EFFECTS OF LIGHT INTENSITY ON LEAF STRUCTURE AND GROWTH OF MANGOSTEEN SEEDLINGS

Mangosteen (Garcinia mangostana L.) is a tropical fruit crop originating in South-east Asia, growing in humid and shaded environmental conditions. Young mangosteen seedlings were grown under 25, 40, 55 or 100% of light intensity for two years. An increase of light intensity increased the thickness of lamina resulting in an increase of palisade and spongy tissues and the stomata frequency also increased. Both chlorophyll a and b declined gradually as the light intensity increased and the average ratio was 0.808. The growth of seedlings described as leaf size, leaf number per plant, total leaf area, height, fresh weight and dry weight were dramatically reduced when exposed to 100% light intensity condition. Maximum growth was found when exposed to 40% light intensity condition. Dry weights of seedlings grown under 25, 40, 55 or 100% of light intensity were 161.7, 201.5, 150.1 and 11.7 g per plant, respectively.