Starchy Staples
Potatoes, yams, cassava, taro, bananas, and plantains all provide people with calories in the form of starch. Starch is often stored in underground organs (modified roots or stems). These plants can be stored underground and do not require special storage facilities.
Stolons: grows just under the surface or right above the ground, think strawberry plants
Rhizomes (ginger)
Tubers (potato)
Bulb (onion - each layer is a leaf base)
Corms: looks like a bulb, all stem (taro)
Tubers: modified fibrous root (sweet potato, yam, cassava)
Taproot: carrot
Hails from the same family as the tomato and tobacco, the Solanaceae Family.
Potatoes originated in the Andes (South America) and were domesticated ~8,000 years ago. They were taken to Spain in the 16th century where they were initially used for animal feed. Humans in Europe started eating them around the 18th century. This is most likely due to the fact that the potato plant as well as green potatoes are poisonous. They later became an Ireland staple because if growing conditions were good, you could feed an entire family on a small amount of land. Since potatoes propagate vegetatively, it is likely that a decrease in genetic diversity (heterozygosity) cause the Irish Potato Famine which occurred from 1845-1849. The Famine was caused by Phytophthora Infestans and led to the starvation of one million people and the emigration of another 1.5 million.
There are multiple varieties, white (most common), purple, and red. Potatoes propagate vegetatively (you use the potato, not the seeds).
Potatoes are the 4th best crop, they are 25% starch, and 2.5% protein and the skin provides fiber, K, Fe, and Vitamins B and C.
Hails from the same family as the Morning Glory Flower, the Convolvulaceae family.
Originated in Peru (South America) and is also eaten in Polynesia. It was taken to Europe by Columbus. It is grown pretty much everywhere - South America, China, Asia, and the US. There are two varieties grown in the US, yellow and orange which is higher in beta-carotene.
Sweet potatoes are the 9th best crop and provide lots of carbs (more sugar than regular potatoes), vitamin A, and some minerals.
Cassava also known as manioc, tapioca, yuca, yucca root, and mandioca origanted in South America. It was taken to West Africa, then in the 16th century the Portuguese also took it to Asia and it went from Mexico to Indonesia. Cassava is coated in wax for preservation in grocery stores. Like potatoes, it is propagated by stem cuttings.
Cassava is poisonous if not prepared properly. Cassava produces cyanogenic glycosides and if hydrolyzed these release HCN (hydrogen cyanide) which can cause death by cyanide poison. Cyanogenic glycosides act as herbivore deterrents. Sweet varieties of cassava have low amounts of HCN and can be prepared by boiling, steaming, or frying. Bitter varieties (more HCN) must be dried, soaked, boiled, grated, and fermented.
Cassava is the world’s 5th best crop and is the 3rd largest carb supplier. It is 80% carbs and 20% water.
35% of the world is under-nourished and many of them are children. They do not receive enough calories, protein, vitamin A, iron, or zinc. Scientists are trying to see if we can engineer cassava to provide complete nutrition. To add the iron scientist added a novel Fe transport from algae, this increases the iron accumulation in the cells of the root and is selective as it doesn’t take in other heavy metals. This transgenic line has 4x the amount of iron when compared to the wild type. To add zinc, scientists incorporated two genes the Arabidopsis ZIP1 for zinc uptake and ZAT for transport into the vacuole. The resulting transgenic line has 8x the amount of zinc. To add vitamin A, scientists inserted a gene for an enzyme in the pro-vitamin A biosynthetic pathway. The result was “golden” cassava which has 30x the beta-carotene. Vitamin E was supplemented using the bacterial crtB gene to increase the synthesis of tocotrienols (vitamin E family). To fix the protein deficiency, scientists are attempting to overexpress a fusion of corn and bean gene that overexpresses a high-quality storage protein. We also need to make cassava less toxic, the goal is to reduce the cyanogenic glucoside without reducing herbivore resistance (field trials are ongoing). This is currently the most ambitious plant bioengineering project ever attempted.
True yams are a dietary staple in West Africa, Southeast Asia, the Pacific Islands, and the Caribbean. In most places, however, yams are being replaced by cassava because yams require more labor. Yams have been used as a source of steroids for laboratory conversion into oral contraceptives.
Yams are the world’s 12th-best crop with a high starch content and only ~2% protein.
Taro is a corm (a type of underground stem) and is cultivated extensively in Hawaii and other wet tropical regions.
Bananas and plantains are collectively the world’s 10th-best crop. They are starchy fruits. Plantains are eaten as a vegetable while bananas are eaten as fruit. Cultivation is labor intensive and involves the spraying of lots of fungicides. Due to the low price of bananas, many wonder if there is an exploitation of labor.
