The Ohio State University Seed Biology Program addresses seed quality issues of important agricultural crops. Because of the high value and need for optimum seed performance in floricultural crops, particularly bedding plants, the study of ornamental seed biology is of particular interest. Dr. Miller McDonald is investigating the following methods to improve ornamental seed performance:

Saturated Salt Accelerated Aging Test. The standard accelerated aging vigor test has not been useful for small-seeded ornamental crops because they deteriorate too rapidly. This research substituted saturated salt solutions for water which reduced the relative humidity of the test from 100% to 76% thereby slowing the aging process and simultaneously decreasing fungal contamination. Such a modification allows the vigor testing of small-seeded ornamental crops and was shown to be useful for impatiens and pansy seeds as reported in Seed Science and Technology 25:123-131 and GrowerTalks, Winter 1996.

Genetic Purity Testing. All seeds must be genetically uniform for optimum crop performance and appearance. Presently, most seed companies use morphological tests to evaluate important traits such as flower color, leaf shape, etc. However, advances in biotechnology now permit routine examination of genetic information at relatively low cost. One of these involves a modification of the Polymerase Chain Reaction that amplifies small quantities of DNA in seeds to amounts sufficient to be resolved on electrophoretic gels. McDonald showed that differing electrophoretic banding patterns characteristic of differing petunia and cyclamen varieties were possible as reported in HortScience 32:246-247 and GrowerTalks, Winter 1996.

Standardizing Seed Germination. Seed germination results seldom reflect greenhouse seed performance. Much of this is due to companies using differing germination protocols to assist bedding plant producers in predicting performance. However, since each company uses a different germination procedure, results vary and bedding plant producers desire more standardized testing. A "referee" is being conducted in conjunction with major floricultural seed companies to determine what are the best germination conditions for the most important floricultural crops. These will be identified as the standard germination procedures for each company. An ultimate goal of this project is the development of a "Flower Seed Testing Handbook."

Seed Enhancements. Bedding plant producers are willing to make additional investments for enhanced seeds. Many of the variables in producing and improving enhanced seed performance, however, still remain poorly understood. Studies are being conducted to define the physiology of seed response to enhancement protocols, particularly for pregerminated seeds.