Effects Of Plastic Mulching And Fertilization On The Accumulation Of Anthocyanin Content In Purple Sweet Potato Roots

Anthocyanin,as a natural antioxidant active substance riching in purple sweet potato,is an important indicator to measure the nutritional quality of purple sweet potato.Anthocyanins have attracted much attention due to their antioxidant and mutation resistance,and the content of anthocyanins in purple sweet potatoes is high,so purple sweet potatoes are used as an important source of anthocyanins.The synthesis and accumulation of anthocyanins are regulated by internal and external factors.At present,the research on increasing anthocyanin is mostly focused on promoting the color development mechanism by inducing gene expression related to the anthocyanin synthesis pathway,but there are few researches on the color development mechanism of plant underground organs by cultivation factors.In this study,by setting different mulching methods and fertilization gradients,the effect of mulching and fertilization on the accumulation mechanism of purple sweet potato anthocyanin content was studied.The main results are as follows:1.In the pre-growth,mid-growth and late-growth stages of purple sweet potato,the number of basal branches,the number of leaves,the thickness of the main stem,the length of the main vine node,the length of the main vine,grows in different mulching,different fertilization performance: in three growth periods,the number of basal branches,the number of leaves,the thickness of the main stem,the length of the main vine node,the length of the main vine of Qinzi 2 and Violet are more affected by the combined application of PK fertilizer,and the lower concentration Fertilization can more effectively improve the growth of the above-ground parts,while the black film can better promote the growth of the above-ground parts.2.The performance of purple sweet potato’s root-shoot ratio,dry matter rate,and yield in the pre-growth,mid-growth and late-growth stages of purple sweet potato under different fertilization and different film mulching: in the three growth periods,Qinzi 2 and violet’s root-shoot ratio,dry matter rate,and yield are more affected by the combined application of PK fertilizers.In the fertilization gradient T2,the root-shoot ratio,dry matter rate,and yield are larger,indicating that the appropriate fertilization concentration will increase the root-shoot ratio,dry matter rate,yield,and covering black film and white film have a greater promotion effect on root-shoot ratio,dry matter rate and yield than no film.(1)Root-shoot ratio: Qinzi 2 PK combined application<single application of P fertilizer<single application of K fertilizer,white mulching<no mulching<black mulching;violet single application of P fertilizer<PK combined application<single application of K Fertilizer,no film<black film<white film.(2)Dry matter rate: potato dry rate Qinzi 2 PK combined application <single application of P fertilizer<single application of K fertilizer,no mulching <black mulching <white mulching;violet single application of P fertilizer <single application of K fertilizer <PK with application,no film coating<black film coating<white film coating Vine dry rate Qinzi 2 single application of K fertilizer<PK combined application<single application of P fertilizer,no mulching <black mulching <white mulching;violet single application of P fertilizer<single application of K fertilizer<PK combined application,white covering mulching <no mulching <black mulching.(3)Yield: Qinzi 2 PK combined application <single application of P fertilizer <single application of K fertilizer,no film mulching <white film mulching <black film mulching;violet PK combined application<single application of P fertilizer <single application of K fertilizer,white mulching <no mulching <black mulching.3.The performance of anthocyanin content and its synthetic precursor substances glycogen,phenylalanine and related synthetic enzymes in different fertilization and different film mulching in the pre-growth,mid-growth and late-growth stages of purple sweet potato: In the three growth periods,Compared with single application of K and P,the anthocyanin content was significantly increased under PK combined application and at a lower fertilization gradient.At the same time,compared with no mulching and white film mulching,the anthocyanin content was significantly increased under black film mulching.The penicillin content has also increased to a certain extent.Screening was performed according to the level of anthocyanin content,and the selected purple potato tubers under PK treatment were further analyzed.In this study,the prerequisite for anthocyanin synthesis,reducing sugar,water-soluble sugar content,and phenylalanine concentration were all greater when PK was applied and the fertilization gradient was low;compared with no film and white film,black film,the glycogen content is higher under the membrane treatment.The key enzymes in the five stages of the anthocyanin synthesis pathway have higher activities under the treatments with no mulching and black film mulching,and the enzyme activity of low fertilization gradient is larger than high fertilization gradient.In general,Qinzi 2 and Violet under the conditions of PK combined application,lower fertilization gradient,and black film mulching,the above-ground plant growth is better,the anthocyanin content of under-ground root and the concentration of synthesis related substances are also higher.Analyzing the accumulation mechanism of anthocyanin synthesis in purple sweet potato under-ground root provides some theoretical guidance.