VOA常速英语:Plant Siblings Less Competitive than Plant Strangers

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Plant siblings may be better at sharing than their human counterparts. That's one conclusion drawn from a new study that raises questions about the best way to grow crops.

Plants growing in close proximity have to compete for underground water and nutrients. So, to collect what they need to thrive, they usually put out lots of roots.

"That's a typical sign of plants under stress to compete," says Harsh Bais, a plant scientist at the University of Delaware. He says researchers recently made the surprising discovery that when neighboring plants come from the same mother they don't put out as many roots as they do when a stranger is growing beside them; even if that stranger is from the same species.

How do plants know when their neighbors are kin?

Bais and his colleagues discovered that the plant's roots produce a kind of chemical signal that helps them tell a sibling from a stranger.

While the discovery is interesting, it could have practical implications. Bais notes that energy spent on developing roots is energy that can't be spent on something else, for example on fighting disease.  

"If plants are actually allocating roots and they are doing much more than they are supposed to, are they more susceptible to infections at that point? We don't know," says Bais.

The idea that a field of siblings may be healthier goes against the conventional wisdom that genetic diversity is important for crop health. But Bais is looking into it. He says much is unknown about how plants interact with each other underground. But it seems that their sibling rivalries are a lot less fierce than their human counterparts.