XVI International Botanical Congess

Two major challenges are facing seed regulatory and testing officials. One involves the development of new genetically engineered varieties having resistance to various herbicides, insects, or producing modified products. Seed regulatory officials feel obligated to test samples of these varieties to verify product claims. No official testing procedures have been approved for these varietal attributes. Some laboratories have developed their own procedures for testing seed samples for herbicide resistance. These involve germinating seeds in media soaked with herbicide, soaking seeds in herbicide prior to planting, or spraying seedlings with an herbicide solution. The developing seedlings are evaluated for herbicide injury. A second challenge involves using seeds of native species in revegetation and roadside plantings. Seeds of most of these species have awns that promote seed dispersal in nature, but cause seeds to clump together when sampled and during testing for pure seed content. It is difficult to determine germination percentages for samples of these species because they contain high percentages of dormant seed. In addition, seeds collected from populations of a species located in different environmental areas can have different requirements for germination.