Effects of foliar spraying selenium solution on selenium content,yield and nutrition quality of pumpkin fruit
In order to provide the best selenium enrichment scheme and theoretical basis for the safe production of seleni-um rich pumpkins,the optimal spraying period and concentration were determined by studying the effects of foliar spray-ing selenium solution at different stages on the selenium content,yield,quality and mineral element content of the pump-kin fruits.In this paper,Olive Beibei No.2 was used as the test material and the sodium selenite as the selenium source.Three spraying periods(vines stage+female flowering stage,vines stage+fruit expansion stage,female flowering stage+fruit expansion stage)and four concentration levels(0,207,321 and 723 μmol·L-1)were set up in the experiment of foli-ar spraying selenium solution.The results showed that after spraying selenium fertilizer,the selenium content of pumpkin fruits compared with CK increased significantly with the increase of selenium solution concentration and the seleniums in pumpkin fruits were all organic.The selenium contents of pumpkin fruits which treated with the same concentration were"female flowering stage+fruit expansion stage">"vines stage+fruit expansion stage">"vines stage+female flowering stage".It was found that spraying selenium solution on pumpkins leaves not only could improve the quality of individual fruits,but also could increase the content of carotene,vitamin C,starch,soluble protein,soluble solids and soluble sugar in pumpkin fruits at different degrees.But there was no significant impact on amino acid content after spraying selenium solution.The impact of spraying selenium solution on the mineral element content of pumpkin fruit manifested in the in-hibitory effect on the enrichment of Pb and Cd and the significant increase of the content of Fe and K.The content of Zn and Cu is significantly reduced after applying an appropriate concentration of selenium solution,but the Na,Mg,and Ca content had no change.By regression equations,the selenium content of pumpkin fruits met the selenium enrichment stan-dard after spraying sodium selenite solution at 1-197 μmol·L-1 once in the female flowering stage and fruit expansion stage respectively.
PumpkinSeleniumYieldNutrition qualityMineral element