刨花润楠不同种源光响应曲线分析

【目的】研究刨花润楠Machilus pauhoi光合作用光响应曲线特征,比较不同种源刨花润楠光合作用的差异,为刨花润楠良种选育与造林提供一定的理论依据。【方法】以福建建瓯种源(MJO)、福建顺昌种源(MSC)、广东乐昌种源(YLC)、广东仁化种源(YRH)、广西灵川种源(GLC)、广西恭城种源(GGC)6个在广东有推广潜力的刨花润楠种源为材料,观测刨花润楠的光响应曲线特征,并计算出其最大净光合速率、光补偿点、光饱和点、表观量子效率及暗呼吸速率等光响应特征参数。【结果】广西恭城种源刨花润楠的最大净光合速率最高,达到了12.20μmol·m~(-2)·s~(-1),而且其光饱和点与光补偿点之间的差值最大,为604.60μmol·m~(-2)·s~(-1),而福建建瓯种源刨花润楠的最大净光合速率最低,仅为5.32μmol·m~(-2)·s~(-1),福建顺昌种源的光补偿点与光饱和点间差值最小。【结论】参试的6个种源刨花润楠中,广西恭城种源的刨花润楠利用弱光、强光能力和对光适应能力最强,光合潜力较大,具有较好的生长潜力;刨花润楠的造林可适度密植或营造混交林。

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 the-oretical 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 Prov-ince ( GGC) . The photosynthetic light response curves of the seedlings were recorded, and light response parameters including maximum net photosynthesis rate (Pnmax), light compensation point(LCP), light saturation point( LSP) , apparent quantum yield ( AQY) , and dark respiration rate ( Rd ) were calculat-ed.Result] GGC provenance had the highest Pnmax(12. 20 μmol·m-2·s-1), and the largest differ-ence between LSP and LCP (604. 60 μmol·m-2·s-1). MJO provenance had the lowest Pnmax(5. 32 μmol·m-2 ·s-1 ) . MSC provenance had the smallest difference between LSP and LCP.Conclusion]A-mong six provenances, GGC has the best capability of using low light and strong light and have the high-est 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.