SSS 2009-11-20（在线收听）

We humans are known to help out members of our own families. When it comes to business we call it nepotism. Now plants have demonstrated the same predilection, in a study published in the American Journal of Botany.

Previous research showed that plants—in that study they used a plant called the Great Lakes sea rocket—can recognize the root systems of siblings from the same momma plant and will give them a more fair share of nutrients in the soil.

This new study is the first to look above ground. Researchers at McMaster University in Canada potted North American impatiens. When the plants shared a pot with seeds from the same parent plant, they shared access to light by growing taller with more branches and fewer leaves. But when those same impatiens were planted with other impatiens—but not their siblings—they put more energy into growing more and larger leaves that could crowd out the non-relatives.

Researchers say the roots alert plants to the relationship of nearby plants, because when impatiens were planted near siblings but in separate pots, they didn’t recognize their kin. Just goes to show that even in the plant world, family comes first.