Indole-3-acetic Acid (IAA) Content and Axillary Bud Development in Relation to Russet Spotting in Harvested Iceberg Lettuce

in Journal of the American Society for Horticultural Science
View More View Less
  • 1 Department of Vegetable Crops, Mann Laboratory, University of California, Davis, CA 95616-8631
  • | 2 Department of Pomology, University of California, Davis, CA 95616-8683
  • | 3 Eagle Research, P.O. Box 1981, Salinas CA 93902
  • | 4 Department of Vegetable Crops, Mann Laboratory, University of California, Davis, CA 95616-8631

This study was undertaken to determine if endogenous IAA content and axillary bud development correlate with phenylalanine ammonia-lyase (PAL) induction and russet spotting (RS) susceptibility among RS susceptible and resistant cultivars of Iceberg lettuce (Lactuca sativa L.). Final levels of ethylene-induced PAL activity and RS development were highly correlated among cultivars, field conditions, and harvest dates. Harvested Iceberg lettuce midribs contained relatively low amounts of free IAA (maximum of 5.2 ng·g-1 fresh weight). There was poor correlation between free IAA content in lettuce leaf midribs and final RS development among all cultivars, growing conditions, and harvest dates. Axillary bud development, as measured by the number of visible buds per head, bud weight, or bud length, were not significantly correlated with final RS development or midrib IAA content. Cultivars with higher initial free IAA content lost much of their IAA after 8 days storage at 5C in air ± ethylene.

All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 86 23 4
PDF Downloads 91 44 1