphere.This work was carried out under pot experiment and field soil smaple analysis.Larch seedlings,1 and 2-year-old,were planted into sand pots.Nutrient solution with different P contents (0,0.035,0.071 and 0.142g·L -1 respectively) were supplied everyday.There were 2 replicates for 1-year-old seedlings,5 replicates for 2-year-old seedlings at ecch P-level treatment.After 1-year-old seedlings growing for 40 days and 2-year-old seedlings growing for 90 days,seedlings were taken out and used to visualize acidification by means of an agar plate technique.The result showed that pH of rhizosphere decreased from 6.40 to 4.73～4.84 in 1-year-old seedlings and to 5.30～5.50 in 2-year-old after 36h incubation.Average pH decreased were 1.56～1.67 for 1-year-old seedlings,and 0.90～1.10 for 2-year-old seedlings.There was not significant,for pH variations in rhizosphere,among four kind treatments.The pH change was not affected by P-level.The result of soil sample analysis,from 12-year-old,21-year-old,and 40-year-old pure larch stands respectively,indicated that the pH changes in rhizosphere is 0.11,0.04,and 0.09,respectively,lower than that in the non-rhizosphere,acidification is not significant,While the available P in the rhizosphere is 18.1%,86.5% and 23.4%,higher than that in the non-rhizosphere in three stands.The correlation between pH variations and available P was not remarkable at this analysis.This means that there was no relationship between the available P and pH change of rhizosphere in larch root system.展开更多
采用反相高效液相色谱法对不同种质(北京、东北),不同生长年限关黄柏中有效成分(小檗碱、巴马汀、药根碱)含量的变化规律进行研究。为科学地确定关黄柏采收期,保护关黄柏资源提供依据。高效液相色谱法,色谱柱:Alltim a HP C1(8250mm...采用反相高效液相色谱法对不同种质(北京、东北),不同生长年限关黄柏中有效成分(小檗碱、巴马汀、药根碱)含量的变化规律进行研究。为科学地确定关黄柏采收期,保护关黄柏资源提供依据。高效液相色谱法,色谱柱:Alltim a HP C1(8250mm×4.6mm,5μm),流动相:乙腈-0.1%磷酸水溶液(40:60,含种0.1质%(的吉十林二通烷化基)磺9年酸生钠以),上流的速关:1黄.0柏m中L/m小in檗;柱碱温含:量25可℃达,检到测中波国长药:典34规5定nm的。含北量京要种求质。2不年同生种以质上,、不东北同生长年限的关黄柏生物碱含量具有差异性,且变化趋势不同。展开更多
文摘Phosphorus is an important element for larch (\%Larix gmelinii\% Rupr.)root development.P-availability in rhizosphere is close with root exudates or excretions,e.g.,organic acid exudation,proton excretion.These materials from roots will affect pH value of rhizosphere.The aim of this paper were to study on pH changes at different P-stress conditions,and to test on the relation between available P and pH in rhizosphere.This work was carried out under pot experiment and field soil smaple analysis.Larch seedlings,1 and 2-year-old,were planted into sand pots.Nutrient solution with different P contents (0,0.035,0.071 and 0.142g·L -1 respectively) were supplied everyday.There were 2 replicates for 1-year-old seedlings,5 replicates for 2-year-old seedlings at ecch P-level treatment.After 1-year-old seedlings growing for 40 days and 2-year-old seedlings growing for 90 days,seedlings were taken out and used to visualize acidification by means of an agar plate technique.The result showed that pH of rhizosphere decreased from 6.40 to 4.73～4.84 in 1-year-old seedlings and to 5.30～5.50 in 2-year-old after 36h incubation.Average pH decreased were 1.56～1.67 for 1-year-old seedlings,and 0.90～1.10 for 2-year-old seedlings.There was not significant,for pH variations in rhizosphere,among four kind treatments.The pH change was not affected by P-level.The result of soil sample analysis,from 12-year-old,21-year-old,and 40-year-old pure larch stands respectively,indicated that the pH changes in rhizosphere is 0.11,0.04,and 0.09,respectively,lower than that in the non-rhizosphere,acidification is not significant,While the available P in the rhizosphere is 18.1%,86.5% and 23.4%,higher than that in the non-rhizosphere in three stands.The correlation between pH variations and available P was not remarkable at this analysis.This means that there was no relationship between the available P and pH change of rhizosphere in larch root system.
文摘采用反相高效液相色谱法对不同种质(北京、东北),不同生长年限关黄柏中有效成分(小檗碱、巴马汀、药根碱)含量的变化规律进行研究。为科学地确定关黄柏采收期,保护关黄柏资源提供依据。高效液相色谱法,色谱柱:Alltim a HP C1(8250mm×4.6mm,5μm),流动相:乙腈-0.1%磷酸水溶液(40:60,含种0.1质%(的吉十林二通烷化基)磺9年酸生钠以),上流的速关:1黄.0柏m中L/m小in檗;柱碱温含:量25可℃达,检到测中波国长药:典34规5定nm的。含北量京要种求质。2不年同生种以质上,、不东北同生长年限的关黄柏生物碱含量具有差异性,且变化趋势不同。
