Effect Of Different Light Intensity On3Species Of Photinia Seedings Growth

In this paper,3species of Photinia seedlings:Photinia serrulata,Photini×fraseri 'Red Robin'and Photinia glabra 'Rubens' were chosed to study the response to growth and morphology,physiological and biochemical characteristics and photosynthetic fluorescence characteristicsunder different light intensity using shading treatment and natural habitat.Comprehensiveevaluation of3species by using subordinate function and phenotypic plasticity.The mainresearch results can be summarized in the following four points:(1)With the shade degree increased,3species of Photinia plants leaves red gradually faded,gradually deepened from yellowish green to green.Shading treatments had significant differenceon growth and biomass accumulation of Photinia serrulata seedlings.The effect of shadingtreatments on growth and biomass Photinia glabra 'Rubens' was evident only in the full lightconditions,and Photinia×fraseri 'Red Robin' significantly inhibited in the low-lightconditions.Therefore,in the commercial production,these3kinds of plants grown in the fieldmost suitable for light transmittance was25%.(2)With the reduction of the light intensity, the photosynthetic pigment content,the plasmamembrane relative permeability and the content of MDA of Photinia seedlings was graduallyincreasing,the content of anthocyanin and Chla/b was decreasing,and the content of solubleprotein changed in the curve for the V-shaped,while the opposite curve of the content of solublesugar.The POD of Photinia×fraseri 'Red Robin' and Photinia glabra 'Rubens' was reduced withthe reduction of light intensity.The conditions of light transmission rate of35%could weakenleaves of Photinia seedings turning green and extend the time of the red leaf.(3)Different light intensity conditions significantly affected the three kinds of Photinia plantPn,Ci,Tr,Gs and WUE diurnal variation.Three plants did not appear Pn decline at noon under theconditions of light transmission rate of15%and5%.Moderate shade to eliminate the plant'sphotosynthetic of midday depression have a positive effect.With the reduction of the lightintensity,AQY of3species of Photinia seedlings had different amplitude increases,and the LSPand LCP decreased.Shading treatments was also reduced in different degrees of Pmax and Rd.The Pmax and Rd of Photinia×fraseri 'Red Robin' and Photinia glabra 'Rubens' were higherthan that of Photinia serrulata.The diurnal variation of Fv′/Fm′,Yield and qP was expressed asV-shaped curve under the conditions of full light,the light transmission rate of35%and25%.Thediurnal variation of qN,NPQ and ETR showed a single peak curve under different lightintensity,with reduced light intensity showed a downward trend.(4)This shows that the normal growth of3kinds of plants in open areas,open forest andjungle conditions.However,it could foreground its appreciation effect under the conditions of the open forest,and could extend the viewing period.Analysis of Phenotypic suggested that most ofthe parameters of plasticity of Photinia×fraseri 'Red Robin' is greater than Photinia glabra'Rubens'and Photinia serrulata.This fully shows that Photinia×fraseri 'Red Robin' had strongerlight adaptation than the other.A comprehensive analysis of the sequence of shade-tolerance of3species of Photinia plantswas:Photinia×fraseri 'Red Robin'＞Photinia glabra 'Rubens'＞Photinia serrulata.