School of Biological Sciences, University of Bristol, Bristol, BS8 1TQ, UK.
The John Krebs Field Station, University of Oxford, Wytham, Oxford, OX2 8QJ, UK.
Planta. 2022 Mar 4;255(4):78. doi: 10.1007/s00425-022-03864-9.
Using petrolatum gel as an antitranspirant on the flowers of California poppy and giant bindweed, we show that transpiration provides a large contribution to floral humidity generation. Floral humidity, an area of elevated humidity in the headspace of flowers, is believed to be produced predominantly through a combination of evaporation of liquid nectar and transpirational water loss from the flower. However, the role of transpiration in floral humidity generation has not been directly tested and is largely inferred by continued humidity production when nectar is removed from flowers. We test whether transpiration contributes to the floral humidity generation of two species previously identified to produce elevated floral humidity, Calystegia silvatica and Eschscholzia californica. Floral humidity production of flowers that underwent an antitranspirant treatment, petrolatum gel which blocks transpiration from treated tissues, is compared to flowers that did not receive such treatments. Gel treatments reduced floral humidity production to approximately a third of that produced by untreated flowers in C. silvatica, and half of that in E. californica. This confirms the previously untested inferences that transpiration has a large contribution to floral humidity generation and that this contribution may vary between species.
我们使用凡士林凝胶作为加利福尼亚罂粟和巨型旋花的止汗剂，表明蒸腾作用对花朵湿度的产生有很大的贡献。花朵湿度是指花朵头部空间中湿度升高的区域，据信主要是通过蒸发液体花蜜和花朵蒸腾失水的组合产生的。然而，蒸腾作用在花朵湿度产生中的作用尚未得到直接测试，并且主要通过去除花蜜后持续产生湿度来推断。我们测试了蒸腾作用是否有助于先前确定产生升高的花朵湿度的两个物种 Calystegia silvatica 和 Eschscholzia californica 的花朵湿度产生。经过止汗剂处理（凡士林凝胶阻止处理组织的蒸腾作用）的花朵的花朵湿度产生与未接受此类处理的花朵进行了比较。在 C. silvatica 中，凝胶处理将花朵湿度产生降低到未处理花朵的三分之一左右，而在 E. californica 中则降低到一半。这证实了之前未经测试的推断，即蒸腾作用对花朵湿度的产生有很大的贡献，并且这种贡献可能因物种而异。
