Rice, taking a great portion of human’s food, especially for those who live in Asian area. Its grains are delivered to the table as the main food, but where had the stem gone after harvest?
Some of the stem may be turned over to field through straw incorporation which is one of the best methods to increase soil fertility. Others may be made into ensilage, an important kind of animal feed, after a period of microbial fermentation.
No matter, where the stem will go, they all need to be cut and smashed. However, it is not easy for rice stem is ductile.
What if rice stem become much more brittle? If so, the rice harvest would be much easier and more energy-saving as well. However, every coin has two sides. The risk of beating down will greatly increase with the stem becoming more brittle.
An over-ten-year work by Hefei Institutes of Physical Science (HFIPS) researchers brings us a new rice which has brittle stem but will not be beat down by even strong wind.
Let us have a back-look on how they started their work. Actually, most of the components in rice can be regulated by genetic genes. That was why the team started their work at genetic molecular study on the mechanism of brittle stem mutant in rice.
They began their work at the ion beam breeding in which they exposed the seeds to heavy ion bean irradiation. Then the team found twenty-two different brittle stem mutants among which four new mutants were cloned and analyzed on gene function. Then they identified the most ideal one.
The best candidate, called brittle stem mutant Ideal Brittle Culm (IBC), was expressed in a certain time that only after bloom would the rice stem become brittle, which would reduce the risk of beating down during its growing season. And even more exciting, IBC was expressed only in some specific areas, like stem. As for other parts, like leaves, they are not included.
Based on the previous breeding and picking-up work, the team started the hybridization then a new rice was made. They called the new “baby”, Kefujing 1, which, in Chinese, means a kind of rice that was produced by scientific irradiation.
Kefujing1, as the team expected, had a much more brittle stem, making it much easier to be cut and smashed.
But, to what extend could the stem of Kefujing 1 withstand strong wind? A series of wind tunnel tests were conducted. The team was happy to see that Kefujing 1 had passed the wind tests. It stood even in a strong wind as high as nine gale.
Besides, component tests showed Kefujing 1 could be a good kind of stem for animal feeding as there were a decrease by 11.9% and 16.6% in cellulose and xylogen, respectively and an increase by 15.7% in hemicellulose. All of these parameters demonstrated clearly a dramatic improvement in nutrition of the stem.
Now, the team is planning to build a recycle operation by providing technology all through the full industry chain from seed breeding to rice stem-based animal feeding.