Matsuda Naoki, Kanbe Takashi, Akimoto Shin-Ichi, Numata Hideharu
Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502, Japan.
Graduate School of Agriculture, Hokkaido University, Sapporo, Hokkaido 060-8589, Japan.
J Insect Physiol. 2017 Aug;101:1-6. doi: 10.1016/j.jinsphys.2017.06.008. Epub 2017 Jun 10.
Many aphid species switch reproductive modes seasonally, with the sexual generations appearing in autumn. Sexual generations are induced by short days. It has been reported that the appearance of sexual morphs is suppressed by a transgenerational factor (a seasonal timer) over several generations after hatching from overwintered eggs. The present study examined whether the seasonal timer measures the number of days from hatching or the number of generations from hatching using the pea aphid, Acyrthosiphon pisum Harris (Homoptera: Aphididae). Effects of temperature and photoperiod on the seasonal timer were also examined by successive rearing. The ability to produce sexual morphs was strongly suppressed in stem mothers (the foundress generation), and gradually recovered over successive generations produced during a few months. The duration for which the seasonal timer could function depended on the number of days from hatching and temperature, but not on photoperiod or the number of generations from hatching. We thus showed in a single study that the seasonal timer of the pea aphid has all the physiological characteristics shown in separate studies in different aphid species.
许多蚜虫种类会季节性地转换繁殖模式，有性世代在秋季出现。有性世代是由短日照诱导产生的。据报道，从越冬卵孵化后的几代中，有性形态的出现受到一种跨代因素（季节性定时器）的抑制。本研究利用豌豆蚜（Acyrthosiphon pisum Harris，同翅目：蚜科），研究了季节性定时器测量的是孵化后的天数还是孵化后的代数。还通过连续饲养研究了温度和光周期对季节性定时器的影响。有性形态的产生能力在茎母（奠基者世代）中受到强烈抑制，并在几个月内连续产生的几代中逐渐恢复。季节性定时器能够发挥作用的持续时间取决于孵化后的天数和温度，而不取决于光周期或孵化后的代数。因此，我们在一项研究中表明，豌豆蚜的季节性定时器具有在不同蚜虫种类的单独研究中所显示的所有生理特征。
