广西4个种源蚬木苗木光合特性的比较

以广西4个不同种源蚬木Excentrodendron hsienmu苗为研究材料, 测定及分析其光响应曲线及光合参数日变化规律, 以期为蚬木引种和优选提供理论依据。结果表明: 武鸣种源具最高的光饱和点(LSP)和光补偿点(LCP), 具有较好的适应强光的能力。靖西种源具有较高的最大光合速率(Pmax)、LSP和斜率(AQY), 以及较低的LCP和暗呼吸速率(Rd), 因此可能具有较强的同化能力。大新种源虽LSP最低, 但其具有最高的Pmax和最低的Rd, 以及较低的LCP, 这可能也赋予了该种源具有较强的同化能力。4个种源蚬木均有明显的光合午休现象, 并且净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)、水分利用效率(WUE)在不同种源间均存在显著差异, 其中武鸣种源具有较低的Tr和较高的WUE, 靖西种源表现了较高的Gs和Tr。因此, 在相对保水性较好的赤红壤土地上种植蚬木, 可优先选择靖西和大新种源。

Comparison of photosynthesis in seedlings of Excentrodendron hsienmu from 4 provenances in Guangxi

By taking the seedlings of Excentrodendron hsienmu from four provenances as studied materials,theirs photosynthetic light response curves and were recorded and analyzed.The results showed that Wuming provenance had the highest light saturation point(LSP)and light compensation point(LCP),presenting a good acclimatization to bright light.Jingxi provenance had higher maximum net photosynthetic rate(Pmax),LSP,and apparent quantum eff iciency(AQY)and had the lower LSP and dark respiration rate(R_d),presenting a good ability of assimilation and accumulation.Daxin provenance had the lowest LSP and R_d,and had the highest P_max,and had the lower LCP,presenting a good ability of assimilation.The Excentrodendron hsienmu from four provenances presented the‘noon depression’phenomenon.The Pn,Tr and Gs,WUE had significant differences in different provenances.Wuming provenance had the lower Tr and higher WUE.Jingxi provenance had the higher Gs and Tr.The provenances of Daxin and Jingxi could be selected when we planted the Excentrodendron hsienmu in the latosolic red soil region.