昆明学院学报

为认识烟草嫁接组合(嫁接烟株)受到烟草黑胫病(Phytophthora nicotianae)为害后，根系中主要生理生化指标的变化，及上述变化与嫁接烟株抗性的相关性，开展盆栽试验.对嫁接和自根苗根系烟株接种烟草黑胫病菌，检测其根系中主要防御相关的苯丙氨酸解氨酶(PAL)、多酚氧化酶(PPO)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)活性和丙二醛(MDA)含量，对比分析上述指标变化与抗性的相关性.结果发现，砧木自根苗云烟303和G278表现为抗病和中感，接穗自根苗红花大金元(红大)为感病，嫁接组合云烟303+红大为抗病、G278+红大为中抗.嫁接组合云烟303+红大、G278+红大接种黑胫病菌后，除根系中SOD活性呈现先降低后升高的变化趋势外，PAL、PPO、CAT、POD活性均有不同程度的升高，呈现先升高后降低的变化趋势.云烟303+红大根中防御酶活性增减幅多介于其接穗自根苗和砧木自根苗之间或显著大于砧穗自根苗对照，而G278+红大根中防御酶活性增减幅均显著大于砧穗自根苗对照.嫁接组合云烟303+红大和G278+红大根中MDA含量均呈不同程度的升高，最大增幅显著高于砧穗自根苗，但在不同时期增减比率波动较大.分析结果表明，嫁接组合云烟303+红大、G278+红大的抗病性与根系中PPO和CAT的活性增幅存在正相关，但与PAL、POD、SOD活性和MDA含量变化的规律性不明显.试验结果为进一步认识嫁接烟株根系主要生理生化指标变化与烟株黑胫病抗病性的关系提供了资料，对应用嫁接烟株防治烟草黑胫病有重要的参考价值.

To recognise the changes in major physiological and biochemical indices in the roots of tobacco grafted combinations(grafted tobacco plants) after they are affected by tobacco black shank(Phytophthora nicotianae),and whether their changes are correlated with the resistance of grafted tobacco plants, a pot experiment was conducted. The main defence-related enzymes PAL,PPO,SOD,CAT,POD activities and MDA contents in the roots of grafted tobacco plants and self-root seedlings were tested in pots inoculated with P. nicotianae, and whether their changes were correlated with resistance was analysed comparatively. The self-root rootstocksYunyan 303 and G278 were resistant and moderately susceptible, the self-root scion HonghuaDajinyuan(HDa) was susceptible, and the grafted combinations Yunyan 303+HDa was resistantand G278+ HDa was moderately resistant. After the grafted combinations Yunyan 303+HDa and G278+HDa were inoculated with P. nicotianae, thePAL,PPO,CAT and PODactivities increased to different degrees and showed the trend of increasing and then decreasing, except for SOD in the roots, which showed the trend of decreasing and then increasing. The increase and decrease of defence enzymes in the roots of Yunyan 303+HDa was mostly intermediate between the self-root scion and the self-root rootstock or significantly greater than the self-root scion and rootstock, G278+HDa was significantly greater than the self-root scion and rootstock. Grafted combinations Yunyan 303+HDa and G278+HDa roots in the MDA content were all different degrees of elevation, but in different periods of increase and decrease ratio fluctuations, Yunyan 303+HDa and G278+HDa MDA maximum increase were significantly greater than the self-root scion and rootstocks. There was a positive correlation between the disease resistance of grafted combinations Yunyan 303+HDa and G278+HDa and the increase in the activities of PPO and CAT in the roots, but the regularity of the changes in the PAL,POD,SOD activities and the MDA content were not obvious. The experimental results provide information for further understanding the relationship between the changes of major physiological and biochemical indexes in the roots of grafted tobacco plants and their resistance to tobacco black shank, which is of reference value for the application of grafted tobacco plants for the control of tobacco black shank.