Photosynthetic light response of different Machilus pauhoi provenances

Objective To study the characteristics of photosynthetic light response of Machilus pauhoi, investigate the differences in photosynthesis among different M.pauhoi provenances, and provide the theoretical basis for selective breeding and afforestation of M.pauhoi.

Method Seeds of six M.pauhoi provenances with widespread potential in Guangdong were collected from Jianou of Fujian Province (MJO), Shunchang of Fujian Province (MSC), Lechang of Guangdong Province (YLC), Renhua of Guangdong Province (YRH), Lingchuan of Guangxi Province (GLC) and Gongcheng of Guangxi Province (GGC).The photosynthetic light response curves of the seedlings were recorded, and light response parameters including maximum net photosynthesis rate (Pn_max), light compensation point(LCP), light saturation point(LSP), apparent quantum yield (AQY), and dark respiration rate (R_d) were calculated.

Result GGC provenance had the highest Pn_max(12.20 μmol·m^-2·s^-1), and the largest difference between LSP and LCP (604.60 μmol·m^-2·s^-1).MJO provenance had the lowest Pn_max(5.32 μmol·m^-2·s^-1).MSC provenance had the smallest difference between LSP and LCP.

Conclusion Among six provenances, GGC has the best capability of using low light and strong light and have the highest adaptability to light, therefore this provenance has relatively high photosynthetic potential and growth potential.Close planting or mixed planting may be feasible in the afforestation of M.pauhoi.