Study On Negative Air Ion Concentration And Photosynthetic Characteristics Of18Species Of Ornamental Bamboos Such As Bambusa Vulgaris

Ornamental bamboos are all plants of the Gramineae Bambusoideae.There are more than70generasand more than1000species of Bamboos in the world.World bamboo geographical districts are Asia-Pacificbamboo district,American bamboo area,and Africa region.The Asia-Pacific bamboo district led by China isthe largest bamboo distribution.There are37generas and more than500species （including varieties）ofBamboos in China,accounting for more than50percent of the world bamboo generas and42percent of theworld bamboo species.Bamboos are widely seen in China.South to Hainan,north to Liaoning,east to Taiwai,west to Tibet.This article took18species of ornamental bamboos such as Bambusa vulgaris as research objects,tooktheir mechanism of physiological and ecological as research goal.They were studied with improving airquality and photosynthetic characteristics to explore diurnal variation of aero-anion concentration of18species of ornamental bamboos in different seasons and the relationship with environmental factors andexplore changes of photosynthetic characteristics and the relationship with environmental factors.Thisstudy provided a reference for other scientific research of the bamboos and selection basis for plantconfiguration.In this study,the conclusions were as follows:1、Diurnal variation curves of18species of ornamental bamboos showed with the bimodal,unimodal,U and W types in three seasons.In the spring mainly showed with bimodal and unimodal types.In the sum-mer,only Phyllostachys vivax ‘Aureocaulisand’ Phyllostachys edulis showed with bimodal type,othersshowed with a single peak,the U-shaped and W-type.In the fall,a single peak had the largest proportion andbimodal,U-and W-types had the same proportion.2、The highest frequency of the maximum period of negative air ion concentration were nearly10,12and16in three seasons with the values of61%,60%and60%.And the highest frequency of the maximumperiod of it were nearly14,16and18with the values of65%,54%and53%.It showed the maximum andminimum values of the negative air ion concentration had periods and different bamboo species of negativeair ion concentration in different seasons had different times of the maximum and minimum. 3、The maximum value of the negative air ion concentration of18species of ornamental bamboos wasdifferent in different seasons.In spring,the highest were Thyrsostachys oliveri,Chimonobambusa purpure,Bambusa ventricosa and Bambusa vulgaris.In summer were Bambusa ventricosa,Thyrsostachys oliveri,Phyllostachys prominens and Bambusa multiplex and in autumn were Bambusa vulgaris,Bambusaventricosa,Bambusa multiplex,Thyrsostachys oliveri and Phyllostachys prominens.Phyllostachys nigra hadthe the lowest in the spring,summer and autumn.4、Compared to an average daily concentration of negative ions in different seasons,most bamboospecies were significantly higher in summer and fall than that of in spring,in addition to the individualbamboo species.In spring,The highest was Chimonobambusa purpure,followed by Bambusa vulgaris andBambusa ventricosa,with values were462,451and435ions/cm³,in summer was Phyllostachys prominens,followed by Bambusa ventricosa and Phyllostachys aurea,with values were615,597and510ions/cm³,inautumn was Bambusa multiplex,followed by Bambusa vulgaris,Thyrsostachys oliveri,Bambusa ventricosaand Phyllostachys prominens,with values were636,623,556,489and510ions/cm³.The lowest average dailyconcentration of negative ions in summer and autumn was Phyllostachys aureosulcata f. spectabilis,withvalues were489and510ions/cm³.5、By correlation analyzing with SPSS18.0,the correlation between the negative air ion concentrationin18species of bamboos and temperature,humidity and light was not obvious,and no universality.only theindividual bamboo species in one season had positive correlation or negative correlation with one of thethree environmental factors,while the result was different in another season.Negative air ion concentrationof Thyrsostachys oliveri was negatively correlation with temperature,positively correlated with humidity insummer,but in autumn the result was opposite.In spring,That of Neosinocalamus affinis ‘Viridiflavus’ waspositively correlated with light intensity,so was Phyllostachys