Effects Of Branches Returning On The Autotoxins And Microbes In Soil And Tree Growth Of Peach

1. This study aimed to find out the effects of branches returning on the growth of peach saplings, soil enzymes activity, soil phenolic acid and amygdalin contents, thereby providing the scientific basis for the application of branches returning on peach. Four kinds of agricultural strategies were applied in this study, which were 1.5 g/kg peach tree branches fragments covered returning, 22.5 g/kg peach tree branches fragments covered returning, 1.5 g/kg peach tree branches leaching solution poured returning, 22.5 g/kg peach tree branches leaching solution poured returning, and no branches added as control(CK), with one-year-old potted peach tree ‘chun mei /wild peach’ as the material. Compared with CK, the phenolic acid and amygdalin contents significantly increased compared with CK after the high quantity branches fragments covered treatment and leaching solution poured returning treatment. The soil microbial community structure altered in both treatments, and the proportion of fungi in soil, particularly Agaricomycetes, Tubeufia and Cystofilobasidiaceae increased significantly while the proportion of the bacteria decreased specifically. Soil invertase activity of high quantity covered and leaching solution poured treatment exceeded control significantly.The soil catalase and urease acitivity was higher at first and then becoming lower than control under high quantity covered and leaching solution poured treatment. In detail, the long-term impact of high quantity covered treatment was marked, while the leaching solution poured treatment significantly effected in the short-term. The chlorophyll content, trunk girth and net photosynthesis rate of plants in high quantity covered and leaching solution poured treatment were lower than that in control, with the new shoots stagnated becoming advance. We can see an increase on soil phenolic acid and enzymes when treated with normal pruning quantity, while no inhibition effect was found on the tree growth. In conclusion, the soil enzyme activity changed with the accumulation of autotoxins, such as phenolic acid and amygdalin, thus depressed the growth of peach trees. Overall, branches returning inhibited the growth of peach saplings at high concentration while no effect at normal concentration.n of branches returning on peach trees.2. This study aimed to find out the effects of branches returning on the growth of peach saplings, soil enzymes activity, soil phenolic acid and amygdalin contents, with two-year-old field peach tree ‘chun mei /wild peach’ as the material. The results showed that, normal amount of peach tree branches retuning treatment had no significant difference in content of laetrile, microorganisms, soil enzyme activity and peach tree growth indicators, compared with CK. Visible, in the short term, there was no effect on peach soil laetrile, phenolic acids and palnt growth at normal concentration of peach tree branches returning.3. Current year peach seedlings were selected to study the effects of adding different concentrations of exogenous autotoxins, vanillin and benzoic acid on the growth of peach plant. The results showed that, POD enzyme activity in roots was significantly increased after 0.5mM autotoxins treatment, while the CAT activity and root vigor was significantly inhibited. When the treated concentration was 1mM, activity of SOD and CAT were inhibited after autotoxins treatment. And exogenous 1mM vanillin and benzoic acid treatment significantly reduced the activity of protective enzymes in the root, root vigor, root shoot ratio, SPAD value and net photosynthetic rate. 1m M Vanillin treatment also significantly reduced the total potassium content in the leaves. The activity of protective enzymes in the root, root vigor, root shoot ratio, SPAD value, net photosynthetic rate and total nitrogen/ phosphorus/potassium content in the leaves were decreased significantly after treated by 3mM autotoxins, vanillin, benzoic acid and their mixture. These results indicated that the growth of peach seedlings was inhibited by 1mM vanillin, 1mM benzoic acid and 3mM autotoxins. And as the treated concentration increases, the inhibition increased.