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ARS Home » Northeast Area » Geneva, New York » Plant Genetic Resources Unit (PGRU) » Research » Research Project #436542

Research Project: Regeneration of Short-Day Onions

Location: Plant Genetic Resources Unit (PGRU)

Project Number: 8060-21000-031-003-S
Project Type: Non-Assistance Cooperative Agreement

Start Date: Jun 30, 2019
End Date: Jun 29, 2024

The objective of this cooperative agreement is to regenerate accessions of the short-day Allium cepa collection maintained by the Plant Genetic Resources Unit, (PGRU) in Geneva, NY. These accessions will be regenerated because of either reduction in viability below acceptable standards and/or low seed supply due to seed distributions. These accessions must be regenerated so that the short-day onion germplasm collection may be distributed. Short-day onions cannot be regenerated in Geneva, NY because of short day length requirements to initiate flowering and also to initiate bulbing. Short day onions require a day length of shorter than 13 hours to initiate bulbing and flowering, whereas in Geneva during the growing season the day length is longer than this due to latitude. Therefore, there is a need for regular routine regeneration of these accessions on a recurring basis.

The PGRU vegetable curator will identify the short-day onions that require regeneration. The accessions that are in most need of regeneration each year will be prepared and sent to New Mexico State University for regeneration. At New Mexico State University, the accessions will be seeded in seedling flats. Once plants have reached a large enough size, they will be transplanted to a field for bulb production. Plants will be grown over the winter. Once the plants have matured the following summer, bulbs will be collected from each accession and will be stored at ambient conditions for 3-4 months. Once bulbs begin to break dormancy, they will be set in a seed production field. The following spring, a 10’ x 10’ cage will be placed over the bulbs from each accession. Once the bulbs have flowered, blowflies will be introduced into each cage for flower pollination. After one month, the mature seed for each accession will be harvested, dried, and cleaned. The seed produced from the regeneration will be transferred to PGRU. At PGRU, the seed will be dried and germination tests conducted. Then seed stock inventory status will be updated in the GRIN-Global database.