Unformatted text preview: ber, accompanied by an increase in seed size. b. Loss of fertility, particularly true for crops in which economic portion is not the seed. Many cultivated sweet potatoes no longer F ower. Many cultivated crops are seedless, such as banana, orange. Thus, crops are often dependent on humans for sur-vival. 3. Loss of survival characters Shattering ability in grains Potatoes- tubers borne close to plant in domestic types, spread in wild types Thin vs. thick shells in nuts Fig. 3-6. Wild and domesticated forms of einkorn wheat. Wild forms needs to disperse seeds effectively and has thus evolved easily shattered ears with brittle rachises and thin, arrow-shaped spikelets designed to penetrate surface litter and em-bed themselves in cracks in the ground. In domesticated form, plumper spikelets have lost some of the key structures necessary for self-implantation, seed dispersal, and suc-cess in the soil. Source: Smith 1994, p. 73....
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- Summer '10
- History, wild plants, seed num- rachises, gross genetic changes