枯萎病菌对不同抗性黄瓜品种几种酶活性的影响

Effects of Fusarium wilt pathogen on the enzyme activity of cucumber cultivars of different resistance

用枯萎病菌接种不同抗性黄瓜品种,研究不同抗性黄瓜品种的过氧化物酶(POD)、多酚氧化酶(PPO)和几丁质酶的活性变化。结果表明,接种后抗感品种POD、PPO和几丁质酶活性基本都呈现先升后降再升(再降)的趋势。抗感品种均在接种后12h时出现第1次POD活性峰值,抗病品种中农13号、津优3号分别在接种后60、72h、感病品种在84h出现第2次POD活性峰值;接种后24h时抗感品种均达到第1次PPO活性峰值,抗病品种在48h、感病品种在60h时达到第2次PPO活性峰值;接种后抗病品种在48h时达到第1次几丁质酶活性峰值,72h时达到第2次峰值,而感病品种只在60h时出现1次几丁质酶活性峰值。抗感品种的POD、PPO、几丁质酶活性的2次峰值都显著或极显著地高于各自的对照,在接种后的早期阶段,感病品种的POD、几丁质酶活性的第1次峰值都显著或极显著地高于抗病品种,PPO活性的第1次峰值极显著地低于抗病品种。

The dynamic changes in peroxidase （POD）, polyphenoloxidase （PPO）and chitinase activities of different resistant cucumber cultivars were studied by inocutating the pathogen of the fusarium wilt . The results showed that the POD, PPO and chitinase activities of all cultivars tested increased firstly, then decreased and increased finally. Twelve hours after inoculation, the first peak of POD activity of all cultivars appeared and the second peak of POD activity in Zhongnong 13 and Jinyou 3 resistant cultivars and susceptible cultivars appeared at 60 hours, 72 hours and 84 hours after inoculation, respectively. Twenty four hours after inoculation, the first peak of PPD activity of all cuhivars appeared, and the second peak of resistant eultivars and susceptible cultivars appeared at 48 hours and 60 hours after inoculation, respectively. The first peak of chitinase activity of all cultivars appeared at 48 hours after inoculation, and the second at 60 hours. The peak of susceptible cultivars only appeared at 60 hours. Generally speaking, two peaks of POD. PPO and chitinase activities were significantly or extremely significantly higher than the controls. At the early stage after inoculation, the first peaks of POD, PPO and chitinase activities in susceptible cultivars were significantly or extremely significantly higher than the controls. The POD, PPO and chitinase activi ties could be used as the evaluation indexes to select different resistant or susceptible cucumber cuhivars.