Effect Of Different Additives On Virus-free Potato Seedlings And Enzyme Activity Analysis

Nowadays, potato is one of the four major food crops in human society. With the characteristics of high yield, rich nutrition, strong adaptability, high economic value, is widely cultivated in the world. Viruses and viroids not only lead to the degeneration of genuses but also cause a lot of diseases which restricted the improvement of the quality and yield. Taked MS and1/2MS as basic culture medium, changed6kinds of carbon sources, for example, sucrose, soft sugar, fructose, glucose, maltose and starch.5kinds of nitrogen sources, for example, KNO3, Ca(NO3)2, NH4NO3,(NH4)2SO4NH4Cl. The ratios of NO3--N/NH4+-N were from1:1to6:1, also added urea and activated charcoal. Cultivated ZaoDaBai potato virus-free seedlings and compared the effects of different additives on virus-free seedlings. Configured the different additives and the best culture medium for ZaoDaBai potato virus-free seedlings.The results showed that, the concentrations from2.0%to2.5%of sucrose and soft sugar were better than the other carbon sources. They were of benefit to rapid propagation and promoting strong.0.1mol/L KNO3or0.2mol/L NH4NO3were better than other nitrogen sources. The ratios of1:1and5:1were better in height growth, leaf numbers, root length than others. Urea as an additional nitrogen source added in culture medium was not play significant role in promoting ZaoDaBai potato virus-free seedlings. The concentrations from0.1%to0.2%of activated charcoal played promote role in potato virus-free seedlings’cultivation. Experiments showed that, the best culture medium for ZaoDaBai virus-free potato seedlings, soft sugar was2.0%, ratio of NO3-N/NH4+-N was1:1and activated charcoal was0.1%.During the time of plants’ growing, it was unavoidable that the plant would be adhering and invaded by the pathogenic microorganism. After a long period of evolution and development, the plant produced mechanism of stress resistance by itself. During the process of plant resistance, some enzymes of disease resistance such as SOD, POD, CAT, PPO produced phytoalexins which led to the synthesis of lignin and strengthen the degree of cell lignifications to protect the plant. But some infected enzymes such as cellulose and pectinase would lead to cell degradations which was the factor for plant disease. Six kinds of enzymes analysis in this experimentation, we knowed that stem tip virus-free could improve the activity of enzymes of disease resistance efficiently.The activity of SOD, POD, CAT, PPO in virus-free seedlings was higher than that in virus-carrying plant separately, the data were140.45,324.79,21.2and8.25. But the activity of the cellulose and pectinase in virus-carrying plant were3.4and87.45times higher than that in virus-free seedlings. Similar to the former, the virus-free tude seedling produced at the optimized medium was better than that produced at the MS medium at the activity of SOD, POD, CAT, PPO. But the activity of cellulose and pectinase were lower. All of these provided the the oretical basis for cultivating healthy detoxified potato virus-free seedlings.