不同波长光照对草地贪夜蛾成虫趋光行为及视蛋白表达量的影响

Effects of different wavelengths of light on the phototactic behavior and opsin expression in Spodoptera frugiperda adults

为提高诱虫灯对草地贪夜蛾Spodoptera frugiperda的诱集效果,在室内测试了草地贪夜蛾雌雄成虫对390~550 nm 10种不同波长光源的趋光行为反应,以及光刺激对其4种视蛋白基因表达量的影响。结果表明:草地贪夜蛾雌蛾和雄蛾对10种波长光源的趋光率均存在显著差异,其中雌蛾对绿光区510、520 nm和550 nm的趋性较高,趋光率分别为68.5%、65.0%、63.5%;雄蛾对绿光区520 nm及紫光区420 nm的趋性较高,趋光率分别为69.0%和60.5%。雌雄成虫对510 nm和550 nm的趋光率存在显著的性别间差异,但其他供试波长处理下,雌雄成虫的趋光率均无显著的性别间差异。520 nm光源刺激下,雌蛾和雄蛾均表现为3日龄(雌:65.0%;雄:69.0%)和5日龄(雌:59.1%;雄:61.4%)的趋光率最高,而1日龄(雌:41.4%;雄:24.1%)的趋光率最低。雄蛾受520 nm光刺激20 min后,其紫外光敏感蛋白(UV-opsin)基因的相对表达量显著升高,是对照组的3.61倍;但长波敏感蛋白1(LW-opsin1)、长波敏感蛋白2(LW-opsin2)和蓝光敏感蛋白(B-opsin)基因的相对表达量与对照组相比无显著差异。雌蛾受520 nm光刺激20 min后,其4种视蛋白基因的相对表达量与对照组相比均无显著差异。综上所述,草地贪夜蛾成虫对绿光和紫光较为敏感,羽化3~5 d的成虫趋光性最强,视蛋白基因表达量的改变可能是草地贪夜蛾成虫对光刺激产生行为反应的关键因素。

In order to improve the light-trapping efficacy on Spodoptera frugiperda in the field,the phototactic behavior of male and female moths to 10 light sources with different wavelengths(390-550 nm)and the effect of light stimulation on the expression levels of four opsin genes of S.frugiperda were tested in the laboratory.The results showed that there were significant differences in the phototactic rate of both male and female moths to 10 light sources.The female moths showed relatively higher phototaxis to 510 nm,520 nm and 550 nm(green light),with a phototactic rate of 68.5%,65.0%and 63.5%,respectively.The male moths showed relatively higher phototaxis to 520 nm(green light)and 420 nm(purple light),with a phototactic rate of 69.0%and 60.5%,respectively.For the 10 different light wavelengths tested,there were significant inter-sexual differences in the phototaxis of S.frugiperda moths to 510 nm and 550 nm,but no significant differences to the other wavelengths.The phototaxis of moths at different day-ages to the stimulation of 520 nm light was tested,and the results showed that both female and male moths had the highest phototactic rate at the age of 3 day-old(female:65.0%;male:69.0%)and 5-day old(female:59.1%;male:61.4%),while the lowest at the age of 1-day old(female:41.4%;male:24.1%).When male moths were stimulated by 520 nm light for 20 min,the relative expression level of ultraviolet-sensitive opsin(UV-opsin)gene increased significantly,which was 3.61 times of the control.However,the relative expression level of the other tested opsin genes had no significant difference from the control group,including the long-wavelength-sensitive opsin 1(LW-opsin1),the long-wavelength-sensitive opsin 2(LW-opsin2)and the blue-sensitive opsin(B-opsin)genes.When female moths were stimulated by 520 nm light for 20 min,the relative expression level of the four tested opsin genes had no significant differences from the control.In conclusion,S.frugiperda moths had higher sensitivity to green and purple lights,and the highest phototaxis occurred at the age of 3-day and 5-day old after emergence;meanwhile,the changes of expression level of opsin genes might be the key factor affecting the response of S.frugiperda to different light stimulations.