Potatoes, yams, cassava, taro, bananas, and plantains all provide people with calories in the form of starch. Starch is often stored in underground organs (modified roots or stems). These plants can be stored underground and do not require special storage facilities.
Stolons: grows just under the surface or right above the ground, think strawberry plants
Rhizomes (ginger)
Tubers (potato)
Bulb (onion - each layer is a leaf base)
Corms: looks like a bulb, all stem (taro)
Tubers: modified fibrous root (sweet potato, yam, cassava)
Taproot: carrot
Hails from the same family as the tomato and tobacco, the Solanaceae Family.
Potatoes originated in the Andes (South America) and were domesticated ~8,000 years ago. They were taken to Spain in the 16th century where they were initially used for animal feed. Humans in Europe started eating them around the 18th century. This is most likely due to the fact that the potato plant as well as green potatoes are poisonous. They later became an Ireland staple because if growing conditions were good, you could feed an entire family on a small amount of land. Since potatoes propagate vegetatively, it is likely that a decrease in genetic diversity (heterozygosity) cause the Irish Potato Famine which occurred from 1845-1849. The Famine was caused by Phytophthora Infestans and led to the starvation of one million people and the emigration of another 1.5 million.
There are multiple varieties, white (most common), purple, and red. Potatoes propagate vegetatively (you use the potato, not the seeds).
Potatoes are the 4th best crop, they are 25% starch, and 2.5% protein and the skin provides fiber, K, Fe, and Vitamins B and C.
Hails from the same family as the Morning Glory Flower, the Convolvulaceae family.
Originated in Peru (South America) and is also eaten in Polynesia. It was taken to Europe by Columbus. It is grown pretty much everywhere - South America, China, Asia, and the US. There are two varieties grown in the US, yellow and orange which is higher in beta-carotene.
Sweet potatoes are the 9th best crop and provide lots of carbs (more sugar than regular potatoes), vitamin A, and some minerals.
Cassava also known as manioc, tapioca, yuca, yucca root, and mandioca origanted in South America. It was taken to West Africa, then in the 16th century the Portuguese also took it to Asia and it went from Mexico to Indonesia. Cassava is coated in wax for preservation in grocery stores. Like potatoes, it is propagated by stem cuttings.
Cassava is poisonous if not prepared properly. Cassava produces cyanogenic glycosides and if hydrolyzed these release HCN (hydrogen cyanide) which can cause death by cyanide poison. Cyanogenic glycosides act as herbivore deterrents. Sweet varieties of cassava have low amounts of HCN and can be prepared by boiling, steaming, or frying. Bitter varieties (more HCN) must be dried, soaked, boiled, grated, and fermented.
Cassava is the world’s 5th best crop and is the 3rd largest carb supplier. It is 80% carbs and 20% water.
35% of the world is under-nourished and many of them are children. They do not receive enough calories, protein, vitamin A, iron, or zinc. Scientists are trying to see if we can engineer cassava to provide complete nutrition. To add the iron scientist added a novel Fe transport from algae, this increases the iron accumulation in the cells of the root and is selective as it doesn’t take in other heavy metals. This transgenic line has 4x the amount of iron when compared to the wild type. To add zinc, scientists incorporated two genes the Arabidopsis ZIP1 for zinc uptake and ZAT for transport into the vacuole. The resulting transgenic line has 8x the amount of zinc. To add vitamin A, scientists inserted a gene for an enzyme in the pro-vitamin A biosynthetic pathway. The result was “golden” cassava which has 30x the beta-carotene. Vitamin E was supplemented using the bacterial crtB gene to increase the synthesis of tocotrienols (vitamin E family). To fix the protein deficiency, scientists are attempting to overexpress a fusion of corn and bean gene that overexpresses a high-quality storage protein. We also need to make cassava less toxic, the goal is to reduce the cyanogenic glucoside without reducing herbivore resistance (field trials are ongoing). This is currently the most ambitious plant bioengineering project ever attempted.
True yams are a dietary staple in West Africa, Southeast Asia, the Pacific Islands, and the Caribbean. In most places, however, yams are being replaced by cassava because yams require more labor. Yams have been used as a source of steroids for laboratory conversion into oral contraceptives.
Yams are the world’s 12th-best crop with a high starch content and only ~2% protein.
Taro is a corm (a type of underground stem) and is cultivated extensively in Hawaii and other wet tropical regions.
Bananas and plantains are collectively the world’s 10th-best crop. They are starchy fruits. Plantains are eaten as a vegetable while bananas are eaten as fruit. Cultivation is labor intensive and involves the spraying of lots of fungicides. Due to the low price of bananas, many wonder if there is an exploitation of labor.
