过氧化物酶与不同甜瓜品种对小西葫芦黄化花叶病毒抗性的关系

研究了对小西葫芦黄化花叶病毒新疆株（Zucchiniyellowmosaicvirus-Xinjiangstrain,ZYMV）抗性不同的甜瓜品种受病毒感染后过氧化物酶活力及其同工酶谱的变化．与健康对照相比,受感染植株的酶活力均有所增高,但不同抗性品种受感染植株酶活力增高的幅度、酶活力高峰出现的时间和同工酶谱带的增多,均表现与抗性相关的规律性差异．抗性品种“新玉”的酶活力增高幅度是感性品种“网纹香”的2倍,酶峰早出现12d;2条只在感染植株中出现的同工酶带C和E在“新玉”中较“网纹香”中早出现15d,并多维持12d．抗性居中的品种“红心脆”和“向里黄”的以上指标则居“新玉”和“网纹香”之间．2条健康对照和感性品种都不存在的酶带H和I,则仅在抗性较强的品种中出现．

THE RELATIONSHIP BETWEEN PEROXIDASES ADN RESISTANCE OF MUSKMELON CULTIVARS TO ZYMV

Changes of peroxidase activity and isoperoxidase in muskmelon cultivars of different resistance to zucchini yellow mosaic virus (ZYMV) were investigated. The results indicated that there were regular differences relative to the resistance in the increase of peroxidase activity ,the appearance time of peroxidase activity peak and the number of isozyme bands between infectedplants and healthy control. The increase in peroxidase activity for asistant cultivar "Xinyu" was two times of that for susceptible cultivar "Wangwenxiang" and the peak of enzyme activity for "Xinyu" appeared 12 days earlier. Two additional isoperoxidase bands Cand E, which occured only in the case of infected plants, appeared 15 days earlier and maintained 12 days more in "Xinyu" than in "Wangwenxiang". The above indexes in medium resistant cultivars "Hongxincui" and "Xianglihuang" were between "Xinyu" and "Wangwenxiang". Two additional isozyme bands H and I appeared in the resistant cultivars only but not in healthy control and susceptible cultivars. The regularity of changes of peroxidase activity and isoperoxidase can be used as the biochemical criterion for the determiation of susceptibility and resistance to ZYMV for muskmelon cultivars.