甘薯块根抗黑斑病酚类物质代谢的研究

研究甘薯块根酚类物质代谢与抗黑斑病之间的关系，为鉴定和选育抗黑斑病品种提供抗性指标。以‘南京-92’（高抗）和‘烟台-252’（高感）为材料，测定了甘薯块根中绿原酸、总酚的含量、多酚氧化酶(PPO)、苯丙氨酸解氨酶(PAL)的活性。抗病品种在黑斑病侵染第1天，PAL活力就迅速提高，以后的几天一直保持较高水平。感病品种在黑斑病侵染后第3天PAL活力才显著升高、5天后就迅速下降；黑斑病侵染使甘薯绿原酸含量迅速提高，但不同抗病性的甘薯品种积累的时相和量有所不同，高抗比高感提高56.6%~327%；受黑斑病浸染后，高抗品种体内PPO活性及和总酚含量比高感品种提高迅速，且持续的时间较长。甘薯块根中PAL活性、绿原酸含量、多酚氧化酶活性、总酚含量的提高，有利于提高甘薯抗黑斑病的能力。

The Study on Phenol Metabolism in Sweet Potato Infected by Ceratocystis fimbriata Ellis et Halsted

The aim was to study the relationship between the phenol metabolism and the resistance to Ceratocystis fimbriata Ellis et Halsted in sweet potato, and provide the resistant indices for identification and selection of C. fimbriata Ellis et Halsted. ＇Nanjing-92＇ （High resistance） and ＇Yantai-252＇ （High infection） were chose as material. The inoculating experiment on the disease fungi of the resistant and sensitive varieties was conducted to study the effects of C. firnbriata Ellis et Halsted on chlorogenic acid and total phenol content, PPO and PAL activity. The PLA activity of high resistant variety increased rapidly （one day later） and maintained higher lever in the next few days after it had been infected by C. fimbriata Ellis et Halsted. The PLA activity of high susceptible variety increased significant （three days later） and decreased rapidly （five days later） after it had been infected by C. fimbriata Ellis et Halsted. The chlorogenic acid content of two varieties increased rapidly after there had been infected by C. fimbriata Ellis et Halsted. However the chlorogenic acid content of high resistant variety was 56.6%-327% higher than that of high susceptible variety. The PPO activity and total phenol content of high resistant variety increased rapidly and the relay time was longer than that of high susceptible variety after there had been infected by C. fimbriata Ellis et Halsted. The resistance of sweet potato to C. fimbriata Ellis et Halsted would be increased with the increase of PLA activity, chlorogenic acid content, PPO activity and total polyphenol content.