Cr,Cu Stress On The Influence Of Two Hosta Growth And Physiological Characteristics

This article based on Hosta of Liliaceae,Hosta×Hybrida ‘So Sweet’ and Hostaventricosa points of single seedlings as test materials, controlled by pot experiment, researchon heavy metal Cr (0(CK), Cr20, Cr200, Cr400), Cu (0(CK), Cu40, Cu200, Cu400)single stress and Cr, Cu (0, Cr20+Cu40, Cr200+Cu200, Cr400+Cu400) under complexstress on the growth of the two Hosta, accumulation ability, biological character and thechanging rule of the photosynthetic characteristics, physiological and biochemical indexessuch as, for different levels of heavy metal pollution area screening economical perennial rootflowers and plants for vegetation restoration to provide theoretical basis and technicalsupport.The results of the study are as follows:1,In heavy metal Cr (Cr20-Cr200), Cu (Cu40-Cu200) single and Cr, Cu (Cr20+Cu40Cr200+Cu200) composite processing, two kinds of different impact on the growth of Hosta,show the leaflets of tip ministries appear back green, yellow, foliage appear dead spot,flowering scapes showed easy lodging.With the increase of the concentration of heavy metalCr (Cr400), Cu (Cu400) single and Cr, Cu (Cr400+Cu400) composite processing under itsgrowth characteristics influence gradually increased, the plant small, leaf blade sparsely, olderleaves back green, wilting, new leaves grow slowly, some new leaves without exhibition leafnecrosis.Biomass was also inhibit in different degrees.2,2kinds of Hosta to the absorption and accumulation of Cr, Cu, mainly in theunderground part, its aboveground content is relatively small, the root of the heavy metals Cr,Cu fixed ability is stronger, the processing of Hosta×Hybrida ‘So Sweet’ roots of Cr, Cucontent were higher than Hosta ventricosa, the maximum content of Cr were157.15mg·kg-1and141.35mg·kg-1, maximum Cu content were139.58mg·kg-1,118.96mg·kg-1, Cr, Cucomposite stress Hosta×Hybrida ‘So Sweet’ underground part containing Cr a maximum of76.84mg·kg-1, containing Cu a maximum of127.64mg·kg-1; Hosta ventricosa undergroundpart containing Cr a maximum of70.27mg·kg-1, containing Cu a maximum of120.43mg·kg-1,by comparison, the composite stress Hosta×Hybrida ‘So Sweet’ higher than Hostaventricosa Cr content than6.56mg·kg-1, Cu content higher than7.21mg·kg-1.Two Hosta accumulation is decided by the biomass and content, under the stress of highconcentrations of Cr, Cu,2kinds of Hosta the whole single plant of heavy metalaccumulation in Hosta ventricosa is the highest. Cr400+Cu400composite stress processing, the accumulation of other order: Hosta*Hybrida ‘So Sweet’ Cr400> Hosta*Hybrida ‘SoSweet’ Cr400+Cu400> Hosta ventricosa Cr400> Hosta*Hybrida ‘So Sweet’ Cu400> Hostaventricosa Cu400.In the soil polluted by heavy metals Cr, Cu stress environment, absorbingability and accumulation from two Hosta is found, Hosta*Hybrida ‘So Sweet’ absorption andaccumulation of heavy metals Cr, Cu ability higher than Hosta ventricosa.3, In the single Cr and Cr, Cu composite processing, decreased with the increase of theconcentration of2kinds of Hosta chlorophyll a and chlorophyll b content showed a trend ofrise after the fall of the first, in the single processing, Cu decreased with the increase of theconcentration of2kinds of Hosta chlorophyll a and chlorophyll b content gradually reducethe trend.Of Cr, Cu, single stress two h. chlorophyll a/b content gradually reduce with theincrease of concentration of heavy metal Cr, Cu, Cr, Cu effect on chlorophyll a is greater thanchlorophyll b;But under the stress of Cr, Cu composite, two kinds of Hosta chlorophyll a/bcontent increased with the increase of concentration of heavy metal Cr, Cu, the processing oftwo kinds of Hosta chlorophyll b is greater than the influence of chlorophyll a.4, In the low concentration of heavy metal Cr and Cr, Cu under complex stress, twokinds of Hosta.Pmaxhas a certain degree of rise, but with increasing concentration,2kinds ofHosta Pmaxthan also decreases with the control. Hosta×Hybrida ‘So Sweet’ to the strong andweak light utilization ability is stronger, under the stress of heavy metals Cr, Cu, maintain arelatively high level of maximum net photosynthetic rate and apparent quantum efficiency,have higher tolerance to heavy metal.Two host photosynthetic parameters research shows that:the daily change of2kinds of Hosta "bimodal" type curve, the apparent photosynthetic "lunchbreak" phenomenon;Net photosynthetic rate, transpiration rate and stomatal conductance werepositively correlated, and negatively correlated with intercellular CO2mole fraction.Highlevels of stress when two Hosta of photosynthesis is restrained, net photosynthetic rate (Pn),stomatal conductance (Gs) and transpiration rate (Tr) with the increase of the concentration ofCr, Cu, stress and declining, intercellular CO2concentration (Ci) in high concentration higherthan the control group, under heavy metal stress are the major factors that limitphotosynthesis stomatal limitation.5, Under different concentrations of Cr, Cu,2kinds of SOD and POD enzyme appeareddifferent degree of Hosta peroxide oxidation inhibition and toxic.SOD and POD enzymeactivity with concentration increasing processing have been increased after the change trendof lower, that under the stress of high concentrations of Cr, Cu, two Hosta of SOD and PODenzyme self-protection ability has certain limits, reactive oxygen species and the balance ofantioxidant system was damaged, the activity of SOD and POD decreased.MDA content inplant membranous peroxide reaction, protect the plant itself under the condition of equilibrium in adversity.Two kinds of Hosta×Hybrida ‘So Sweet’ under the effect of heavymetals Cr, Cu increased with the concentration.From two Hosta has the change of SOD andPOD enzyme activity and MDA content, antioxidant enzymes Hosta×Hybrida ‘So Sweet’:protect ability stronger than the Hosta ventricosa, membrane lipid level is lower than theHosta ventricosa.