Influence of daylenght on trichome densities and leaf volatiles of Lycopersicon species

Trichome densities of leaflets differed on plants of Lycopersicon esculentum, L. hirsutum, L. hirsutum f. globratum and two interspecific hybrids grown under an 8-h photophase with (long days (LD)) or without (short days (SD)) a 4-h night interruption. Response to the 2 photoperiods depended on the genotype of plant and the particular type of trichome. Generally, the densities of Type IV trichomes — short, glandular trichomes having a single tip cell — were greater under SD and densities of Type VI trichomes — short, glandular trichomes with a multicellular tip — were greater under LD. Densities of Type V trichomes — short, non-glandular trichomes — did not differ between LD and SD. Quantities of 2-tridecanone and two 15-carbon compounds were not significantly altered by the night interruption.