Kentucky State University
Screening Wild Tomato Accessions for Sugar-Ester Contents
Institution
Kentucky State University
Faculty Advisor/ Mentor
George F. Antonious
Abstract
Both native and greenhouse populations of Lycopersicon pennellii Corr. (a wild relative of commercial tomato, L. esculentum) have sticky exudates known as sugaresters (glycolipids) covering their leaves and stems. L. pennellii resistance to important vegetable pests has been attributed primarily to type-IV glandular trichome secretions. This study was initiated to extract and quantify sugar-esters in four wild tomato accessions (PI-503516, PI-246502=LA 716, PI-365972=LA 1277, and PI414773) of L. pennellii which have long been known to entrap insect pests in their sticky exudates. Extracts of glandular trichomes containing sugar-esters were prepared in chloroform and reconstituted in ethanol. A simplified micro-colorimetric method was used for sugar-esters quantification. The method is based on breaking the ester-bonds between the sugar moiety and the fatty acids using sodium hydroxide and quantifying free glucose molecules liberated after hydrolysis. This simple, rapid, and accurate procedure can be used for screening wild tomato accessions of L. pennellii for sugar-ester contents.
Screening Wild Tomato Accessions for Sugar-Ester Contents
Both native and greenhouse populations of Lycopersicon pennellii Corr. (a wild relative of commercial tomato, L. esculentum) have sticky exudates known as sugaresters (glycolipids) covering their leaves and stems. L. pennellii resistance to important vegetable pests has been attributed primarily to type-IV glandular trichome secretions. This study was initiated to extract and quantify sugar-esters in four wild tomato accessions (PI-503516, PI-246502=LA 716, PI-365972=LA 1277, and PI414773) of L. pennellii which have long been known to entrap insect pests in their sticky exudates. Extracts of glandular trichomes containing sugar-esters were prepared in chloroform and reconstituted in ethanol. A simplified micro-colorimetric method was used for sugar-esters quantification. The method is based on breaking the ester-bonds between the sugar moiety and the fatty acids using sodium hydroxide and quantifying free glucose molecules liberated after hydrolysis. This simple, rapid, and accurate procedure can be used for screening wild tomato accessions of L. pennellii for sugar-ester contents.