ARS | Publication request: Germination Under Stress: A Marker For Inherent Vigor Or An Isolated Event?

Submitted to: Plant and Animal Genome Conference
Publication Type: Abstract Only
Publication Acceptance Date: January 10, 2010
Publication Date: January 10, 2010
Citation: Naegele, R., McGrath, J.M. 2010. Germination Under Stress: A Marker For Inherent Vigor Or An Isolated Event? [abstract]. Plant and Animal Genome Conference. Paper No. W595.

Technical Abstract: Seedling vigor and its translation to late-season vigor are, at best, murky for most beet breeders. The initial conditions a germinating seed encounters, and its ability to overcome them, affects stored energy reserves to withstand future adverse environments and the ability of the seedling to survive and flourish. However, the use of seedling molecular markers to assess vigor is not currently possible. Germination is too poorly understood and the connection between seedling and late-season vigor is over laden with environmental factors. Germination is a stressful time to a plant, but stress levels are dependent upon moisture, temperature and biotic pathogens, which are also factors for adult beets. To understand differences in seedling vigor under stress and identify key pieces of environmental response pathways, a germination scaffold under “typical” stress was created. Three varieties were tested for differences in vigor when germinated under stressed (H2O) and non-stressed (H2O2) conditions in the lab, physically using imbibition data and genetically using gene expression data from 0 to 96 hours. Results demonstrated speed to radical emergence and number germinated for each variety were different, and imbibition rates showed no significant differences. Rate of imbibition was highest between 0 and 24 hours and gene expression was measured during this time. Over 50 genes, measuring development and stress response functions, were analyzed and compared between varieties and treatments. Genes with patterns of expression correlating to increased vigor were compared to their expression patterns in the same three varieties 3 weeks after germination under similar stress conditions.