连续多代UV B处理对麦长管蚜生态学的影响

为评估紫外线UV-B对麦长管蚜Sitobion avenae (Fabricius)生长、发育和繁殖的影响,用中波紫外线(UV-B)连续照射8代麦长管蚜3、4龄若虫,并用特定年龄生命表方法对其后代生态学参数进行分析.结果显示,麦长管蚜在实验室条件下多代饲养,表现出明显的种群退化现象.在UV-B的影响下,随着世代的增加,麦长管蚜的内禀增长率(Rm)、净增值率(R0)、周限增长率(λ)和种群数量趋势指数(I)均下降,到第3代出现最低值,后趋于稳定,而发育历期(T)呈递增趋势；UV-B处理后,F1～F5代麦长管蚜的2、3和4龄若虫发育历期延长,而到F7代差异不显著；成虫寿命、繁殖力(F)和种群数量趋势指数(T)均先减少后增加或趋于稳定,并且最小值基本都在第3代出现.这说明,UV-B对亲代麦长管蚜的影响可以传递到子代,产生累积作用,UV-B作为不利环境因子阻碍麦长管蚜的生长发育和繁殖,但随着处理代数的累加,增强麦长管蚜对胁迫的适应性.并且UV-B处理对麦长管蚜翅型变化影响显著.翅型的变化与麦长管蚜生态学参数变化有相关性.

Ecological Effects on the Aphid Sitobion avenae (Fabricius) Exposed to UV B Radiation for Several Successive Generations

The effects and changing patterns of UV-B on growth,development and reproduction of Sitobion avenae(Fabricius) were evaluated by establishing an age-specific life table of S.avenae exposed to UV-B for eight successive generations.The results revealed that the population degradation existed in the population of S.avenae after being raised for several generations in the experimental condition.Under the UV-B irradiation,the developmental duration(T) increased gradually with the increase of generations,while the intrinsic rate of increase(Rm),net reproductive rate(R0),finite increase rate(λ) and population number tendency index(I) of S.avenae decreased until the third generations,then stable in the following generations.The developmental duration of the second,the third and the fourth instar nymph from F1 to F5 of S.avenae were delayed,while no significant difference was found in F7 generation.Additionally,under the condition of UV-B,the adult longevity,fecundity(F) and population number tendency index(I) decreased until the F3 generation and then increased or trended to stabilize thereafter.In conclusion,the effects of UV-B would be accumulated in the progeny.As the selective forces in the environment,UV-B inhibited the growth and propagation of S.avenae,however,the adaptation of S.avenae to stress was enhanced with the increase of generations.We also found that,the transform of phenotype from unwinged to winged S.avenae was significant in this study,which was related with that of the ecology parameters.