Sweet potato is native to South America and the big and small Antilles, and is widely planted in tropical and subtropical areas all over the world, and also in most parts of China.
Sweet potato is a kind of food crop with high yield and strong adaptability, which is closely related to industrial and agricultural production and people's life. Truffle is not only the main grain, but also an important raw material for food processing, starch and alcohol manufacturing industries. Roots, stems and leaves are excellent feeds.
morphological character
Panicum miliaceum, the underground part has round, oval or spindle-shaped roots. The shape, skin color and flesh color of tuberous roots vary with varieties or soils. Stems procumbent or ascending, occasionally twining, multi-branched, cylindrical or angular, green or purple, sparsely pilose or hairless, and stems are prone to adventitious roots.
sweet potato
The shape and color of leaves are often different for different varieties, and sometimes there are different leaf shapes on the same plant. Generally, it is a broad oval, 4- 13cm long and 3- 13cm wide, with 3-5(-7) lobes, a broad oval, a triangular oval or a linear lanceolate shape, and the leaves are heart-shaped or nearly truncated at the base and tapered at the top. Petioles vary in length, 2.5-20 cm long, sparse or glabrous.
Cymes axillary, 1-3-7 flowers cymose, peduncle 2- 10.5 cm long, slightly stout, glabrous or sometimes puberulent; Bracts are small, lanceolate, 2-4 mm long, with awns or acute tips, caducous; Pedicel length 2- 10 mm; Sepals are oblong or oval, with different lengths. The outer sepals are 7- 10 mm long, the inner sepals are 8- 1 1 mm long, and the top suddenly becomes awn-pointed, with no hair or sparse cilia. Corolla pink, white, lavender or purple, bell-shaped or funnel-shaped, 3-4 cm long, glabrous outside; Stamens and styles are embedded, and filaments are hairy at the base; Ovary 2-4-loculed, hairy or sometimes glabrous.
Flowering habits vary with varieties and growth conditions. Some varieties are easy to bloom, others will bloom when the climate is dry, which is common in areas with high temperature and short sunshine, and rarely blooms in areas with low temperature. The capsule is ovoid or oblate, with a false diaphragm and divided into 4 cells. Seeds 1-4, usually 2, glabrous. Because sweet potatoes are cross-pollinated, self-pollination often does not bear fruit, so sometimes they only bloom and do not bear fruit.
Main value
nutrition
Sweet potato is a natural nourishing food with comprehensive nutrition, which is rich in protein, fat, polysaccharide, phosphorus, calcium, potassium, carotene, vitamin A, vitamin C, vitamin E, vitamin B 1, vitamin B2 and 8 kinds of amino acids. According to the analysis of scientists, its protein content is more than 7 times that of rice; The content of carotene is 3.5 times that of carrot; The content of vitamin A is 100 times that of potato. The contents of sugar, calcium, vitamin B 1 and vitamin B2 are higher than those of rice and flour. The edible part of each100g fresh potato block contains 29.5g of carbohydrate, 0.2g of fat, 20mg of phosphorus, 0.8mg of calcium/kloc-0, and 0.4g of iron. These substances play an important role in promoting the activity of human brain cells and secreting hormones, enhancing human disease resistance, improving immune function, and delaying mental decline and physical aging. The Japanese Ministry of Health has listed it as an important food for dietotherapy. [ 1 1]
Diet food: The fat content of sweet potato is extremely low (0.2%), which is incomparable to other foods. But the content of unsaturated fatty acids is very rich. Take it as a staple food and eat it once a day. Its rich cellulose makes people feel "full of wine and food" and relaxed. At the same time, it can not only prevent the absorption of fat and cholesterol in the intestine, but also decompose cholesterol in the body, promote lipid metabolism, effectively prevent the body from overnutrition and resist obesity, so as to achieve the purpose of losing weight.