Is rice inherently present in nature?

Yes, primitive humans came into contact with rice by chance.

Slash-and-burn farming began.

After genetic optimization, yield increases, and modern large-scale cultivation took place.

It was formed by the crossing of dog's tail grass and knotweed, and the original rice produced only one rice.

Also: There is a detailed explanation in the 4th or 5th issue of Science World.

Rice is a cross breeding of a variety of wild grasses.

Yes, later it was grown by itself, and at first it was wild.

That's of course. At first it was wild, then it was cultivated by humans.

From a wild rice domesticated by humans to today's rice.

Common wild rice is a close relative ancestor of cultivated rice. Common wild rice has evolved over the years to become modern cultivated rice. But in the process of evolution, many of the good genes of common wild rice have been lost.

A recent joint comparative study by China Agricultural University shows that modern cultivated rice has lost about 1 3 alleles and half of its genotypes compared with ordinary wild rice, including a large number of excellent genes, including disease resistance, insects, weeds and stress resistance genes, as well as high-efficiency nutrition genes and high-yield and high-quality genes.

Cultivated rice is generally annual, while common wild rice is a perennial herbaceous plant. The pollen of cultivated rice and ordinary wild rice generally has stamens and pistils at the same time, and the pollen abortion found by Yuan Longping refers to the pollen with intact pistils and aborted stamens. Yuan Longping used the pistils of this common wild rice as the female parent, and then used the stamens of cultivated rice as the male parent for crossing, so that the hybrid rice can have the genes of both wild rice and cultivated rice.

The hybrid rice bred by Yuan Longping happened to inherit the high-yield and high-quality genes of ordinary wild rice.

China is recognized as one of the centers of origin of cultivated rice in the world. Archaeological data from Yuyao, Hemudu and other places in Zhejiang Province show that our ancestors learned to cultivate rice as early as 7,000 years ago. As you can imagine, they observed that natural grain germination and growth were observed in the process of collecting wild rice for food, so they tried to sow wild rice, and repeated the process of harvesting and sowing, taking the first step towards planting rice.

After a long period of time, people's cultivation and cultivation of rice technology has become more and more sophisticated, and finally rice has become the main food on the table of Chinese. At the same time, the wild rice varieties that gave birth to cultivated rice also grow silently in the ponds, swamps and hillsides of southern China year after year until today.

<> the cultivation technique of this crop.

The crop likes high temperature, humidity and short daylight, and has low requirements for soil.

The south of China is the main producing area, and the northern provinces are cultivated.

1. Seed treatment.

Seed treatment is a prerequisite in planting technology, generally before planting, the selected seeds are cleaned and disinfected in potassium permanganate solution, and then placed in a mesh bag for germination treatment, and the temperature can be maintained at about 30 to germinate quickly.

2. Land preparation treatment.

In order to ensure the fertility of the cultivation medium, it is generally necessary to combine the cultivation and weeding treatment when preparing the land, and then add an appropriate amount of organic fertilizer and superphosphate, potassium sulfate and other fertilizer-sensitive residual materials to the soil, mix and stir evenly, and then add a small amount of Dixone for sterilization.

3. Transplanting treatment.

The germinated seedlings are transplanted into the soil, do not cultivate too densely, keep the plant row spacing at about 10 cm, hold the seedling roots by hand, insert the root system into the soil, it is best not to be too shallow, the root system should be kept completely covered by the soil, and it can also be carried out with a seedling machine, which is faster.

4. Post-planting treatment.

If there is a lack of seedlings after planting, it is necessary to replenish the seedlings in time to ensure the original planting density, and frequent irrigation treatment is required during the growth period, and the water can be increased during the seedling period, generally only need to be submerged to one-third of the plant bridge roll, and then add ammonium sulfate fertilizer appropriately according to the growth situation.

5. Weeding treatment.

After planting, it is best to carry out weeding treatment frequently, one week after planting, herbicides can be applied to it, mainly oxachlorone, and when the growth is better, benzylthioyl herbicides can be added to the fertilizer to mix and spray to avoid weeds affecting the normal growth of plants.

China has a long history of rice cultivation, and in ancient books such as "Guanzi" and "Lu Jia Xinyu", they were all sown in the Shennong period in the 27th century BC"Grains"According to the record, rice is listed as one of the five grains.

Historical Records Xia Benji" about"Yu Ling benefits the rice, can be planted damp"shows that in the 21st century BC, the Chinese people had already begun to fight against nature and relieve governance"Nine Rivers", utilization"Humble and wet"zone for the development of rice. About 4,200 years ago, rice cultivation was promoted from the middle and lower reaches of the Yangtze River to the middle reaches of the Yellow River.

In the Western Han Dynasty, terraced fields first appeared in Sichuan. In the 30s of the 6th century, Jia Sixian's "Qi Min Yaoshu" of the Northern Wei Dynasty once described the cultivation technology of rice and upland rice. In the Jin "Guangzhi", there is a record of developing green manure in rice fields, increasing the source of organic fertilizer, and cultivating soil fertility.

After the Wei, Jin, Southern and Northern Dynasties, China's economic center of gravity gradually shifted southward, and during the Tang and Song dynasties, Jiangnan became the center of rice production in the country, and the Taihu Lake basin was the rice production base. At that time, due to the emphasis on water conservancy construction, reclamation of rivers, lakes and tidal flats, improvement of agricultural tools, soil fertilization, double cropping of rice and wheat and renewal of varieties, etc., a relatively complete spellwork cultivation system had been initially formed in the Jiangling Zhunan rice area.

