Effects Of Foliar Feeding Of Selenium On Fruit Qualily, Accumulation OfCadmium, Lead And Mercury And Physiological Indexes Of Leaves In Sweet Persimmon And Grape

‘Youhou’,‘Okitsu20’ and ‘Jiro’ sweet persimmon were sprayedSe-fertilizer on leaves at the Na₂SeO₃concentrations of0,50,100,150and200mg·L-1.‘Flame seedless’,‘black seedless’,‘Giant rose’,‘Victoria’,‘Centennialseedless’,‘Moldova’ and ‘Ruby seedless’ grape were sprayed Se-fertilizer on leavesat the Na₂SeO₃concentrations of0and50mg·L-1. Heavy metal cadmium（Cd）, lead（Pb）and mercury （Hg） accumulation, fruits quality and photosynthesis affected byspraying Se-fertilizer to persimmon leaves. The interactive effects between seleniumand heavy metal were investigated. The study may provide the theory basis forincrease the persimmon quality with Se-fertilizer on leaves. The research results showthat spraying Se-fertilizer on leaves is a preferable method for supplementingselenium to persimmon and grape and the deposition of Cd, Pb and Hg in thepersimmon and grape leaves and fruits were refrained. The Na₂SeO₃concentration of150mg·L-1was the optimum treatment and selenium content in leaf and fruits wentup with the Se content in spraying concentration. The content of Cd, Pb and Hg in theleaves and fruits decreased with increasing selenium concentration under differentselenium treatment from0to150mg·L-1, and the soluble sugar, titratable acid, Vc andsoluble solid in the fruits were improved, but when increased to the highestconcentration, the trend was opposite. Se-fertilizer has the most obvious inhibition tothe deposition of Cd and Hg for ‘Okitsu20’ while Pb for ‘Jiro’. Furthermore,compared with ‘Youhou’ and ‘Jiro’,‘Okitsu20’ had the highest sensitivity to externalselenium and had a better performance. The results also indicated that50mg·L-1Na₂SeO₃was considered the optimum concentration for foliar feeding of Se on grapetrees. Cd, Pb and Hg accumulation could significantly decreased on this concentration.Of the seven cultivars used in this study,‘Flame seedless’ had the best fruit quality;The heave metals in ‘black seedless’,‘Giant rose’,‘Victoria’ decreased more than other cultivars. In the sweet persimmon and grape leaves, the activity of SOD andPOD significantly increased, while the soluble sugar content, soluble protein content,chlorophy Ⅱcontent, proline content and MDA content decreased under the optimumconcentration. This can keep the tree have the high ability of anti-aging andanti-oxidation.According to measure the leaf photosynthetic of ‘Youhou’ and ‘Giantrose’ which were sprayed different Na₂SeO₃concentration on leaves, netphotosynthetic rate, transpiration rate and stomatal conductance were increased, andintercellular C_O2concentration was decreased. The diurnal courses of Pn, Tr and Gswere double-peaked curves with the highest value reached at10:00and the secondvalue occurred at14:30of ‘Youhou’, the peak of ‘Giant rose’ was respectively at10:00and16:00, but the sustained time of midday depression of photosynthesis wasdifferent.