快猫短视频

A DEVICE that sorts seeds according to their ability to germinate could save
farmers around the world millions of dollars. It does so by using a surprising
marker to measure their ripeness: the seed鈥檚 chlorophyll content.

Raoul Bino, head of reproduction technology at the Centre for Plant Breeding
and Reproduction Research in Wageningen, the Netherlands, says his team was
measuring the chlorophyll content of leaves when it made an accidental
discovery. 鈥淥ut of curiosity, we examined an old sample of cabbage seeds, which
are brown. To our amazement, we found measurable quantities of chlorophyll in
some seeds. We did not expect that at all.鈥�

Bino鈥檚 team is unsure what the chlorophyll does in the seed鈥攂ut it is
clear that it is not engaged in photosynthesis. 鈥淚f you shine light on the
chlorophyll in a seed, it does not transfer this energy to another molecule but
instead re-emits it at another wavelength鈥攎eaning that it fluoresces,鈥�
says Bino. 鈥淭his fluorescence can be measured. It is very simple. We are still
astonished that no one before us ever discovered it, and then used it to sort
蝉别别诲蝉.鈥�

Bino has discovered that seeds retain their chlorophyll for many years, so
long as they are kept dry. When they are moistened, the chlorophyll begins to
break down: 鈥淩eadiness to germinate and loss of chlorophyll go hand in hand,鈥�
says Bino, 鈥渢he less chlorophyll, the riper the seed.鈥�

To measure the chlorophyll content, the Dutch researchers illuminate the
seeds with red laser light, and measure the strength of the slightly
longer-wavelength light that the chlorophyll re-emits. By identifying the
optimal chlorophyll levels for ripeness, they have devised a reliable seed
sorting method.

The discovery is being commercialised by Satake USA, a company based in
Houston, Texas.