Insecticides From Wild Tomato: Trichome Counts and Contents
Institution
Kentucky State University
Faculty Advisor/ Mentor
George F. Antonious
Abstract
Wild species of plants contain numerous non-nutritive, bioactive compounds known as “phytochemicals”. Many of these compounds cause the leaf to be less suitable for insect growth and may influence leaf palatability. A significant positive correlation was found between the intensity of wild tomato leaf trichomes (leaf hairs) and mortality of many vegetable insects. Type-IV and type-VI glandular trichomes on the leaves of three accessions of Lycopersicon hirsutum f. typicum; six accessions of Lycopersicon hirsutum f. glabratum; two accessions of Lycopersicon pennellii; and one accession of Lycopersicon pimpinellifolium were counted monthly (January to December, 2001). Crude extracts prepared from the leaves of each species were also prepared in n-hexane and chloroform, separated, purified, and quantified using GC/MSD for biochemical composition. Monthly variations in concentration of methyl ketones, sesquiterpene hydrocarbons, and sugar esters (glycolipids) were determined. Considerable variations in biochemical constituents among accessions were detected.
Insecticides From Wild Tomato: Trichome Counts and Contents
Wild species of plants contain numerous non-nutritive, bioactive compounds known as “phytochemicals”. Many of these compounds cause the leaf to be less suitable for insect growth and may influence leaf palatability. A significant positive correlation was found between the intensity of wild tomato leaf trichomes (leaf hairs) and mortality of many vegetable insects. Type-IV and type-VI glandular trichomes on the leaves of three accessions of Lycopersicon hirsutum f. typicum; six accessions of Lycopersicon hirsutum f. glabratum; two accessions of Lycopersicon pennellii; and one accession of Lycopersicon pimpinellifolium were counted monthly (January to December, 2001). Crude extracts prepared from the leaves of each species were also prepared in n-hexane and chloroform, separated, purified, and quantified using GC/MSD for biochemical composition. Monthly variations in concentration of methyl ketones, sesquiterpene hydrocarbons, and sugar esters (glycolipids) were determined. Considerable variations in biochemical constituents among accessions were detected.