Differences in thermal regimes are of paramount importance in insect development. However, experiments that examine trait development under constant temperature conditions may yield less evolutionarily relevant results than those that take naturally occurring temperature fluctuations into account. We investigated the effect of different temperature regimes (constant 30 °C, constant 35 °C, fluctuating with a daily mean of 30 °C, or fluctuating with a daily mean of 35 °C) on sex-specific development time and body mass in Tribolium castaneum. Using a half-sib breeding design, we also examined whether there is any evidence for genotype-by-environment interactions (GEI) for the studied traits. In response to fluctuating temperature regimes, beetles demonstrated reaction norm patterns in which thermal fluctuations influenced traits negatively above the species’ thermal optimum but had little to no effect close to the thermal optimum. Estimated heritabilities of development time were in general low and non-significant. In case of body mass of pupae and adults, despite significant genetic variance, we did not find any GEI due to crossing of reaction norms, both between temperatures and between variability treatments. We have observed a weak tendency towards higher heritabilities of adult and pupa body mass in optimal fluctuating thermal conditions. Thus, we have not found any biasing effect of stable thermal conditions as compared to fluctuating temperatures on the breeding values of heritable body-size traits. Contrary to this we have observed a strong population-wide effect of thermal fluctuations, indicated by the significant temperature-fluctuations interaction in both adult and pupa mass.

中文翻译：

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发育和体重对每日温度波动的响应：bol藜的研究。

在昆虫发育过程中，热态的差异至关重要。但是，与在自然条件下考虑温度波动的情况相比，在恒温条件下检查性状发育的实验所产生的进化相关结果较少。我们研究了不同温度模式（恒定30°C，恒定35°C，每天平均波动30°C或每天平均波动35°C）对性别特定发育时间和体重的影响。bol藜。使用半同胞繁殖设计，我们还研究了所研究性状是否存在任何基因型-环境相互作用（GEI）的证据。响应温度变化的情况，甲虫表现出反应规范模式，在该模式中，热涨落对物种的热最适度产生负面影响，而接近热最适度则几乎没有影响。估计的发育时间遗传力一般较低且不显着。对于p和成年人的体重，尽管遗传差异很大，但由于温度和变异性处理之间反应规范的交叉，我们没有发现任何GEI。我们已经观察到，在最佳的波动热条件下，成年和body体重的遗传力呈弱趋势。从而，与温度波动对可遗传的体型性状的育种值相比，我们没有发现稳定的热条件有任何偏见。与此相反，我们观察到了热波动对整个人群的强烈影响，这在成年和质量中都存在着明显的温度-波动相互作用。