DENSITY AND STRUCTURE OF LEAF TRICHOMES IN Capsicum annuum and Capsicum frutescens

Abstract

Morphology and density of plant trichomes vary by species. Several studies on family Solanaceae have shown the diversity of trichomes among species and cultivated plants, but less research on density and morphology of trichomes in the genus Capsicum. The aim of this study is to determine the density and type of leaf trichomes from Capsicum annuum and C. frutescens. The structure of trichomes was observed under light microscope equipped with Dino Eye. The density of trichomes was recorded using stereo microscope as the number of trichomes per cm 2 multiplying the total area of the leaf. Glandular and non-glandular trichomes were covered on abaxial and adaxial surfaces of both species. No significant difference was observed for trichome density between adaxial and abaxial leaf surfaces within species (C. annuum, t(8) = 1.37, p= 0.21, and C. frutescens, t(8) = -0.23, p= 0.82). However, mean trichome density on the abaxial surfacesof C. annuum was significantly lower than C. frutescens (F (3,16) = 3.79, p= 0.03). The density of glandular trichomes occurred on leaf midrib of C. frutescens (8.17 + 1.22 cm -2 ) was higher than C. annuum (4.20 + 0.42 cm -2 ; t(8) = -3.74, p= 0.02). This study provides basic knowledge of leaf trichomes structure and the density of cultivated chili plants in Malaysia.