Define stratification and scarification and give an example of a seed type that requires each for germination.

Define stratification and scarification and give an example of a seed type that requires each for germination.

• A. Stratification is a cold treatment to break dormancy; scarification is mechanical or chemical abrasion of the seed coat; temperate tree seeds require stratification; nasturtium seeds require scarification
• B. Stratification is heat treatment; scarification is soaking seeds; maize requires stratification
• C. Stratification is exposure to light to germinate; scarification is darkness; beans require stratification
• D. Stratification is chemical soaking; scarification is drying; pine requires scarification

Answer: (A)

Dormancy-breaking techniques for seeds: stratification and scarification. Stratification is a cold, moist treatment that mimics winter and helps seeds with physiological dormancy break dormancy so they germinate when conditions improve in spring. Scarification is the mechanical or chemical abrasion of the seed coat to weaken or breach a hard coat, allowing water and gases to reach the embryo and trigger germination. A common example is seeds of temperate trees that require a period of cold-moist stratification to germinate. Nasturtium seeds, with their relatively tough coats, often benefit from scarification to improve germination.