National Crops Resources Research Institute (NaCRRI), P.O. Box 7084, Kampala, Uganda.
J Agric Food Chem. 2013 Aug 28;61(34):8141-7. doi: 10.1021/jf4024992. Epub 2013 Aug 16.
Seven resistant varieties of sweetpotato were compared with three susceptible varieties in field trials and laboratory bioassays and showed that resistance was an active process rather than an escape mechanism, as field resistant varieties also had reduced root damage and oviposition compared with susceptible varieties in the laboratory. Liquid chromatography-mass spectrometry (LC-MS) of root surface and epidermal extracts showed significant variation in the concentration of hexadecyl, heptadecyl, octadecyl, and quinic acid esters of caffeic and coumaric acid, with higher concentrations correlated with resistance. All compounds were synthesized to enable their positive identification. Octadecyl coumarate and octadecyl caffeate applied to the surface of susceptible varieties in laboratory bioassays reduced feeding and oviposition, as observed on roots of resistant varieties, and therefore are implicated in weevil resistance. Segregating populations from breeding programs can use these compounds to identify trait loci for resistance and enable the development of resistant varieties.
七种抗甘薯品种与三种感病品种进行了田间试验和实验室生物测定比较，结果表明，抗性是一个主动的过程，而不是逃避机制，因为田间抗性品种与感病品种相比，在实验室中也减少了根损伤和产卵。根表面和表皮提取物的液相色谱-质谱（LC-MS）分析显示，咖啡酸和香豆酸的十六烷基、十七烷基、十八烷基和奎尼酸酯的浓度有显著差异，与抗性呈正相关。所有化合物均进行了合成，以能够对其进行阳性鉴定。十八烷香豆酸酯和十八烷咖啡酸酯施用于实验室生物测定中感病品种的表面，减少了取食和产卵，这与在抗性品种的根上观察到的情况一样，因此与象鼻虫的抗性有关。从育种计划中分离出来的群体可以使用这些化合物来鉴定抗性的性状基因座，并能够开发出抗性品种。
