摘要
在甘薯抗病品种Ｃ１８０、金山５７与感病品种岩薯８－６和南惠７号接种蔓割病菌后第２、４、６和８ｄ，分别测定叶片脂质过氧化水平及体内若干保护酶的活性．发现接种后第８ｄ病株的脂质过氧化产物丙二醛（ＭＤＡ）高于未接种的健株，感病品种的高于抗病品种的；随着接种时间的延长，超氧物歧化酶（ＳＯＤ活性逐渐下降，感病品种下降的速率高于抗病品种的；接种第４ｄ，抗、感病品种过氧化氢酶（ＣＡＴ）活性均出现高峰，第６、８ｄ活性下降，感病品种下降速率大于抗病品种；抗病品种接种第６ｄ过氧化物酶（ＰＯＤ）活性出现高峰，随后又下降，而感病品种活性高峰迟出现，在接种的８ｄ内持续上升．研究表明甘薯品种对蔓割病的抗性与脂质过氧化及体内保护酶系统有着密切的关系．
Abstract The peroxidization level and the protective enzyme activities of plasma membrane were deterimined in 2, 4, 6 and 8 days inoculated stem rot pathogen against sweet potato cultivare: the desease-resistant C180, Jinshan 57 and the desease-sensitive Yansu 8-6, Nauhui 7. It was found that malondiadehyde (MDA) content in the infected plant was higher than that in the uninoculatedly heathy plant, and the sensitive higher than the resistant. With the increase of inoculation time, superoxide (SOD) activity gradually decreased,and decrement in the sentitive was higher than that in the resistant. The summit of catalase (CAT) activity appeared in the 4 day inoculation, but in 6 day and 8 day inoculation the activity decreased,the decrement of the senaitive higher than the resistant. The summit of peroxidase (POD) activity in the resistant appeared in 6 days inoculation,then gradually lowered. However, the POD activity in the sensitive gradually increased within the 8 day inoculation.All above results indicated that the reaistance of sweet potato stem rot was highly related to the peroxidization of plasma membrane and its protective enzymes,and provided the theorietic basis for clarifiction the resistant mechanism and for identification the cultivar resistance to sweet potato stem rot.
