Hybrid rice facts for kids

Hybrid rice is a special kind of rice that's made by mixing two very different types of parent rice plants. Like other hybrids, hybrid rice often shows something called "hybrid vigor". This means it grows stronger and produces much more grain. In fact, it can yield up to 30% more rice than regular rice types grown in the same way!

To make lots of hybrid seeds, scientists take a special rice plant that can't produce its own pollen (it's "male sterile"). They then fertilize it with pollen from a different, fertile rice plant. Crops that produce a lot, like hybrid rice, are super important. They help fight against food shortages around the world.

The Story of Hybrid Rice

People have been mixing different rice types for a long time to create new ones, like the famous IR8 variety. Using "hybrid vigor" in the first generation of mixed seeds (called F1 seeds) was known. However, these F1 seeds were usually only made in small amounts.

In 1926, the first scientific paper about using hybrid vigor for rice was published. But it was hard to use this idea widely because rice plants usually pollinate themselves.

A big breakthrough happened in 1974. Chinese scientists successfully moved a special gene from wild rice into regular rice. This gene made the rice plant "male sterile" (unable to produce its own pollen). This allowed them to create a special genetic line called CMS (cytoplasmic male sterility). For the first time, F1 hybrid seeds could be used for planting on a very large scale. The first hybrid rice types produced about 15% to 20% more rice than other improved varieties.

The "Father of Hybrid Rice"

A Chinese scientist named Yuan Longping (1930–2021) is known as the "Father of Hybrid Rice". He is the most famous researcher in this field. In the 1960s, he made an amazing discovery about how hybrid vigor works in rice. This was unique because many thought it wasn't possible for crops like rice that pollinate themselves. In 2011, Yuan developed a new hybrid rice that could produce 13.9 tonnes of rice per hectare (a hectare is about 2.5 acres).

Another Chinese expert, Li Zhengyou, developed a type of hybrid rice called Dian-type. He was also a leader in growing hybrid rice in high-altitude areas. He even wrote a book about it!

Where Hybrid Rice is Grown

In China, more than half of all rice fields grow hybrid rice. This has helped China greatly increase its rice harvests, which are some of the biggest in Asia. Hybrid rice is also grown in many other countries that produce a lot of rice. These include Indonesia, Vietnam, Myanmar, Bangladesh, India, Sri Lanka, the Philippines, Brazil, and the USA. A study in 2010 found that growing hybrid rice in India could be up to 34% more profitable than other rice types.

Outside of China, other groups are also researching hybrid rice. One important group is the International Rice Research Institute (IRRI). They also help coordinate the Hybrid Rice Development Consortium.

Benefits and Challenges of Hybrid Rice

How Hybrid Rice Grows Better

Hybrid vigor shows up early in the plant's life. Young hybrid rice plants grow their roots and leafs faster. They also develop a better canopy (the leafy part of the plant). As they mature, they produce more plant material, larger panicles (the parts that hold the grains), and more spikelets (flower units) per area. This all leads to a heavier total weight of grains and, finally, higher yields.

Why Farmers Buy New Seeds Each Year

One challenge with hybrid rice is that farmers need to buy new seeds every season. Regular rice varieties produce seeds that are almost exactly like their parents. So, farmers can save these seeds and plant them later.

But if a farmer tries to plant seeds saved from a hybrid rice crop, the new plants will be very different from each other. It's like how siblings in a family look different. This means the next harvest won't be as good or as consistent.

Challenges with Diseases and Pests

In China, some features of the hybrid system have made it hard for researchers to find ways to improve the plants' resistance against diseases and pests. Hybrid rice can sometimes get more problems from pests like stem borers, whitebacked planthoppers, and leaf rollers. They can also get more diseases like bacterial blight, sheath blight, and viral diseases. This means that farmers often need to use more pesticides on hybrid rice. For example, in one area of China, 31% more pesticide was used on hybrid rice compared to regular crops.

Other Difficulties

The process of creating hybrid rice seeds is also expensive and takes a lot of time. This can be a challenge for private seed companies. For example, Cargill bought hybrid rice seeds from the Chinese government in the 1980s, but stopped selling them commercially by 1992.

Other challenges include:

• The quality of the grain might not always be as good.
• The first generation of hybrids might not have enough resistance to diseases and insects.
• Producing hybrid seeds can be inconsistent and yield low amounts.
• Getting enough pure parent seeds can be difficult.
• The seeds themselves can be expensive.

Also, the International Rice Research Institute (IRRI) shares its technology freely. While this is good in many ways, some believe it has slowed down research by making it harder for companies to profit from new discoveries.

Economic and Political Issues

Hybrid rice also brings up some economic and political concerns. Farmers lose their right to save their own seeds because hybrid seeds don't produce the same good crop after the first harvest. This means farmers have to rely on special seed companies. A few large seed companies control most of the hybrid rice seeds in a country. This could potentially lead to problems with food safety if something goes wrong.

What's Next for Hybrid Rice?

For the future, scientists want to make hybrid rice even better. They aim to improve the grain quality and make the plants stronger against pests and diseases. They also want to improve how well the parent plants produce hybrid seeds. More research is needed to develop hybrids that can yield even more than current high-yielding varieties.

Seed companies are encouraged to invest more in research to find the best ways to produce seeds and reach the market. Governments can also help by creating policies or providing money to support hybrid rice research.

Latest Discoveries

From October 21 to 22, 2019, a new type of hybrid rice was tested for the first time. This was the "third-generation hybrid rice." It was tested in Qingzhu Village, Hengnan County, Hengyang, Hunan Province, China. The yield was very impressive: 1046.3 kg per mu (which is about 15 tonnes per hectare).

This third-generation hybrid rice uses a genetically engineered sterile male line as a special tool. This technology allows almost any rice plant to find a perfect "match" to create excellent offspring.