不同苜蓿品种对苜蓿斑蚜的抗性

An evaluation on resistance of spotted alfalfa aphid to different Medicago sativa cultivars

苜蓿斑蚜(Therioaphis trifolii)是苜蓿(Medicago sativa)的重要害虫,在全国苜蓿主产区危害严重。本研究通过研究苜蓿斑蚜在不同苜蓿品种苗期的取食行为过程、蚜虫胁迫下苜蓿生物量变化,进而分析不同品种上蚜虫数量种群动态。结果表明:苜蓿斑蚜C波和E1波在甘农4号苜蓿上总持续时间最长,分别为179.52和27.24 min;E2波总持续时间为29.49 min,显著低于其他4个品种(P<0.05)。其中,金皇后和皇冠E1波的总持续时间显著低于其他品种(P<0.05),而E2波的总持续时间显著高于其他品种(P<0.05);中苜3号和MF4020的昆虫刺探电位仪(electronic penetration graph)和EPG指标均无显著差异(P>0.05)。EPG技术与蚜量比值法评估不同苜蓿品种对蚜虫抗性水平的结果一致,抗性水平由大到小为甘农4号>中苜3号>MF4020>金皇后>皇冠;生物量测定也表明甘农4号和中苜3号是抗性较高的品种,适合作为宁夏地区苜蓿抗蚜品种大面积推广。

Theriaphis trifolii is a crucial pest in alfalfa field,which causes serious harm to alfalfa production in most areas in China.In our study,the feeding behavior of aphid were screened at the alfalfa seedling stage.The change of alfalfa biomass under aphid stress were estimated and the population dynamics of aphids was also assessed on different alfalfa cultivars.The results showed that the total duration of C wave and E1 wave on Gannong No.4 was the longest,being 179.52 and 27.24 min,respectively.The total duration of E2 wave was 29.49 min and it was significantly lower than that on the other four cultivars(P<0.05).The E1 wave of the aphid in the Golden Empress and the Crown was significantly shorter than that on other cultivars(P<0.05),while the total duration of E2 wave was significantly higher than that on other cultivars(P<0.05).There was no significant difference in EPG(electronic penetration graph)between Zhongmu No.3 and MF4020(P>0.05).EPG technique on the alfalfa susceptibility to spotted alfalfa aphid were coincided with the approch of aphid abundance.The resistance level of alfalfa to aphid was ranked as the following:Gannong No.4>Zhongmu No.3>MF4020>Golden Empress>Crown.The estimation of alfalfa biomass also indicated that Gannong No.4 and Zhongmu No.3 were both resistant cultivars which are suitable for extension in Ningxia practically.