A study was carried out to investigate changes in the soil plant-available P,the P nutrition and the growth of Pinus radiata seedlings grown in association with understory,broom（Cytisus scoparius L.） or ryegrass（Lo...A study was carried out to investigate changes in the soil plant-available P,the P nutrition and the growth of Pinus radiata seedlings grown in association with understory,broom（Cytisus scoparius L.） or ryegrass（Lolium multiflorum） on Orthic Allophanic Soil,following the application of three rates of triple superphosphate（TSP）（0,50,and 100 mg·kg^-1P） under a glasshouse condition.The application of P fertilizer enhanced P availability in the rhizospheric of radiata seedlings and the bulk soils in a P-deficient site.P availability in the rhizospheric soils of ryegrass and broom,grown in association with radiata,were also increased by the presence of radiata roots.P concentrations in new shoot needles,old shoot needles,stem and roots of radiata pine increased with increase rates of TSP application,but the effects of ryegrass and broom on P nutrition of radiata seedlings depended on the soil P status.In the absence of P fertilizer addition（control treatment）,P concentrations in new shoot needles,old shoot needles,stem,and roots of radiata grown in association with broom were higher than those with ryegrass,whereas,when P fertilizer was added（50 and 100 mg·kg^-1） the P concentration was lower.This is probably related to the growth of broom that may have removed much of the plant-available P in the soil as indicated by the consistently lower Bray-2 P concentration in the rhizosphere soil of radiata in association with broom than that in the rhizosphere soil of radiata in association with grass at the two high P rates.Furthermore,in the high P fertile soil（application rate of 100 mg·kg^-1）,the dry matter yield of radiata was lower when it was grown with broom than with ryegrass.This result suggests that in moderate to high P fertile soils,P.radiata seedlings grow better with ryegrass than with broom,because broom grows vigorously in high P fertile soil and competes with P.radiata for P and perhaps for other nutrients as well.展开更多
Pinus elliottii×P.caribaea is a widely planted commercial tree hybrid in South China.To investigate the potential of physiological parameters for clonal selection,cuttings of three clones(EH3,EH4 and EH5)and a co...Pinus elliottii×P.caribaea is a widely planted commercial tree hybrid in South China.To investigate the potential of physiological parameters for clonal selection,cuttings of three clones(EH3,EH4 and EH5)and a control were grown in phosphorus treated pots.Significant variations to phosphorous,photosystem II activity and polar metabolite abundance in needles were noted among clones.Clone EH5 was the most P-responsive and had maximum height growth.The highest maximum quantum yield of PSII in the dark(F_(v)/F_(m)),maximum quantum yield of PSII in the light(F_(v)'/F_(m)')and the actual PSII efficiency(Φ_(PSII))values were also found in EH5.A total of 64 polar metabolites were identified,21 were regulated by phosphorous,while 28 accumulated differentially among the three clones.There were few overlapping responsive metabolites to phosphorous fertilization.In EH5,the abundance of maltotriitol,neohesperidin and raffinose were highest,whereas galactinol and shikimic acid were lower compared with EH3 and EH4.The results reveal that physiological traits were genetically controlled and might be useful for selecting clones with high phosphorous utilization efficiency.展开更多
基金supported by Massey University and the Centre for Sustainable Forest Management at Forest Research Institute, New Zealand
文摘A study was carried out to investigate changes in the soil plant-available P,the P nutrition and the growth of Pinus radiata seedlings grown in association with understory,broom（Cytisus scoparius L.） or ryegrass（Lolium multiflorum） on Orthic Allophanic Soil,following the application of three rates of triple superphosphate（TSP）（0,50,and 100 mg·kg^-1P） under a glasshouse condition.The application of P fertilizer enhanced P availability in the rhizospheric of radiata seedlings and the bulk soils in a P-deficient site.P availability in the rhizospheric soils of ryegrass and broom,grown in association with radiata,were also increased by the presence of radiata roots.P concentrations in new shoot needles,old shoot needles,stem and roots of radiata pine increased with increase rates of TSP application,but the effects of ryegrass and broom on P nutrition of radiata seedlings depended on the soil P status.In the absence of P fertilizer addition（control treatment）,P concentrations in new shoot needles,old shoot needles,stem,and roots of radiata grown in association with broom were higher than those with ryegrass,whereas,when P fertilizer was added（50 and 100 mg·kg^-1） the P concentration was lower.This is probably related to the growth of broom that may have removed much of the plant-available P in the soil as indicated by the consistently lower Bray-2 P concentration in the rhizosphere soil of radiata in association with broom than that in the rhizosphere soil of radiata in association with grass at the two high P rates.Furthermore,in the high P fertile soil（application rate of 100 mg·kg^-1）,the dry matter yield of radiata was lower when it was grown with broom than with ryegrass.This result suggests that in moderate to high P fertile soils,P.radiata seedlings grow better with ryegrass than with broom,because broom grows vigorously in high P fertile soil and competes with P.radiata for P and perhaps for other nutrients as well.
基金funded by the Science and Technology Planning Project of Guangdong Province(2017B020205003)the Natural Science Foundation of Guangdong Province(2014A030313657)。
文摘Pinus elliottii×P.caribaea is a widely planted commercial tree hybrid in South China.To investigate the potential of physiological parameters for clonal selection,cuttings of three clones(EH3,EH4 and EH5)and a control were grown in phosphorus treated pots.Significant variations to phosphorous,photosystem II activity and polar metabolite abundance in needles were noted among clones.Clone EH5 was the most P-responsive and had maximum height growth.The highest maximum quantum yield of PSII in the dark(F_(v)/F_(m)),maximum quantum yield of PSII in the light(F_(v)'/F_(m)')and the actual PSII efficiency(Φ_(PSII))values were also found in EH5.A total of 64 polar metabolites were identified,21 were regulated by phosphorous,while 28 accumulated differentially among the three clones.There were few overlapping responsive metabolites to phosphorous fertilization.In EH5,the abundance of maltotriitol,neohesperidin and raffinose were highest,whereas galactinol and shikimic acid were lower compared with EH3 and EH4.The results reveal that physiological traits were genetically controlled and might be useful for selecting clones with high phosphorous utilization efficiency.
