与甘蓝黑腐病抗病相关的酚类物质测定

Study on the phenolics to resistant black rot in cabbage

为探寻甘蓝抗黑腐病的生理生化机制，以抗病材料C7和感病材料C26为试验材料，在甘蓝幼苗4～5片真叶期，喷施菌液浓度为1．0×10^8cfu·mL^-1的细菌悬浮液，以喷施蒸馏水为对照，对2种材料叶片的苯丙氨酸解氨酶（PAL）活性、抗病相关酚类物质和木质素含量变化进行研究。结果表明：与对照相比，接种后2d，C26的PAL活性显著增加，并达到峰值；此后，C26的PAL活性迅速下降，接种后5d与对照无显著差异；C7的PAL活性分别于接种后2、4d出现峰值，此后活性下降。c7和C26接种菌液后，酚类物质和木质素含量均高于对照，且于接种后3d达到峰值，此后呈下降趋势；接种后5d，C26叶片中酚类物质和木质素含量与对照无显著差异，但C7仍保持较高水平。

Black rot, caused by Xanthomonas campestris pv. campestris （Xcc）, has been reported as a major con- straint in cabbage production and quality. In order to explore the relationship between the resistance to cabbage black rot and the activity of phenylalanine ammonia-lyase （PAL）, accumulation of phenolies and lignin contents. C26 and C7, two cabbage cultivars of different disease resistant capacity, were treated with 1.0 × 108 cfu·mL^-1 at four to five leaves, while the other group was sprayed distilled water as usual （Control, CK）. The result showed that compared to CK, the PAL activity of C26 increased significantly after 2 days, reached the highest level in 2 d, and decreased rapidly after 5 days. The PAL activity of C7 reached the highest level in 2 and 4 days, and then decreased. The phenolics and lignin contents of two varieties inoculated with Xcc increased rapidly and reached the highest level in 3 d. After 5 days, the phe nolies and lignin contents in C26 decreased rapidly, but those in C7 still maintained higher level.