Chlorogenic acid content in sweetpotato germplasm: possible role in disease and pest resistance.

摘要

Fourteen sweet potato clones, representing wide genetic diversity, were grown in the field in Charleston, South Carolina, USA under low stress conditions. Chlorogenic acid contents were determined in the periderm and cortex tissues of these clones. On dry weight basis, chlorogenic acid content in the periderm tissues ranged from 33 to 214 micro g g-1 dry tissue and that in the cortex ranged from 1416 to 4213 micro g g-1 dry tissue (181 to 1384 micro g g-1 on fresh weight basis). In vitro bioassays were done to assess the bioactivity of chlorogenic acid on seed germination of proso millet (Panicum miliaceum), growth of four sweet potato pathogenic fungi (Fusarium oxysporum f.sp. batatas, F. solani, Lasiodiplodia theobromae and Rhizopus stolonifer), and growth and survival of diamondback moth larvae (Plutella xylostella). The highest levels of chlorogenic acid occurring in sweet potato cortex tissue exceeded the lowest concentrations that inhibited the growth and survival of diamondback moth larvae and the growth of three of four sweet potato pathogenic fungi tested..