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Dandelions dispensed with their need for males during the Ice Ages, when they evolved into self-cloning maestros of exceptional fertility and vigor. Gardeners worldwide now curse the pesky weed for its asexual reproductive prowess. But plant geneticists are in awe. Asexual seed production (apomixis) rarely occurs in nature. If the process could be duplicated, it could make agriculture, horticulture and forestry more productive and efficient. Utah State plant geneticist John Carman recently became the first to induce the process in the lab. Carman has been studying apomixis since his arrival on campus 22 years ago. Like other plant geneticists, he recognized the value of induced apomixis to food, flower and tree producers. Hybrid seeds, which have been a boon to farmers and an economic windfall for seed companies, have been around since the early 1930s, but they are good for only one generation. And the labor intensity of producing them makes them too expensive for widespread use in developing countries. Apomixis immortalizes a hybrid. The genes responsible for superior yields are passed from one generation to the next. If apomictic seeds were available for wheat, rice and other crops that are not grown as hybrids, yields would rise by as much as 50 percent. The increased yield in one crop alone, rice, could feed one billion additional people, says Carman. Duplicating what nature has accomplished in a small percentage of plants was no small feat. Carman and his graduate students scoured the Arctic and the Rocky Mountains from Canada to Mexico for the sexual ancestors of some of today's natural apomicts. Most of these ancestors evolved during the Ice Ages, when sexual plants from harsh, cold climates migrated to lower, warmer latitudes and cross-bred with close relatives to produce new hybrids from which the asexual reproducers developed. more
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