Abstract: Lantana camara taken as test material, its photosynthetic physiological characteristics were revealed by measuring and analyzing the leaf structure, photosynthetic pigment content and chlorophyll fluorescence parameters, so as to provide reference for ornamental cultivation of Lantana camara. The results showed that the Lantana camara leaves had thick cuticle and photosynthesized tissue, the density of palisade tissue was 41.9, the ratio of palisade tissue to spongy tissue was 0.99, and the content of chlorophyll was 4.12 mg/g. The photochemical quenching coefficient (QP) and non photochemical quenching coefficient (NPQ) decreased gradually from 8:00 to 10:00, indicating that the utilization rate of light energy was gradually increased. When the light intensity increased from 190 to 1150μmol/m2·s, the relative electron transfer efficiency (ETR) continued to increase, the maximal PSII photochemical efficiency (Fv/Fm) decreased significantly, and the actual PSII photochemical efficiency Y(II) decreased slowly after a small increase, and maintained a high level when the PAR was 285-420 μmol/m2·s. The non photochemical quenching yield Y(NPQ) increased with the increase of PAR except that decreased slightly at 625 μmol/m2·s. Correlation analysis showed that there was a correlation between the anatomical structure and fluorescence parameters of Lantana camara leaves, but none of them reached a significant level; the effects of chlorophyll content on six fluorescence parameters were as follows: ETR>Y(NPQ)>Y(Ⅱ)>NPQ>qP>Fv/Fm, and chlorophyll content was positively correlated with ETR. Therefore, Lantana camara had strong photosynthetic performance and high tolerance to light intensity, which was suitable for the high temperature and strong sunshine environment.

Key words: Lantana camara, leaf structure, photosynthetic pigment, chlorophyll fluorescence parameters