Editor's note: From the deep sea to the mountains, from deserts to rainforests, plant imprints are found everywhere on earth. A world of changing years, climate change, geological movement, habitat change, plants that have endured and remain diverse in evolution. Voice of the Chinese Academy of Sciences and the Wuhan Botanical Garden of the Chinese Academy of Sciences jointly opened "Flowers and Flowers of All Things", where we pay attention to the survival, competition, reproduction and death of plants, display the strange and colorful nature of the natural world, interpret the thousands of meteorological phenomena of life, explore the magical secret of life, and pay tribute to this silent and vigorous world.
"In the field next to the woods grows a large field of peanuts, green leaves, and small yellow flowers, which are eye-catching and endearing. The little squirrel asks the little mole what kind of flower it is, and the little mole says that it is the flower of peanuts, and in the autumn it will pick up delicious fruits. The little squirrel was happy, thinking in his heart, when the peanuts were fruitful, he would go and pick some and come back, and keep them for the winter to eat. Since then, the little squirrel has gone to the ground every day to look at peanuts, but until all the yellow flowers have fallen, they have not seen a single peanut. It opened its eyes and said to itself, 'Strange, who took the peanuts away?' ’”
This is the text of "Little Squirrel Finds Peanuts" in the Chinese textbook of the first grade of primary school. In the autumn school season, when the peanuts are ripe, follow the text to find the missing peanuts and see who picked them.
Peanut field (Image source: China Plant Image Library)
What do flowers look like?
Peanut is the common name of the fallen peanut (Arachis hypogaea L.), also known as the long fruit, ground bean, tomato bean, is an annual herb of the legume genus of the genus Peanut, suitable for growing in a warm climate, long growing season, moderate rainfall in sandy land areas, in the mainland, with Shandong as the best production area. Like members of the legume family, peanuts have rich roots with nodules, and colonized rhizobia benefit from them and coexist. Peanuts provide mineral nutrients and energy for rhizobia growth; Rhizobia provide nitrogen nutrients for peanut growth by fixing free nitrogen in the atmosphere. When flowering, the golden yellow flowers resemble butterflies spreading their wings and are hidden in a field of turquoise leaves. The fruit is a pod, which is swollen and thick with delicious seeds.
Peanut seed germination process (Source: China Plant Image Library)
Seedlings of peanuts
Peanuts flowers
The fruit of a peanut
Where did the fruit of the peanut go?
Plants on land, usually flowering on the ground and bearing fruit on the ground, while falling peanuts are rare plants that flower on the ground and bear fruit underground. How do peanuts achieve the results of entering the ground? This is because the fallen peanut has a special equipment - "fruit needle". After fertilization of the original flower of the peanut, the tissue at the base of the ovary will quickly differentiate, growing downward into a long sub-chamber handle, and the small, bulging sub-room is placed at the top of the sub-room handle, and the overall appearance is especially like a needle for sewing clothes, so the sub-room handle and the ovary are collectively called "fruit needles". The needle continues to elongate downward during the growth process until it touches the ground, and then it protrudes into the soil, allowing the ovary to expand and develop in a dark environment.
Peanut needle (image from the Internet)
Why did peanuts get into the ground?
The mechanism of falling peanuts into the ground is more complicated, but scientists through practical observation and experimental exploration generally believe that the dark environment is a necessary condition for the results of falling peanuts. Scientists in the process of fruit needle growth, so that it grows in the air, does not stick into the soil, observation found that it can only grow can not bear fruit; However, by experimenting, it is extended into a blackout bottle, and the ovary can expand and develop fruitfully. It can be seen that when cultivating fallen peanuts, it is necessary to choose a loose soil that is conducive to the penetration of fruit needles, create dark fruit conditions for them, and improve the fruit setting rate.
Peanuts in the soil (Source: China Plant Image Library)
Peanut fruit (Image source: China Plant Image Library)
Where do peanuts come from?
Regarding the origin of the fallen peanut, according to the "Flora of China" record, according to the literature, there are three theories of origin brazil, origin of China, origin of Egypt, etc., but the synthesis of various texts believes that Brazil originating in South America is more reasonable. Scientists have found wild plants in many parts of South America, ranging from the Atlantic coast in the west to the Andes Mountains in the east, to the Amazon estuary in the north, to Uruguay in the south, covering brazil, Paraguay, Argentina, Bolivia and Uruguay, of which the largest number of wild species is in the central region of western Brazil.
When peanuts were introduced to China has also been controversial. According to the current historical data, the mainland records of falling peanuts began in the Ming Dynasty, and the more reliable record is the Jiangsu "Chronicle of Changshu County" in 1503 (the sixteenth year of Ming Hongzhi), which contains: "Falling peanuts, planted in March, the introduction of vines is not very long." The common cloud flower falls to the ground, and the child is born in the soil, hence the name. Cooked and edible after frosting, it tastes delicious. "Nowadays, it is generally believed that the fallen peanut was introduced to China in the Ming Dynasty, initially planted in Fujian, Guangdong and other places, and later gradually introduced to other regions. The "Yu Hengzhi Zhiguo of the Dianhai Sea" records that the peanuts in Guangdong are "planted by the Cantonese people from the sea countries." "Peanuts have a high oil content and are a good raw material for oil extraction. After being introduced to the mainland, it soon became an important oil crop, and by the mid-19th century, peanut cultivation was almost all over the country.
What are the responsibilities of peanuts?
Rich in fat and protein, it is a high-quality source of calories and protein, and is one of the oilseeds and cash crops widely cultivated in the world, integrating edible and oil, with a wide range of uses, and has an important position in the national economic and social development of the mainland. The "Chronicle of Huimin County" details the functional use of falling peanuts: "Spring sowing, vine compound leaves, yellow flowers, needles under the flowers, inserted into the soil to bear fruit, after autumn to cut their vines, out of their fruits, off their shells into rice, easy to sell, and can be squeezed oil for cooking food, oil residue can be used as feed and fertilizer, but also for human consumption." ”
In addition to nut pressing and edible, the stems and leaves, peanut shells and oil meal of fallen peanuts also have high use value. Stems and leaves can be used to make a knife feed; Oil meal can be filled with refined feed and can also be fertilized; Peanut shells make up about one-third the weight of the scale and can be used as fuel, compost or roughage for pigs. Under the application of modern technology, the use of biotechnology and chemical technology at home and abroad has comprehensively developed and utilized peanut shell resources, and as a low-carbon economy, it has been applied to the extraction of functional substances, agricultural feed, cultivation substrates, adhesives, adsorbents and other fields, and has made good progress.
Plants support human food, clothing, shelter and transportation, and are closely related to people's lives. When completing the journey of life, the seeds of falling peanuts are calm and self-assured, and they work hard to grow, which brings great convenience to human beings. In the spring, in the gardening and planting class of Wuhan Botanical Garden, the seeds of falling peanuts were planted with the children. In the cycle of the seasons, the fallen flowers have grown green leaves, bloomed yellow flowers, and now the heavy fruits are buried in the soil, waiting for us to pick and feel the joy of the harvest.
Bibliography:
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4. LIU Ying. Research on crop oilseeds in ancient China[D].Northwest A&F University,2009.]
5. Flora of China http://www.iplant.cn
Source: Wuhan Botanical Garden, Chinese Academy of Sciences