Two tomato species, Lycopersicon esculentum Mill. (Line TOM 556), which contained low levels of the methyl ketone 2-tridecanone (2-TD) and Lycopersicon hirsutum Dunal var. glabratum Mill. (Line PI 134417), with high levels of 2-TD, were evaluated for identification and quantification of foliar trichomes. The experiment was carried out to identify the trichomes, based on their length and on the presence, form, cell number and cell arrangment of secretory heads, as well as to quantify glandular and non-glandular trichomes. The experimental design used for trichome number was totally randomized and the averages were compared by the Tukey test, 5%. The identification and quantification of trichomes for the two species were: a) TOM 556: Types II + III + V non-glandular trichomes (2590 cm-2 of foliar area); Type VI glandular trichome (16 cm2-); Type VII glandular trichome (138 cm-2); b) PI 134417: Types II + III + V non-glandular trichomes (140 cm-2); Type I + IV glandular trichomes (843 cm-2); Type VI glandular trichome (83 cm-2); Type VII glandular trichome (11 cm-2). High concentrations of 2-TD were associated with higher densities of glandular trichomes in both species.
Lycopersicon esculentum; tomato; trichome; allelochemic; 2-tridecanone