bambusoides var. castillonis with temperatu-re and light intensity.Sinobambusa tootsik in summer was negatively correlation with humidity,Bambusaeutuldoides var. viridi-vittata was highly positively correlated with light intensity.The correlation betweenthe negative air ion concentration and the external environment factors is not obvious,which reflected bam-boo species themselves were the mainly factors to the negative air ion concentration.6、By DPS,18species of bamboos were divided into three categories,according to the different averagedaily air concentration of negative ions in three seasons.The first category were Bambusa ventricosa,Bambusa multiplex,Bambusa vulgaris,Chimonobambusa purpure,Phyllostachys prominens and Thyrsosta-chys oliveri,which had the highest negative air ion concentration.The second were Bambusa eutuldoides var. viridi-vittata,Neosinocalamus affinis ‘Viridiflavus’,Phyllostachys bambusoides var. castillonis,Phyllostachys edulis,Phyllostachys aurea,phyllostachys viridis ‘Houzeauana’,Phyllostachys vivax‘Aureocaulis’,Dendrocalamus minor var. amoenus and Sinobambusa tootsik,which were in an intermediatelevel.The third were Phyllostachys aureosulcata ‘Aureocaulis’,Phyllostachys aureosulcata f. spectabilisand Phyllostachys nigra,which were the lowest.7、A=a(1-c₀e^{-b PAR/a})was the fitting curve equation of light response curve of18species ofBamboos.By calculating,light compensation point of them were between17.93and37.82μmol m^-2 s^-1,lightsaturation point were between663.10and1453.03μmol.m^-2.s^-1.It showed that light compensation point of18species were low,indicating bamboos adapt to low ligh with a certain degree of shade tolerance.Llightsaturation point changed in a big margin,reflecting part of the bamboo species were shade-loving plants,part of were light-loving plants.8、The apparent quantum yield （AQY） of18species of bamboos were between0.0169and0.0329.And AQY of Bambusa eutuldoides var. viridi-vittata,Chimonobambusa purpure,Phyllostachys edulis andBambusa vulgaris were bellow0.02μmol mol^-1.AQY of Bambusa eutuldoides var. viridi-vittata was minim-um and the maximum was phyllostachys viridis ‘Houzeauana’,followed by Phyllostachys prominens andNeosinocalamus affinis ‘Viridiflavus’,which rflected Bambusa eutuldoides var. viridi-vittata had the lowestlight use efficiency under low light,phyllostachys viridis ‘Houzeauana’ had the highest,followed by Phyllo-stachys prominens and Neosinocalamus affinis ‘Viridiflavus’ in the18tested bamboo species.9、By DPS,cluster analysis was analyzed according to the light compensation point,light saturation pointand the apparent quantum efficiency.The18species of bamboos were divided into three categories.The first category were Bambusa eutuldoides var. viridi-vittata,Dendrocalamus minor var. amoenus,Phyllostachys vivax ‘Aureocaulis’,Phyllostachys nigra and Bambusa vulgaris.The second were Phyllosta-chys prominens,Sinobambusa tootsik,Phyllostachys edulis,Chimonobambusa purpure,Phyllostachys aureo-sulcata f. spectabilis,Phyllostachys aurea,Bambusa ventricosa and phyllostachys viridis ‘Houzeauana’.Thethird were Phyllostachys bambusoides var. castillonis, Neosinocalamus affinis ‘Viridiflavus’,Thyrsostachysoliveri,Phyllostachys aureosulcata ‘Aureocaulis’ and Bambusa multiplex.The first category showed thehighest light compensation point,the lowest light saturation point and the apparent quantum efficiencywhich had narrow light adaptive environment,low light utilization under low light.It was the narrowestphotosynthetic range of application types which was suitable for growing in the forest edge and understory.The second showed a higher light compensation point,lower light saturation point and apparent quantum efficiency which had wide light adaptive environment,high light utilization under low light.It had widephotosynthetic range of application types which was suitable for growing in the upper canopy density,nothigh tree layer and the appropriate shade environment.The third showed the lowest light compensationpoint,the highest light saturation point and apparent quantum yield which had the widest light adaptiveenvironment,the highest light utilization under low light.It had the widest photosynthetic range ofapplication types which was suitable for growing in the forest edge,understory,as well as under directsunlight environment.