Photosynthesis and Photosynthetic Induction of Shade-tolerant Species Amorphophallus xiei under Intercropping and Monoculture Planting Patterns

Abstract:

In order to understand the effect of planting pattern on photosynthesis of Amorphophallus xiei, the photosynthesis and photosynthetic induction were studied under intercropping and monoculture planting patterns. The results showed that the net photosynthetic rate (P_n) of A. xiei under intercropping was 18.97% higher than that under monoculture and the maximum stomatal conductance (g_s-max) was 22.4% lower than that under monoculture. There were high apparent quantum yield (AQY), light saturation point (LSP), carboxylation efficiency (CE) and chlorophyll content as well as lower dark respiration rate (R_d), light compensation point (LCP) and CO₂ compensation point (Г^*) in A. xiei under intercropping. After inducted by high illumination, the photosynthetic induction state (IS) under intercropping was higher than that under monoculture. During photosynthetic induction, the time required to reach 30% and 50% of P_max were short under intercropping. There were negative relation between initial stomatal conductance (gs-initial) and the time required to reach 30%, 50% and 90% of P_max and g_s-max. Therefore, it was suggested that light utilization capicity and carbon balance of A. xiei would enhance by rising AQY and LSP and decreasing R_d and LCP under intercropping with Zea mays, and at the same time, the capacity of facula utilization increased by rapid photosynthetic induction, and thus, increasing carbon gain.