Biochar has been considered as a potential way to enhance acidophilous plant growth in alkaline soils.However,whether such enhancements are closely linked with biochar pyrolysis temperature and its improvements in rhi...Biochar has been considered as a potential way to enhance acidophilous plant growth in alkaline soils.However,whether such enhancements are closely linked with biochar pyrolysis temperature and its improvements in rhizospheric soil fertility and microbial activities remains largely unknown.We performed a pot experiment to investigate changes in azalea(Rhodo-dendron)morphology and physiology,as well as its rhizosphere soil chemical and biological properties in a slightly alkaline urban soil under the amendment of biochars that pyrolyzed at three temperatures(i.e.,350,550 and 700°C).Our results showed that the effects of biochars on plant growth and soil properties depended on pyrolysis temperature.In comparison with the non-amended control,350 and 550°C biochars showed significant promotions on the azalea growth in terms of photosynthetic characteristics,biomass,root morphology,and N and P uptake.Whereas,700°C biochar showed an inhibi-tion effect on them.350°C biochar decreased soil pH and increased soil available P and K contents and the activities ofα-glucosidase,N-β-glucosaminidase,phosphatase and sulfatase.In addition,350°C biochar significantly enhanced bacterial 16S rRNA and fungal 18S rRNA gene abundances in the rhizosphere soil of azalea and mycorrhizal infection.Correlation analysis indicated that soil pH,available nutrients and fungal abundance had positive associations with the enhanced plant growth parameters.Therefore,our findings suggest that biochar produced at low temperature could be a feasible strategy for enhancing acidophilous azalea growth and improving urban soil quality.展开更多
La3＋ and Ce3＋ have positive effects on plant growth and production. Although it is well known that rare earth elements promote cell growth. The biological effects of La^（3＋） and Ce^（3＋） on callus, shoot and ro...La3＋ and Ce3＋ have positive effects on plant growth and production. Although it is well known that rare earth elements promote cell growth. The biological effects of La^（3＋） and Ce^（3＋） on callus, shoot and root induction in tobacco are still unclear. The relationships among callus induction, rooting, enzyme activities and stomatal characteristics in tobacco are unknown. The objectives of this study were to identify the relationships between the induction of calluses, shoots, roots, stomata and enzyme activities. The induction percentages of calluses, buds, roots were recorded at 5,10,15, 20 and 25 days after La^（3＋） and Ce^（3＋） treatments. Peroxidase isoenzyme activity was determined by electrophoresis. The characteristics of the stomata were observed under an optical microscope. Our results show that low concentrations of Ce^（3＋）（〈15 mg/L） result in increases in the induction percentages of calluses,buds and roots, but La^（3＋）（〉5 mg/L） inhibits the induction of calluses, buds and roots. There are more peroxidase isoenzyme bands in Ce^（3＋） treatments than in La^（3＋） treatments. This is consistent with the induction percentages of calluses,buds and roots in Ce^（3＋） and La^（3＋） treatments. High enzyme activities may promote the induction of calluses, buds and roots. The stomata area and stomata number of leaves are significantly different between La^（3＋） treatments and Ce^（3＋） treatments. La^（3＋） improves the stomata area and number. Based on these results, we speculate that La^（3＋） may promote the development of the photosynthetic system. Ce^（3＋）may promote tobacco growth and rooting by improving enzyme activities.展开更多
基金The research was supported by the National Natural Science Foundation of China(41807100 and 41977083)Jiangsu Agricultural Science and Technology Innovation Fund(CX(19)3047)Jiangsu Provincial Forestry Development Special Fund[SuCaizihuan(2020)No.26].
文摘Biochar has been considered as a potential way to enhance acidophilous plant growth in alkaline soils.However,whether such enhancements are closely linked with biochar pyrolysis temperature and its improvements in rhizospheric soil fertility and microbial activities remains largely unknown.We performed a pot experiment to investigate changes in azalea(Rhodo-dendron)morphology and physiology,as well as its rhizosphere soil chemical and biological properties in a slightly alkaline urban soil under the amendment of biochars that pyrolyzed at three temperatures(i.e.,350,550 and 700°C).Our results showed that the effects of biochars on plant growth and soil properties depended on pyrolysis temperature.In comparison with the non-amended control,350 and 550°C biochars showed significant promotions on the azalea growth in terms of photosynthetic characteristics,biomass,root morphology,and N and P uptake.Whereas,700°C biochar showed an inhibi-tion effect on them.350°C biochar decreased soil pH and increased soil available P and K contents and the activities ofα-glucosidase,N-β-glucosaminidase,phosphatase and sulfatase.In addition,350°C biochar significantly enhanced bacterial 16S rRNA and fungal 18S rRNA gene abundances in the rhizosphere soil of azalea and mycorrhizal infection.Correlation analysis indicated that soil pH,available nutrients and fungal abundance had positive associations with the enhanced plant growth parameters.Therefore,our findings suggest that biochar produced at low temperature could be a feasible strategy for enhancing acidophilous azalea growth and improving urban soil quality.
基金Project supported by the Provincial Key Laboratory of Agrobiology(49114042016Z06)Jiangsu Academy of Agricultural Sciences and the Natural Science Foundation of Jiangsu Province of China(BK20161375)
文摘La3＋ and Ce3＋ have positive effects on plant growth and production. Although it is well known that rare earth elements promote cell growth. The biological effects of La^（3＋） and Ce^（3＋） on callus, shoot and root induction in tobacco are still unclear. The relationships among callus induction, rooting, enzyme activities and stomatal characteristics in tobacco are unknown. The objectives of this study were to identify the relationships between the induction of calluses, shoots, roots, stomata and enzyme activities. The induction percentages of calluses, buds, roots were recorded at 5,10,15, 20 and 25 days after La^（3＋） and Ce^（3＋） treatments. Peroxidase isoenzyme activity was determined by electrophoresis. The characteristics of the stomata were observed under an optical microscope. Our results show that low concentrations of Ce^（3＋）（〈15 mg/L） result in increases in the induction percentages of calluses,buds and roots, but La^（3＋）（〉5 mg/L） inhibits the induction of calluses, buds and roots. There are more peroxidase isoenzyme bands in Ce^（3＋） treatments than in La^（3＋） treatments. This is consistent with the induction percentages of calluses,buds and roots in Ce^（3＋） and La^（3＋） treatments. High enzyme activities may promote the induction of calluses, buds and roots. The stomata area and stomata number of leaves are significantly different between La^（3＋） treatments and Ce^（3＋） treatments. La^（3＋） improves the stomata area and number. Based on these results, we speculate that La^（3＋） may promote the development of the photosynthetic system. Ce^（3＋）may promote tobacco growth and rooting by improving enzyme activities.
