光周期对玉米蚜生长发育及种群参数的影响

为阐明光周期对玉米蚜生长发育及生命参数的影响,构建了不同光周期的玉米蚜种群生命表,将光周期分别设置为2L∶22D、4L∶20D、8L∶16D、12L∶12D、16L∶8D、20L∶4D、22L∶2D,测定不同光周期条件下玉米蚜的发育历期、生殖力、存活率、生殖期及各项生命参数。结果显示:光周期为20L∶4D和22L∶2D时玉米蚜的若虫期显著(P< 0.05)长于其他5个光周期,光周期为8L∶16D、12L∶12D、16L∶8D时玉米蚜的若虫存活率显著(P<0.05)高于光周期为4L∶20D、20L∶4D、22L∶2D的处理,光周期为8L∶16D、12L∶12D、16L∶8D时玉米蚜的生殖力显著(P<0.05)高于其他光周期处理,光周期为12L∶12D时的内禀增长率、净增殖率和周限增长率均最高(0.357、42.06和1.43),正常光周期(8L∶16D、12L∶12D、16L∶8D)的内禀增长率、净增殖率和周限增长率均显著(P< 0.05)高于2L∶22D、22L∶2D处理,光周期为2L∶22D的内禀增长率、净增殖率和周限增长率均最低,生命参数与光周期的拟合方程预测出玉米蚜的最适光照时间为11~13 h·d^-1。以上结果说明,极端光周期干扰了玉米蚜正常的生长发育,极端长光照或短光照均会影响玉米蚜种群动态的发展和变化。

Effect of photoperiods on growth and development and population parameter of corn leaf aphids

In order to clarify the effects of photoperiod on the growth and development of the corn leaf aphid Rhopalosiphum maidis, and to construct its life table under different photoperiods, aphids were reared with leaves in petri dishes under different photoperiods (2L∶22D, 4L∶20D, 8L∶16D, 12L∶12D, 16L∶8D, 20L∶4D, 22L∶2D), and their developmental time, fertility, survival rate and life parameters were measured. The results showed that the developmental time of immature under photoperiods of 20L∶4D and 22L∶2D were significantly longer than those under other five photoperiods (P<0.05).The survival rate of corn leaf aphid under 8L∶16D, 12L∶12D, 16L∶8D were significantly higher than those under photoperiods of 4L∶20D, 20L∶4D, 22L∶2D (P<0.05). The fertility under photoperiods of 8L∶16D, 12L∶12D, 16L∶8D were significantly higher than other photoperiods (P<0.05). The intrinsic rate of increase (r_m), net reproductive rate (R₀) and finite rate of increase (λ) under photoperiod of 12L∶12D were the highest (0.357, 42.06 and 1.43 respectively). The r_m, R₀ and λ under normal photoperiods of 8L∶16D, 12L∶12D and 16L∶8D were significantly higher than extreme photoperiods of 2L∶22D, 22L∶2D (P<0.05). The r_m, R₀ and λ under photoperiod of 2L∶22D were the lowest. The optimal photoperiods calculated with the fitting equation of life parameter and photoperiods was 11-13 h·d^-1. Above results indicated that the normal growth and development of corn leaf aphid under extreme photoperiods were interfered, extremely long or short photophase period would affect the development and dynamic changes of this population.