Natural Products: Seasonal Variation in Trichome Counts and Contents in Lycopersicum hirsutum f. glabratum

Abstract Wild tomato leaves possess a pest-resistance mechanism in their glandular trichomes and the exudates they produce. Type IV and VI glandular trichomes on the leaves of five wild tomato accessions of Lycopersicum hirsutum f. glabratum (PI 126449, PI 134417, PI 134418, PI 251304, and LA 407) grown under greenhouse conditions were counted. Major chemical compounds from glandular leaf trichomes of the accessions tested were extracted, purified, and quantified at different periods during the growing seasons by gas chromatography (GC) and mass spectrometry (GC/MS). The toxicity of two methylketones (2-undecanone and 2-tridecanone), the major constituents of the accessions tested, to adults of the sweetpotato whitefly, Bemisia tabaci (Gennadius) and fourth instar larvae of the Colorado potato beetle (CPB), Leptinotarsa decemlineata (Say), was determined using no-choice bioassays. 2-undecanone caused 80% mortality of the fourth instar larvae of the CPB at the highest concentration tested (100 mg 2-undecanone mL− 1 of acetone) while 2-tridecanone caused 72% mortality of whiteflies at 20 mg 2-tridecanone mL− 1 of 65% ethanol. The concentration of 2-undecanone and 2-tridecanone on the leaves of each of the five accessions of L. hirsutum f. glabratum and the mass spectra of 2-undecanone and 2-tridecanone are presented. Overall, the concentration of 2-undecanone on the leaves was significantly higher than 2-tridecanone. Concentration of the two methylketones varied among accessions and sampling season. Plants produced the highest concentration of 2-undecanone during the month of August. On average, each plant of accession PI 251304 provided 354 g fresh leaves (averaging about 52,353 cm2 exposed leaf surface area) and produced 32.5 and 8.7 mg of 2-undecanone and 2-tridecanone, respectively. L. hirsutum f. glabratum accessions may become a valuable source of natural products, which could minimize reliance on synthetic pesticides.

[1]  R. Mumma,et al.  Effects of mite resistance mechanism of geraniums on mortality and behavior of foxglove aphid (Acyrthosiphon solani Kaltenbach) , 1990, Journal of Chemical Ecology.

[2]  J. Kumamoto,et al.  Activity of volatile compounds in glandular trichomes ofLycopersicon species against two insect herbivores , 1987, Journal of Chemical Ecology.

[3]  G. Antonious.  Persistence of 2-Tridecanone on the Leaves of Seven Vegetables , 2004, Bulletin of environmental contamination and toxicology.

[4]  Maurice W. Sabelis,et al.  Toxicity of methyl ketones from tomato trichomes to Tetranychus urticae Koch , 1997, Experimental & Applied Acarology.

[5]  J. Goodman,et al.  2,3-Dihydrofarnesoic acid, a unique terpene from trichomes ofLycopersicon hirsutum, repels spider mites , 1993, Journal of Chemical Ecology.

[6]  G. Antonious,et al.  Insecticidal and Acaricidal Performance of Methyl Ketones in Wild Tomato Leaves , 2003, Bulletin of environmental contamination and toxicology.

[7]  G. Antonious,et al.  Zingiberene and Curcumene in Wild Tomato , 2003, Journal of environmental science and health. Part. B, Pesticides, food contaminants, and agricultural wastes.

[8]  F. Morales.  Conventional breeding for resistance to Bemisia tabaci-transmitted geminiviruses☆ , 2001 .

[9]  John C. Palumbo,et al.  Insecticidal control and resistance management for Bemisia tabaci , 2001 .

[10]  Thomas J. Henneberry,et al.  History, current status and collaborative research projects for Bemisia tabaci , 2001 .

[11]  G. Antonious.  PRODUCTION AND QUANTIFICATION OF METHYL KETONES IN WILD TOMATO ACCESSIONS , 2001, Journal of environmental science and health. Part. B, Pesticides, food contaminants, and agricultural wastes.

[12]  R. Nauen,et al.  Resistance of Bemisia tabaci (Homoptera: Aleyrodidae) to insecticides in southern Spain with special reference to neonicotinoids. , 2000 .

[13]  G. Antonious,et al.  Tomato cultivar susceptibility to Egyptian cotton leafworm (Lepidoptera: Noctuidae) and Colorado potato beetle (Coleoptera: Chrysomelidae) , 1999 .

[14]  E. Grafius.  Economic impact of insecticide resistance in the Colorado potato beetle (Coleoptera: Chrysomelidae) on the Michigan Potato Industry , 1997 .

[15]  D. Hannapel,et al.  Novel mechanism for resistance to Colorado potato beetle (Coleoptera: Chrysomelidae) in wild Solanum species , 1997 .

[16]  A. Simmons.  Oviposition on Vegetables by Bemisia tabaci (Homoptera: Aleyrodidae): Temporal and Leaf Surface Factors , 1994 .

[17]  G. Antonious,et al.  Trichome density and pesticide retention and half‐life , 1993 .

[18]  J. Mudd,et al.  Epicuticular Lipid Accumulation on the Leaves of Lycopersicon pennellii (Corr.) D'Arcy and Lycopersicon esculentum Mill. , 1985, Plant physiology.

[19]  G. Kennedy,et al.  THE ROLE OF GLANDULAR TRICHOMES IN THE RESISTANCE OF LYCOPERSICON HIRSUTUM F. GLABRATUM TO HELIOTHIS ZEA , 1983 .

[20]  G. Kennedy,et al.  2-TRIDECANONE: A NATURAL TOXICANT IN A WILD TOMATO RESPONSIBLE FOR INSECT RESISTANCE , 1983 .