低浓度玉米小斑病菌C小种毒素培养滤液诱导寄主抗性的研究

Induced Host Disease by Culture Filtrate of Bipolaris maydis Race C Toxin Cultivation in Maize(Zea mays L.)

利用低浓度玉米小斑病菌C小种毒素培养滤液作为激发子诱导玉米获得抗病性。以一对同核异质玉米B37自交系为试材,采用离体叶片接种法检测适宜诱导抗性的低浓度玉米小斑病菌C小种毒素培养滤液作为激发子诱导玉米抗病性的适宜诱导浓度,测定与抗病性相关酶的变化。经用1∶50和1∶60的低浓度玉米小斑病菌C小种毒素培养滤液预处理植株,再接种高浓度（1∶10）毒素培养滤液处理的病斑面积分别为（0.30±0.14）和（0.36±0.17）mm2,而对照为（2.70±0.24）mm2,是处理的7.5-9倍,差异极显著。经0-72 h的动态检测,以1∶60预处理效果为最佳,与对照相比,苯丙氨酸解氨酶（PAL）活性平均提高了23.4%,过氧化物酶（POD）活性平均提高了65.9%,有害物质丙二醛（MDA）的含量平均降低了28.2%。叶片内部所产生的生化反应与叶片表面的抗性病理反应相吻合,证实低浓度玉米小斑病菌C小种毒素滤液本身能够成功地作为激发子来诱导寄主-玉米获得抗性。

Disease to maize southern leaf spot disease was induced by culture filtrate of Bipolaris maydis race C toxin cultivation. A pair of homokaryon B37 inbred lines in maize was used as the test material. The toxin activity was measured by the detached leaf method to find its optimal concentration as a plant defense activator that induces maize disease resistance, and several enzymes involved in disease resistance were presented. The lesion area on the leaves was significant difference by ANOVA. They were （0.30 ± 0.14） and （0.36 ± 0.17） mm^2 respectively after pretreated with 1：50 and 1：60 of culture filtrate of Bipolaris rnaydis race C toxin cultivation were （0.30± 0.14） and （0.36 ±0.17） mm^2 respectively. It was decreased 7.5- 9 times compared with the CK （2.70 ± 0.24） mm^2. At the same time, the changes of peroxidase （POD）, phenylalanine ammonialyase （PAL）, malondialdenvde （MDA） activities were determined. During 0 - 72 h inspection, the effect of 1 ： 60 concentration was better than that of 1 ： 50, PAL activity increased by 23.4 %, POD activity increased by 65.9 %, but the malondialdenvde （MDA） content decreased by 28.2 % compared with the CK. It was shown that culture filtrate of Bipolaris maydis race C toxin cultivation itself can function as an elicitor to induce host disease resistance in maize .