Abstract: The physiological indices,e.g.leaf relative water content(LRWC),chlorophyll content(CC),the activities of SOD and POD,and the contents of MDA and praline,of the endophyte-infected(E+) and endophyte-free(E-) drunken horse grass(Achnatherum inebrians(Hance) Keng) seedlings inoculated by oat-bird cherry aphid(Rhopalosiphum padi(L.)) were measured under different pest densities and different feeding periods.The results show that LRWC and CC were decreased significantly(P<0.05) by the aphid feeding in comparison with the control,the difference between E+ and E-were significant(P<0.05).The activities of SOD and POD were increased significantly(P<0.05) with the feeding periods and aphid densities,respectively,and significant(P<0.05) difference existed between E+ and E-only under 20 aphids/plant for 4 days.The contents of MDA and proline were increased significantly(P<0.05) by the inoculation of aphid for a given period and the difference between E+ and E-were significant(P<0.05).In summary,the grass endophyte could affect the feeding behavior of R.padi to a certain extent and further the physiological responses of the drunken horse grass.

Key words: Drunken horse grass, Oat-bird cherry aphid, Neotyphodium endophyte, Chlorophyll, Protective enzyme, Proline

摘要： 通过测定一系列生理变化指标,研究人工接种条件下禾谷缢管蚜(Rhopalosiphumpadi (L.))对带内生真菌(E+)与不带菌(E-)醉马草(Achnatherum inebrians (Hance) Keng)幼苗的影响.结果表明:在一定时期内,禾谷缢管蚜刺吸可使醉马草幼苗叶片相对含水量和叶绿素含量显著降低(P<0.05),同一个虫口密度E+与E-植株之间差异显著(P<0.05);幼苗体内SOD活性和POD活性均随危害时间的延长而显著升高(P<0.05),同一个虫口密度E+与E-植株之间差异显著(P<0.05);接种蚜虫可使MDA和游离脯氨酸的含量显著提高(P<0.05),同一个虫口密度内E+与E-植株之间差异显著(P<0.05).综上所述,内生真菌的侵染可以在一定程度上间接影响禾谷缢管蚜取食,进而影响醉马草幼苗生理生化的变化.

关键词: 醉马草, 禾谷缢管蚜, 内生真菌, 叶绿素, 保护酶, 脯氨酸