牛角花齿蓟马为害对紫花苜蓿活性氧代谢的影响

Effect of Odontothrips loti on Reactive Oxygen Metabolism of Medicago sativa

以抗、感蓟马苜蓿无性系R-1、I-1为材料,测定了不同虫口密度下牛角花齿蓟马对紫花苜蓿活性氧(ROS)代谢的影响。结果表明:R-1无性系H2O2含量、OH·浓度和O2·-产生速率在低虫口密度(1、3头/枝条)下无明显变化,高虫口密度(5、7头/枝条)下明显上升。I-1无性系H2O2含量和O2·-产生速率均呈上升趋势,OH·浓度第1天上升,之后下降,第3天又呈上升趋势。二者的MDA含量均呈现上升,MDA增加量与虫口密度呈显著的正相关,且I-1显著高于R-1。相比之下,R-1能够及时清除体内的ROS使其保持在较低水平而表现为抗蓟马,而I-1的ROS代谢明显失调,其膜脂过氧化程度较R-1严重,因此表现为感蓟马。

The resistant and susceptible alfalfa clones R - 1 and I - 1 were empolyed to test effect of Odontothrips loti on reactive oxygen metabolism of Medicago sativa. Results showed that hydrogen peroxide （H202 ） content, hydroxyl radical （ OH ） concentrations and superoxide anion free radical （ 02 - ） generation rates of R - 1 had no obvious change under low thrips density （ 1, 3 per branch） , but increased during late damage stage under high thrips density （5,7 per branch）. And for I - lclones, H202 content and 02- generation rate tended to increase, while OH concentration increased firstly on the first day of damage, decreased on the second day and then increased again on the third day of damage. Malondialdehyde （MDA） content increased under different thrips density for both of R - 1 and I - 1 clones, and increment of MDA and population density had significant positive correlation. MDA increment of I - 1 were obviously higher than that of R - 1. So, R - 1 showed resistance on thrips because it had stronger capability in eliminating reactive oxygen species and keeping at a low level, while I - 1 belonged to susceptible variety due to an imbalanced reactive oxygen metabolism, and accompanied with a more severe lipid peroxidation.