禾谷缢管蚜取食5种山羊草的诱导抗性

Resistance Induced by Feeding Rhopalosiphum padi with 5 Aegilops Species

【目的】研究5种山羊草(Aegilops)对禾谷缢管蚜(Rhopalosiphum padi)取食的诱导性抗性机理,探索多酚氧化酶(PPO)、过氧化物酶(POD)与苯丙氨酸解氨酶(PAL)的诱导性抗性及协同抗蚜性,探索利用禾谷缢管蚜取食产生的叶片受害斑点面积进行抗性评价的可行性。【方法】利用薄层层析定量分析芦竹碱、紫外分光光度计测定PPO、POD、PAL酶活,用PHOTOSHOP7.0估算受害斑点面积等。【结果】不同抗性野生山羊草旗叶受害斑点面积大小具有一定的规律性且与蚜量比值呈极显著正相关(r=0.951**),与山羊草抗蚜性密切相关。在蚜虫取食诱导后,不同抗性水平的植株体内PPO、POD及PAL的酶活提高率随物种抗性水平的增加而增加,且与蚜量比值表现出一定的负相关;而与受害斑点面积表现出显著负相关,其多元逐步回归方程为Yarea=0.187-0.0356XPOD[F=17.0065,F0.05(1,3)=10.1,F0.01(1,3)=34.1];PPO酶活诱导性提高率与蚜量比值的相关有56.37%是由POD协同作用而产生的,反之则为46.85%。在蚜虫取食诱导后,山羊草芦竹碱的含量提高率与蚜量比值呈显著的负相关,相关系数分别为-0.884*。【结论】蚜虫取食危害产生的叶片受害斑点面积大小与小麦抗蚜性密切相关。PPO、POD、PAL酶活提高率与蚜虫取食诱导有关。PPO与POD在山羊草抗蚜性方面具有协同作用。芦竹碱对禾谷缢管蚜种群数量发展具有一定的抑制作用。

[Objective] The induced resistance, expressed with the activities of PPO, POD, and PAL, of 5 Aegilops species after feeding by Rhopalosiphum padi was studied and the method of evaluating resistance to aphid with necrosis area induced by aphid was explored. [Method] Content of gramine was determined by TLC, and enzyme activities of PPO, POD and PAL were measured by UV spectrophotometer, necrosis area induced by aphid was calculated by PHOTOSHOP 7.0. [Result] The necrosis area on leaves of these species which had different resistance levels were found to have a regularity and positively related to ratio of aphid number （r=-0.951＊＊） and were closely correlated to the level of resistance. After feeding by aphids, the increase rate of PPO, POD and PAL activities in different species with the increase of different levels of resistance of different species, and negatively related with the ratio of aphid number, and significantly negatively related to necrosis. The multinary stepwise regression equation is yarea=0. 187-0.0356XPOD[F=17.0065, F0.05 （1,3） =10.1, F0.01 （1,3） =34.1]. 56.37% correlation between the increase ratio of PPO activity and ratio of aphid number was synergied by POD. Conversely, 46.85% correlation happened to POD was produced by PPO. After aphid＇s feeding, the increase ratio of gramine were negatively related to ratio of aphid number significantly （r=-0.884＊）. [Conclusion] Close correlation was found between the necrosis area on the leaf damaged by aphid and the resistance of Aegilops to aphid. The increase ratio of PPO, POD and PAL activities are related to the induced resistance from aphid＇s feeding. PPO and POD were synergied each other in resistance of Aegilops to aphid. Gramine could prevent Rhopalosiphum padi. from growth to some degrees.