Dealing with Seed Dormancy.

Seed dormancy is a form of developmental arrest that protects plant species against extinction and synchronizes plant establishment to local environmental cycles of temperature and rainfall, as well as light availability and soil nutrition. It is common especially in wild and native species. Forms of dormancy are diverse and interactive, ranging from impermeable seed coats (hardseededness) to sophisticated physiological dormancy blocks that are sensitive to various forms of nitrogen, stratification (extended cold or warm temperature periods), lack of water (dry-afterripening), smoke and light.  Most dormancy syndromes can be rationalized as environmental sensors. Here, the classes of dormancy will be reviewed along with information resources and a flow-sheet strategy to diagnose and overcome dormancy for evaluation of seed quality. The rationale for breaking dormancy (or not) for conservation or restoration will be considered.