Location: Plant Germplasm Introduction and Testing
Title: Natural outcrossing rate of faba bean under Pullman field conditions and its implication to germplasm management and enhancement Authors
Submitted to: North American Pulse Improvement Association
Publication Type: Abstract Only
Publication Acceptance Date: September 15, 2011
Publication Date: November 3, 2011
Citation: Hu, J., Landry, E.J., Mweng, J.E., Coyne, C.J. 2011. Natural outcrossing rate of faba bean under Pullman field conditions and its implication to germplasm management and enhancement. North American Pulse Improvement Association. Biennial Meeting, Nov 3-4, San Juan, Puerto Rico, USA. Technical Abstract: The US faba bean (Vicia faba L.) germplasm collection is managed by the cool season food legume curator of the Western Regional Plant Introduction Station (WRPIS) in Pullman, Washington, USA. Knowledge of the natural outcrossing rate of this crop under Pullman field conditions will enable us to refine strategies for both germplasm management and enhancement. We used the white flower phenotype governed by a recessive gene in the investigation of the natural outcrossing rate of faba bean. Seeds from white flowered plants grown in Pullman in 2010 were harvested and planted plant-to-row in spring 2011. During flowering, the number of plants with white or regular colored flowers was recorded for each row. The percentage of plants with regular colored flowers was used as an estimate of natural outcrossing rate, which averaged 30.8% and ranged from 0 to 82.6 % among 50 single-plant-derived rows. This observed outcrossing rate is within the range of previous reports for faba bean grown in various locations. The high outcrossing rate is likely the result of abundant bumble bees and honey bees which visited the faba bean flowers frequently during bloom. Therefore, for germplasm management it is necessary to regenerate faba bean accessions using insect-proof cages to maintain the genetic integrity of individual accessions. For germplasm enhancement using phenotypic selection, it is also crucial to physically isolate the selected plants with insect-proof bags to prevent unwanted cross-pollinations and produce self-pollinated seeds for subsequent generations.