The influence of the Verticillium dahliae Kleb infection on cotton’s anti-enzyme

chinois. 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。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3～5 cm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20 ml棉花黄萎病菌的菌液中，以无菌水稀释至不同浓度。经0～48 h，记载致萎蔫程度，并测定相关抗性酶的变化。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1s10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1s50浓度处理效果最好，过氧化物酶（POD）活性伤根苗达42.96 U mg-1and#8226;min-1，整根苗达到较高值49.2 U mg-1and#8226;min-1，切根棉苗为38.2U mg-1and#8226;min-1。有害物质丙二醛（MDA）的含量切根棉苗为39.483 mmoland#8226;g-1，伤根苗为27.12 mmoland#8226;g-1，整根苗为最低值3.845 mmoland#8226;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。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。

anglais. The objective was to explore the influence of the Verticillium dahliae inflection on cotton’s the anti-enzyme. The research looked at the degree of injury inside the body. Long cotton seedling with four leaves which were flushed with water carefully. Three types of seedlings were used in the experiment:(1)Complete root seedling, (2) Cut root seedling Ccutting off the lower part 3-5cm of the root by a disinfected knife, (3) Injured root seedling Ccutting off greatly the parts of side root but staying the main root.The three kinds of cotton seedlings with different roots were immersed separately in different concentration of the germ liquid (V. dahliae) 20ml each. Through the first 48 hours,the wilt degree of the seedling were recorded, and the related anti-enzyme of the variety was measured. After immersed in the germ liquid, the wilt degree of the three kinds of injured root were significantly different. When the germ liquid was at a ratio of 1:10, the complete root seedling was lightest and had no wilt; the injured root seedling had 2 -degree wilt. The cut root seedling had the most noticeable wilt. At the same time, the changes in peroxidas, and malondialdehvde activities were determined. Peroxidase (POD) activities of cut-root seedling were 38.2Uand#8226;mg-1and#8226;min-1, injured root seedling were 42.96 Uand#8226;mg-1and#8226;min-1, and the complete root seedling was the highest with 49.2 Uand#8226;mg-1and#8226;min-1. The malondialdenvde (MDA) content of cut-root seedling was 39.483mmoland#8226;g-1, injured root seedling was 27.12 mmoland#8226;g-1，and the complete root seedling was only 3.845 mmoland#8226;g-1. After modifying the young roots, the exterior pathological reaction of the seedling and the dynamic state bio-chemical reaction of the related enzymes inside the plant body were studied. It showed that the plant exterior pathology responded to the test with respective internal bio-chemicals.