Morpho-physiological performance of Mikania glomerata Spreng. and Mikania laevigata Sch. Bip ex Baker plants under different light conditions

Abstract

ABSTRACT (Morpho-physiological performance of Mikania glomerata Spreng. and Mikania laevigata Sch. Bip ex Baker plants under different light conditions). In tropical and subtropical zones, lianas play important roles in the process of ecological succession. This study aims to evaluate the photosynthetic and morpho-physiological performance between two lianas species from Mikania genus in response to different levels of radiation: full sun (I0), 25% (I25), 50% (I50), and 75% (I75) retention of solar radiation flux. Plants grown under I75 showed a reduced net photosynthetic rate (A). We observed dynamic photoinhibition at I0 during hours of high irradiation and temperature. The highest and lowest leaf chlorophyll content occurred at I75 and I0, respectively, while carotenoids/total chlorophyll and leaf thickness increased under I0. Total dry mass was higher in plants grown at I0 and I25. However, A values and biomass production of Mikania laevigata were higher at I25, while for Mikania glomerata greater biomass accumulation was observed between I0-I50. Therefore, we concluded that M. laevigata and M. glomerata have different morpho-physiological performances under same the radiation conditions.

Keywords

• chlorophyll a fluorescence
• gas exchange
• irradiation interference
• lianas
• photosynthesis