Changes in gluconasturtiin concentration in Chinese cabbage with increasing cabbage looper density.

摘要

Changes in the level of gluconasturtiin (2-phenylethyl glucosinolate), an aromatic glucosinolate, were used to evaluate the response of cv. Green Rocket Chinese cabbage to feeding of 3 and 5 cabbage looper larvae per plant. Plants were harvested 0, 10 and 17 days after infestation. The change in gluconasturtiin concn. resulting from decreased light capture from diminished leaf area was also studied. All samples were assayed for gluconasturtiin concn. using HPLC. Gluconasturtiin concn. of plants subjected to 5 larvae per plant showed a 59% increase 10 days after infestation compared with noninfested plants. The difference in gluconasturtiin concn. between 3 and 5 larvae per plant was nonsignificant. 17 days after initial infestation and 7 days after larvae were removed (final harvest), gluconasturtiin concn. did not decrease compared with the previous harvest. Reduced light or leaf area removal did not affect gluconasturtiin concn. markedly.