Seed Biotechnology Center
Seed Biotechnology Center
Seed Biotechnology Center
University of California
Seed Biotechnology Center

Seed physiology and technology

Seed respiratory patterns during germination

As soon as they take up water, seeds begin to respire in order to generate the energy required to power germination. The Bradford lab has been testing the capabilities of an instrument, the Astec Q2, that can measure the respiratory patterns of individual seeds during germination. Pedro Bello has developed new ways to analyze this data that make the results more readily understandable and amenable to mathematical modeling analyses that are commonly applied to seed germination data. This would enable Q2 data to substitute for labor-intensive determinations of germination time courses to assay for seed vigor, aging and other applications. This research is supported by a consortium of seed and seed technology companies (Bejo Zaden, Callas International, Germain’s Technology Group, Hoopman Equipment, INCOTEC, Monsanto, Rhino Research, Rijk Zwaan, and SESvanderHave).

Metabolomics of seed germination

With support from the American Seed Research Foundation, the Bradford lab is working with Oliver Fiehn of the West Coast Metabolomics Center at UC Davis to analyze changes in the small metabolites that accompany germination. PhD student Dominique Ardura has sampled lettuce seeds at various times after imbibition and quantified several hundred metabolites. In addition, seeds were selected based on their respiratory patterns as revealed by the Q2 instrument (see above). This will enable direct comparisons between the respiration (oxygen consumption) rates of seeds and the respiratory pathways that are utilized in the early stages of seed activation following imbibition.

Stratification requirement for seed dormancy alleviation of a wetland weed

Many weed seeds require a period of moist chilling in order to alleviate dormancy. Among these is Echinochloa orizicola, a common weed in rice fields in California. Kent Bradford worked with PhD student Louis Boddy and Plant Science Department colleague Albert Fischer to analyze the responses of seeds of E. orizicola to chilling. The hydrothermal time model was applied to quantify changes in germination rates and dormancy in response to chilling treatments. The results indicated that manipulation of field conditions to promote dormancy alleviation of E. oryzicola seeds might contribute to seed bank depletion by promoting germination and enabling post-emergence seedling weed control.

Seed Systems project develops novel seed drying and storage strategies for humid regions

Kent Bradford and collaborators in Thailand, Bangladesh, Nepal, India and Kenya are conducting a 3-year project to improve and disseminate a novel method for seed drying using desiccant “drying beads.” The project, supported by $1 million from the US Agency for International Development (USAID) and the Horticulture Innovation Laboratory based at UC Davis, is demonstrating how the drying beads can be used to dry seeds to safe storage moisture contents even in rainy and high humidity climates. Drying and storage in hermetic containers also protect the seeds from damage due to molds, insects and rodents. The drying bead technology is scalable from individual farmers and local seed cooperatives to large industrial seed drying and storage facilities. The project has also developed simple methods for determining seed moisture contents and is promoting a “dry chain” concept for drying, packaging, transport and storage of seeds and dried commodities. For more information, see

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