%0 Journal Article %A DUAN Wenxue %A ZHANG Haiyan %A XIE Beitao %A WANG Qingmei %A WANG Baoqing %A ZHANG Liming %T Influence of Application Methods of Polypeptidase Activity Promoter on the Dry Matter Accumulation and Distribution, Root Yield, and Quality of Raw-edible Sweet Potato %D 2019 %R 10.11869/j.issn.100-8551.2019.05.1016 %J Journal of Nuclear Agricultural Sciences %P 1016-1023 %V 33 %N 5 %X In order to investigate the regulating effect of polypeptidase activity promoter on the yield and quality of the raw-edible sweet potato, a field experiment was conducted by using the raw-edible sweet potato varieties Longshu 9 and Sushu 8. Each cultivar received one of the following treatments: CK-no application of the polypeptidase activity promoter throughout the entire growth period; P1-root dipping prior to planting and foliar spraying at 40 days after planting with the polypeptidase activity promoter; P2-root irrigation when planting and foliar spraying at 40 days after planting with the polypeptidase activity promoter. The effects of polypeptidase activity promoter on the dry matter accumulation and distribution, root yield, and quality were estimated. The results show that P1- and P2-treated plants exhibited considerably higher leaf SPS activity, sucrose content during mid- and late-growth stages, and plant and root dry weights at harvest than CK-treated plants. At harvest, distribution portion of dry matter in the lateral branches and roots of Longshu 9 plants were not significantly different under different treatments. Distribution portion of dry matter in nether leaves of main stem and nether stem of main stem in Longshu 9 P1- and P2-treated plants was significant lower than that in CK-treated plants. For cultivar Sushu 8, distribution portion of dry matter in nether leaves of main stem, nether stem of main stem, lateral branches and growth point of lateral branches in P2-treated plants was significant lower than that in CK- and P1-treated plants. Compared with CK- and P1-treated plants, the distribution portion of dry matter in tuberous roots of P2-treated plants was significantly increased by 8.98% and 6.23% for cultivar Sushu 8, respectively. At harvest, the soluble sugar content of P2-treated plants for Longshu 9 showed no significant difference with that in P1-treated plants and was significantly decreased by 5.22% compared with CK-treated plants. The starch content of P2-treated plants for Longshu 9 was significantly increased by 18.76% and 9.23% compared with CK-and P1-treated plants. The dry matter contents of tuberous roots of P2-treated plants for Longshu 9 showed no significant difference with that in P1-treated plants. Compared with CK treated plants, the dry matter contents of tuberous roots of P1- and P2-treated plants for Longshu 9 significantly increased by 4.56% and 5.71%, respectively. The soluble sugar content of tuberous roots for Sushu 8 showed no significant difference among different treatments whereas the starch content and dry matter contents of tuberous roots in P2-treated plants showed no significant difference with that in P1-treated plants. Compared with CK-treated plants, the starch content and dry matter content of tuberous roots in P2-treated plants were significantly increased by 6.13% and 4.51%, respectively. Compared with CK- and P1-treated plants, the root yield of P2-treated plants were significantly increased by 30.46% and 14.42% for cultivar Longshu 9 and by 27.72% and 11.69% for cultivar Sushu 8, respectively. In conclusion, application of polypeptidase activity promoter improved the root yield and starch content in tuberous roots of raw-edible cultivars. P2-treated plants exhibited the highest increase in root yield and the regulation effects of soluble sugar content in tuberous roots was different among cultivars. This study provides a theoretical basis for industrial development of raw-edible sweetpotato both in quality and in efficiency and for the technologies of ecological planting. %U https://www.hnxb.org.cn/EN/10.11869/j.issn.100-8551.2019.05.1016