The Influence Of The Old Apple Orchard Soil On The Growth Of Prunus Persica Grafted Seedlings And The Remission Of Potassium Permanganate

The experiment was investigated in the national laboratory center for apple engineering of Shandong Agricultural University from March 2015 to March 2017.Effect of the 25 years old apple orchard soil and wheat field soil which was sampled from manzhuang town of tai'an city of shandong province on the growth of Prunus persica grafted seedlings and remission of potassium permanganate were researched in the pot experiment.The main results were as follows.1.Compared to wheat field soil,the growth of Prunus persica grafted seedlings planted in old apple orchard soil was significantly reduced.The fresh and dry weight of seedlings were reduced by 28.11% and 35.66%,respectively.The root activity of seedlings planted in old apple orchard soil was also reduced by 33.04%.In addition,the superoxidase(SOD),peroxidase(POD)and catalase(CAT)activity of seedlings were also significantly reduced by 52.15%,46.01% and 27.94%,respectively.Furthermore,malondialdehyde(MDA)of Prunus persica grafted seedlings increased significantly,which were 2.13 times than the seedlings planted wheat field soil.2.Apple orchard soil significantly reduced the number of soil bacteria,increased the number of soil fungi,changed the structure of the soil fungal community,decreased the soil enzyme activity.Compared to wheat field soil,the number of soil bacteria of old apple orchard reduced by 70.83%,however the number of fungi increased by 99.94%,and the ratio of bacteria and fungi reduced significantly.In addition,the T-RFLP results showed that the simpson index of fungi increased,but the shannon index,pielou index and margalef index reduced significantly.The urease,sucrase and neutral phosphatase activities were also reduced by 77.24%,67.18% and 26.45%,compared to wheat field soil.3.Phloridzin had significant inhibitory effects on the biomass and the root activity of Prunus persica grafted seedlings.Compared to wheat field soil,the fresh and dry weight of seedlings reduced by 16.66% and 20.11% respectively.However,both phloridzin and phloretin reduced the root activity of Prunus persica grafted seedlings by 20.83% and 49.81%,respectively.4.Furthermore,phloridzin also reduced autioxidant enzyme activities and increased the contents of MDA in the root of Prunus persica grafted seedlings.Compared to the seedlings planted in the wheat field soil,phloridzin significantly reduced the SOD and POD activities by 40.80% and 31.11%,respectively.And content of MDA was 2.16 times than the seedlings planted in the wheat field soil.5.Potassium permanganate improved the growth of Prunus persica grafted seedlings planted in the old apple orchard soil.Compared to the seedlings planted in the wheat field soil,the fresh weight,dry weight and root activity of seedlings treated by potassium permanganate were increased by 62.11%,58.85% and 49.19%,respectively.And the SOD,POD and CAT activities were also increased by 56.69%,102.40% and 109.83%,respectively.However,the content of MDA was reduced by 31.50%.6.Potassium permanganate reduced the content of phloridzin in the old apple orchard soil.Compared with the control,the content of phloridzin treated by potassium permanganate was significantly reduced by 57.80%.7.Furthermore,potassium permanganate also changed the microbial community structure significantly in the old apple orchard soil,reduced the number of fungi significantly,by 41.79%,and enhanced the ratio of bacteria and fungi,by 103.13%.In addition,the result of T-RFLP showed that the simpson index of soil treated by potassium permanganate reduced significantly,but the shannon index,pielou index and margalef index were increased significantly.It meant that potassium permanganate improved the microbial community structure of the old apple orchard soil.