目的探明棉花黄萎病对不同伤根程度棉苗体内相关抗性酶的影响。方法棉苗长至四叶时,将纸钵与蛭石等去掉,用水小心冲刷,得到:⑴完整根苗。⑵将根下部3～5cm的余根用消毒的刀切掉为切根苗。⑶留主根,将大部分侧根切除为伤根苗。3种不同根系状况的棉苗浸于20ml棉花黄萎病菌的菌液中,以无菌水稀释至不同浓度。经0～48h,记载致萎蔫程度,并测定相关抗性酶的变化。结果3种伤根处理的棉苗浸黄萎病菌培养液后,其致萎度差异显著。当病菌液的浓度为1﹕10时,整根苗不出现感病,受害最轻;其次为伤根苗,2级感病;切根苗最为严重,3级感病。同时还测定了与提高抗病性有关酶的变化,以1﹕50浓度处理效果最好,过氧化物酶(POD)活性伤根苗达42.96Umg-1·min-1,整根苗达到较高值49.2Umg-1·min-1,切根棉苗为38.2Umg-1·min-1。有害物质丙二醛(MDA)的含量切根棉苗为39.483mmol·g-1,伤根苗为27.12mmol·g-1,整根苗为最低值3.845mmol·g-1。而体内相关抗性酶如过氧化物酶(POD)活性的高低与有害物质丙二醛(MDA)含量的多少,其顺序与受害轻重的顺序一致。结论棉花伤根后的棉苗外部病理反应与体内相关酶的动态生化反应进行研究,获得植株外部病理反应与内部生化实验相吻合的结果。 Objective To investigate the effects of cotton Verticillium wilt on the related resistant enzymes in cotton seedlings with different injury levels. Method Cotton seedlings grow to four leaves, the paperboard and vermiculite and other removed, carefully washed with water to get: ⑴ complete root seedlings. ⑵ root 3 ~ 5cm under the root with a sterile knife cut off cut rooted seedlings. ⑶ stay the main root, most of the lateral root excision wound root seedlings. Cotton seedlings with 3 different root conditions were immersed in 20 ml of the bacterial wilt of Verticillium dahliae and were diluted to different concentrations with sterile water. After 0 ~ 48h, the degree of wilting was recorded and the changes of related resistant enzymes were measured. Results Three kinds of wounding cotton seedlings treated Verticillium dahliae culture medium, its significant difference in the degree of fade. When the concentration of bacteria solution is 1:10, the whole root does not appear susceptible to the disease, the least damage; followed by injury root seedlings, grade 2; cuttings most serious, grade 3 susceptible. At the same time, the changes of enzymes related to disease resistance were also determined. The treatment with 1:50 concentration had the best effect. The peroxidase (POD) -activated roots reached 42.96Umg-1 · min-1, 49.2Umg-1 · min-1 and 38.2Umg-1 · min-1. The content of malondialdehyde (MDA) in the cuttings was 39.483 mmol · g-1 for cuttings and 27.12 mmol · g-1 for the seedling root, and the lowest value was 3.845 mmol · g-1. However, the order of the related resistance enzymes such as peroxidase (POD) activity and malondialdehyde (MDA) content in the body is consistent with the order of severity of the damage. Conclusion The external pathological reaction of cotton seedlings and the dynamic biochemical reaction of related enzymes in cotton plant after wounding of cotton roots were studied. The results showed that the external pathological reaction of plant was consistent with the internal biochemical experiments.