Study On Relative Fitness And Resistant Inheritance Mode For R-fenpropathrin And R-spirodiclofen Populations Of Tetranychus Urticae Koch

This article through indoor resistant selection for Tetranychus urticae to fenpropathrin and spirodiclofen, studying on biological characteristics,relative fitness and resistant inheritance mode of resistant populations under different temperature provided the reliable theory basis for pesticides scientificly and reasonably used and the comprehensive governance of the resistance and got the following main research results:1.Study on the biological characteristics of resistance- fenpropathrin (R-fen) and resistance-spirodiclofen (R-spi) populations under different temperature The state developmental time,female sex ratio,female life and fecundity of R-fen,R-spi and sensitive population (S) of T.urticae were studied on the effect of the temperature in conditions with17℃,20℃,25℃,28℃,32℃,36℃six temperature gradients, illumination of 14h, relative humidity(70±5)%. The results indicated that each T.urticae population's state developmental time, whole generation time and female life were shorten with the temperature risen;And the female sex ratio with temperature changed but not present regularity, and had nothing to do with resistance; There was a relationship rose at first and then decreased between each population of fecundity and temperature, and in 28℃reached the maximum value when a fecundity: S﹥R-spi﹥R-fen.2.Study on the relative fitness of R-fen and R-spi populations under different temperatureConstructing resistance and sensitive experimental population life tables under different temperature analysed the temperature on the effects of experimental population parameters. The results showed that the relations were a second-degree parabola for the net reproductive rate (R0), the intrinsic growth rate (rm), the finite increase rate (λ) with the temperature, respectively,and population double time (t) and temperature were tending to pour parabola relation, while the mean generation time (T) and temperature in a linear relationship.T.urticae population growth exsisted a low and high temperature inhibition phenomenon. With the net reproductive rate (R0) to determine the relative fitness of two resistant populations (R-fen and R-spi),the results indicated that the relative fitness of resistant populations were less than 1 under different temperature, and existed different degree of biological fitness defects.Among them in low temperature (17℃) or high temperature (36℃), the relative fitness of two resistant populations were closed to 1, namely the adaptation of low and high temperature was consistent between T.urticae resistant and sensitive populations.3.Study on the resistant inheritance mode of R-fen and R-spi populations Under 28℃the cross breeding and back cross to T.urticae resistant population with sensitive population of parental and filial generations concluded that the resistant inheritance mode of T.urticae to fenpropathrin was monogentic and non-complete dominant in autosomal,and its cross F1 hybrids dominant degrees D were 0.4325 and 0.4379,respectively;While the resistant inheritance mode of T.urticae to spirodiclofen was polygentic and non-complete dominant in autosomal, and its cross F1 hybrids dominant degrees D were 0.3515 and 0.3401,respectively.