Current location: Rice is not a perennial plant. It is an annual plant that generally only lives for one year and has a relatively short lifespan. After planting in the first year, it can continue to grow in the second year, so it is best to plant it once a year.

In this case, the yield is also high, so it is more suitable for growing rice every year.

Is rice a perennial plant.

Rice belongs to the family Poaceae. It usually blooms in the spring, but ground-grown rice can leave it unflowered every year. Because the lifespan of rice is only one year, it needs to be replanted once in the second year.

The color of the flowers is golden. Current location: Rice is neither herbaceous nor woody. It is a special herbaceous plant and cash crop, which has high economic value and is the main food of the people of Tongjianqing**.

What kind of plant does rice belong to?

Rice is not a perennial plant and is usually an annual plant, and rice does not have bulbs. It has seeds and is usually sown in March-April each year.

What can be planted in a field where rice is planted in addition to rice?

When planting rice, the same brother can implement the comprehensive planting and breeding of rice and fishery, and release fish, shrimp, crab, snails, etc. In addition to planting rice, paddy fields can also be used to raise fish, shrimp, crabs, snails, etc. Rice is planted in the rice field, and at the same time, it can be raised for fish and ducks.

In addition to planting rice, the current rice fields can also raise fish, ducks, snails, etc.

The fundamental difference between early, middle and late rice is the difference in response to light. Early, middle rice is not sensitive to light response, and can mature normally in all seasons of the year, while late rice is very sensitive to short daylight, and it is strictly required to pass the light stage and set heading under short day conditions. Late rice is very similar to wild rice, which is the basic type formed by the direct evolution of wild rice, and early and middle rice are variants formed by the differentiation of late rice under different temperature and light conditions.

The rice in the northern rice region belongs to early or medium rice.

Rice and upland rice are grown in paddy fields, and upland rice is grown in dry land. The morphological differences of water and land rice were small, and the physiological differences were large. Both water and terrestrial rice have aerated tissues, but the seeds of upland rice need less dumplings when germinating, and the water absorption is strong, and the germination is faster. The stems and leaves of terrestrial rice have well-developed protective tissues and strong heat resistance. The root system is well developed, the root hairs are abundant, and the adaptability to water reduction is strong.

Land rice can be dry seed, can also be water seed, some varieties can be used for both land rice and rice cultivation, but the yield of land rice is generally low, land rice is gradually replaced by rice, only a small amount of land rice cultivation in the northern rice area.

In addition, in the taxonomy of rice, according to the cultivation method of rice and the amount of water required during the growth period, there is a distinction between rice and upland rice. Upland rice, also known as upland rice, is planted in the dry land by rain or supplemented by a small amount of irrigation rice, the lifetime irrigation amount is only 1 4 1 10 of rice, suitable for low-lying and waterlogged dry land, rain-rich mountains and rice areas with insufficient water or energy shortage.

This kind of rice is called upland rice, and it is generally grown in water-scarce areas, but it is necessary to have enough water during the heading period.

There are very few areas of cultivation now.

You can search for it online.

This is not to say that it was discovered by a single person, but that it was selected by the working people after a long period of practical activities, and finally cultivated and finalized.

Back in the past, it used to be a natural debt, but after the discovery of human beings, it was discovered that it could be used as food, and people began to practice the superiority of rice, and carried out the cultivation of rice, and now the country has carried out the research and development of rice improvement, improvement and yield increase.

Hello, it is no longer possible to study rice when it was first discovered in this way.

However, the history of rice cultivation can be traced back to Hunan, China, about 12,000-16,000 BC. In 1993, the Sino-US joint archaeological team discovered the world's earliest ancient cultivated rice in Yuchanyan, Daoxian County, about 14,000-18,000 years ago.

The first inhabitants to grow rice were the Hemudu people. Hemudu settlement is located in Hemudu Village, Yuyao, Zhejiang, about 7,000 years ago, and is a representative of clan settlements in the Yangtze River Basin.

Rice is an annual plant, generally after the first year of harvest needs to be replanted, so as to ensure that there is a good harvest every year, it can bloom, belongs to flowering plants, generally blooms around July every year, its stem is very soft, there is no abundant lignified cells, it belongs to herbaceous plants, but also angiosperms, it has seeds, generally sowing and breeding.

Is rice an annual plant.

Rice is an annual plant, it generally cannot be regarded as a perennial culture, because planting rice once a year can ensure that it has a good harvest every year, so it can not be regenerated in the second year.

Rice can live for several years.

The life span of rice is relatively short, and it generally needs to be replanted after the first year of harvest, and the life span of potted rice is also very short, basically one year's life.

What kind of plant is rice.

Rice belongs to the genus Poaceae, it can bloom, belongs to flowering plants, generally blooms around July every year, and the color of the flowers is generally pale yellow.

Rice is a herbaceous plant, its stem is relatively soft, and there is no abundant lignified cells, so it does not belong to woody plants, in addition to rice is an angiosperm, it has seeds, generally through the coarse itself and artificial to spread the seeds, its reproduction method is generally sowing.

What does rice look like.

Rice can generally grow to more than 1 meter tall, it is an upright growth tanzhen, the leaves are lanceolate, generally have a lot of branches, after maturity is downward bend growth, it prefers a warm environment.