Effects Of Heat Stress On Trehalose Content And Trhalase Activity In The Insecticide-resistant And -susceptible Plutella Xylostella (L.)

In this study, the insecticide-susceptible(S) and resistant(R) strains of [Plutella xylostella (L.)7 which reared at high temperatures(33.5,35,37,40℃) lasting for different time(4,8,24,48,72h), were compared with the trehalose content and the trehalase activity in different age[larva(all of the larva in this paper is four ages,I will call larva for simple and not darm again),pupa,adult];and compared the spems DNA damage level of [Plutella xylostella (L.)] induced by high temperature (40 ℃) lasting for different time (24,48,72h),It is studied by single cell gel electrophoresis, to study the mechanism of [Plutella xylostella (L.)]populations reproductive development abilities on the high temperature further. And the results of this thesis showed that:(1) The trehalose content of [Plutella xylostella (L.)] larva under high temperatures (33.5,35,37,40℃) lasting for different time(4,8,24,48,72h), has show the lowered after the first, the high-temperature-treatment lasting for short period(4h) has made the trhalose content of [Plutella xylostella (L.)] larva have a shout increase, but the overall has declined as the processing time extended, however, it will rebound after 72h; at the same treatment, trehalase activity in [Plutella xylostella (L.)] larva could be reduced; the trehalose content and trehalase activity in R strains of [Plutella xylostella (L.)] larva was lower than S, and the drop of R [Plutella xylostella (L.)J by high temperature is significantly higher than sensitive [Plutella xylostella (L.)];(2) The trehalose content and the activity of trehalase of [Plutella xylostella(L.)] pupa de-cline treated by different times(4,8,24,48 and72 h) at high temperatures (33.5, 35,37,40℃), but the level of inhibition is not significant. The degree of inhibition of r esistant [Plutellaxylostella(L.)]is more significant than that of sensitive strain, and the r esult at 33.5 ℃was apparent specially. The degrees of inhibition of [Plutella xylostell (L.)]pupa between resistant and sensitive strains have no significant difference.(3)The trehalose content and the activity of trehalase of [Plutella xylostella(L.)] adults dr-opped dramatically treated by different time(4,8,24,48,72 h) at high temperatur es (33.5,35,37,40 ℃).The degree of inhibition of sensitive [Plutella xylostella(L.)] is more higher than that of resistant strain. The inhibition rates of trehalose and the acti vity of trehalase of [Plutellxylostella(L.)]adults reaches the peak at the age of 3rd-insta r. The inhibition of trehalase activity is especially far higher than the first two instars.(4)The [Plutella xylostella (L.)] adult has reared at high temperatures (33.5,35,37.40℃)lasting for different time(4,8,24,48,72 h), the sperm DNA damage is increased as the extension of treatment time, The comet rate and fluorescence intensity, length, area of comet tails are increasing as high temperature and longer time, it proves that the frequency of sperm DNA damage and damage degree have more while high temperature and processing time are rising.