Abstract: To investigate the effect of plant growth regulators (PGRs)on the yield and phytohormone in sweet potato,the experiments were conducted with the spraying of PGRs at the beginning of enlargement stage in Jinan experimental base of SAAS.The effects of PGRs on the yield,dry matter distribution,photosynthesis and the phytohormone in root and leaf were investigated in three types (exuberant,general and feeblish of over ground part) sweet potato under field conditions.The results showed that the PGRs increased the root yield of sweet potato,enhanced the transfer of assimilation to the root.The mixture of CCC and DA-6 increased the photosynthetic rate of Xushu 18 and the effect of S3307 on the photosynthesis of 3 varieties was not significant compared with the contrast,and there was no significant relationship between the effect of PGRs on the photosynthesis and root yield.The treatment of S3307 decreased the concentration of leaf IAA in 3 sweet potato varieties,and decreased leaf ZR and GA₃ content in middle expansion period of Jishu 18,and decreased the leaf ZR and ABA content in later expansion period of Xushu 18,and the treatment of S3307 increased the leaf ABA content in middle and later expansion period and the root IAA content in front and middle expansion period of Jishu 18 and Xushu 18,and the IAA content in root of Shangshu 0110 was improved by S3307 during the expansion period.The mixture of CCC and DA-6 decreased the leaf IAA content in middle and root and leaf ZR content in later expansion period of Jishu 18,and decreased the leaf IAA,ZR,ABA and root ZR content in fronter expansion period of Xushu 18,and decreased the leaf GA₃ in froner stage and the ZR content in later expansion stage.The mixture of CCC and DA-6 in increased the root ABA,GA₃ and leaf ZR content in fronter stage and leaf ABA content in middle stage and root IAA content during the expansion stage of Jishu 18,and increased the leaf ZR content in froner stage and root GA₃ and ZR,leaf IAA and ABA content in middle stage and root IAA content in later expansion period of Xushu 18,and increased the root ZR and ABA in the whole period and leaf ZR content in middle stage and leaf GA₃ content in later expansion stage of Shangshu 0110.The treatment of PGRs changed the trend of phytohormone content of sweet potato on a certain extent,and promoted the transfer of assimilation from leaf and stem to the root,increasing the yield of tuberous root.The effect of PGRs on the photosynthesis varied with variety type,which was not the main effect of tuberous root yield.

Key words: Sweet potato, PGRs, Yield, Photosynthesis, Phytohormone

CLC Number: 

• S531.01