The Relation Between The Changes Of Physiological And Biochemical Indices And Resistance Of Potato Plants Infected With PVY

SOD activity, Vc, proline and dry matter contents of three genotypes, Desiree with hypersensitive, IVP35 with resistance and Superior susceptible to PVY, were investigated before and after inoculation with PVY. The results were as following:Without inoculation, the SOD contents of susceptible cultivar (Superior) is much lower than that of both hypersensitive cultivar (Desiree) and extremely resistant clone ( IVP35). After infecting, SOD content of IVP35 was going down slightly. However, the SOD activity of Desiree went down at the beginning of Infection (0.5-Id), then (2d-7d) it increased renewedly, and it declined again at last (7d-14d). SOD activity of Superior was rising after infected with PVY. Less changes of SOD contents both IVP35 and Desiree were showed when they were infected by PVY, and the maximum was showed in 2 to 3 days after infection. The less changing rates of SOD activity of both Desiree and IVP35 were showed after infection with PVY, and their changing ranges were -13.4% to 4.6% and -17.8% to 8.7% respectively. SOD activity of Superior was changed greatly after infection with PVY, and the range was 5.1% to 79.2%.Proline contents of IVP35 and Desiree were higher than that of Superior no matter they were infected or not Without infection, proline contents of IVP35 and Desiree were 41.39 to 48.77ug/g.d.w. and 3.42 to 39.11ug/g.d.w. respectively. However, the proline content of Superior was only 8.91 to 10.72ug/g.d.w. With infection, proline content of Superior went up significantly, and its range was 11.23 to 21.54ug/g.d.w. Similarly, the proline contents of IVP35 and Desiree increased as well, but changing scopes were little, which were 48.92 to 72.13ug/g.d.w. and 42.46 to 71.34ug/gd.w.After infection by PVY, Vc contents of Superior increased evidently, and the scope was 2.9% to 151.6 %. Vc content of Desiree increased as well, but less changing scope that was 2.5% to 15.5%. Almost no any change happened with IVP35 or declined slightly.The dry matter contents of Desiree and Superior declined by 25.9% and 17.2% respectively, but less change appeared in IVP35 when they were infected with PVY.