Presence of free arginine associated with susceptibility to lethal yellowing of palms

Thin-layer chromatographic evaluations of the distribution patterns of 28 free amino acids and amines in the foliage of 18 species and cultivars of Palmae grown in Florida revealed that arginine was readily detected in susceptible palm types, but was absent or present at minimal detectable levels in resistant or immune palms. No apparent relationship could be discerned for any other amino acid as far as varietal resistance to lethal yellowing disease was concerned. Additional studies to verify this potential relationship by high-performance liquid chromatography are in progress. This information can be of value in breeding programs selecting for palm cultivars resistant to this disease. These data also suggest that the lethal yellowing mycoplasma-like organism may hydrolyze arginine.