时差N小时 你知道植物也有夜生活吗?(下)（在线收听）

Midway through the day, the biologists exposed the plants to a brief period of complete darkness.

生物学家在白天期间让植物暂时陷入完全的黑暗。

What effect did this have on flowering? Absolutely none.

这会对植物开花有什么影响吗？完全没有。

Next, for several nights, in the middle of the night, they exposed the plants to a brief period of light.

接下来，他们连续几个午夜让植物接受短暂的光照。

To the biologists’ surprise, this brief interruption of the darkness inhibited flowering.

令他们吃惊的是，这短暂的光照竟然阻碍了植物开花。

Clearly it was the long period of darkness and not the short period of light that caused flowering.

很明显，影响植物开花的是长时间的黑暗，而不是短暂的光照。

Although plants are sensitive to the nighttime part of the light-and-dark cycle, biologists and gardeners often still refer to plants as day length sensitive.

尽管植物对昼夜交替中的黑暗时段十分敏感，但是生物学家和园丁还是倾向于认为植物对昼长敏感。

For example, poinsettias are called “short-day” plants because they flower in winter.

比如，一品红被称为“短日照”植物是因为它在冬季绽放。

A stickler for accuracy might call poinsettias “long-night” plants, because what prompts their flowering isn’t the short days of winter, but the long nights.

一个严谨的人可能会将一品红称为“长夜”植物，因为促使它们开花的不是冬天的短暂白昼，而是冬天的漫漫长夜。