NS-83对桃蚜传播芜菁花叶病毒(TuMV)的作用

EFFECTS OF NS-83 ON THE TRANSMISSION OF TURNIP MOSAIC VIRUS(TuMV)BY PEACH APHID(MYZUS PERSICAE)

1%NS—83乳剂喷布饲毒毒源芥菜(Brassica juncea)病株与检测植物油青菜(Brassica chinensis)植株,桃蚜传播TuMV受到了显著抑制,抑制效果为39.0%左右,但用乳化剂处理的植株未表现抑制作用。NS—83的抑制效果随使用乳剂中NS—83浓度升高而增加,随接种压力(每株传毒蚜虫数)增大而降低。桃蚜在传毒前、饲毒时和传毒时口针接触NS—83后,传播TuMV分别受到了41.8,29.4和14.1%的抑制。NS—83以不同方式处理饲毒株与传毒株,抑制效果不同,结果表明NS—83在TuMV一桃蚜复合关系中起作用。用1%NS—83乳剂涂抹芥菜叶片6、12、24、48小时后,桃蚜在上面的探食(试探取食)行为发生了显著的改变,表现在所观察的探食时间的缩短及两次探食间爬行时间的延长。

In the green house tests, the transmission of TuMV by the apterous peach aphids was inhibited by the virus-resistance inducer NS-83(1% water emulsion), but not by the emulsifier alone.The inhibitory effect of NS-83 was increased with the increment of the concentration of NS-83 in water emulsion used for spraying plants and with the decrease of inoculum stress, namely the number of aphids per plant. 1% NS-83 water emulsion inhibited the aphid transmission of TuMV to the extent of 41.8%, 29.4% and 14.1% when the stylets of the aphids were allowed to contact with NS-83 preparation before acquisition, during acquisition and during inoculation respectively. However there was no noticeable effect on transmission of the virus when the plants were sprayed with this preparation about 24 hr after inoculation, A definite influence of the applied preparation on the feeding behaviour of the apterous Myzus persicae was observed. Results showed that when the apterous peach aphids were laid on the surface of the NS-83 treated leaves, the gap time between access of aphids to the part for feeding and start of the first probe became longer.It is also true for the length of gap between the first probe to the second probe. However, the duration both for the first and second probe are rather shorter.It is therefore of the opinion that the effect of NS-83 on the aphid transmission of TuMV is quite different from those so far reported for oil emulsions.