有机种植是在生态学理论指导下的一种重要的种植体系,但是缺乏对其深入的机理研究。该试验以结果时期的黄瓜、豇豆和番茄为研究对象,测定其在有机种植条件下叶片的光合特性、叶绿素荧光参数和叶绿素相对含量等指标,研究三者叶片光合特性的特点与差异。结果表明:3种有机蔬菜叶片的叶绿素含量大小为豇豆〉黄瓜〉番茄;3种有机蔬菜的净光合速率Pn、蒸腾速率Tr和气孔导度Gs对光强的响应为:豇豆〉黄瓜〉番茄,拟合的最大净光合速率Pnmax和光饱和点LSP的大小为:黄瓜〉豇豆〉番茄,表观量子效率AQE、光补偿点LCP和暗呼吸速率Rd的大小为豇豆〉黄瓜〉番茄;PSⅡ光化学效率(Fv/Fm)和PSⅡ潜在活性(Fv/Fo)大小均为黄瓜〉豇豆〉番茄。综合以上结果得出,有机黄瓜和豇豆的叶片的光合固碳能力较强,番茄弱之。
Organic farming is an important kind of cultivation under the guidance of ecology theory. Nonetheless there is lack of the further research about its mechanisrrL The photosynthetic capability of cucumber, asparagus bean and tomato in the fruiting period were studied,as they were grown in normative organic horticulture. Photosynthetic characteristics, chlorophyll fluorescence and the relative chlorophyll content were compared between cucumber, asparagus bean and tomato under same organic growing conditions. The results showed that the value of the relative chlorophyll content of the three vegetables' leaves was asparagus bean〉 cucumber〉 tomato. The corresponding of Pn/Tr/Gs of the three organic vegetables to light intensity was asparagus bean〉cucumher〉tomato. The value of fit Pn,,x and LSP was cucumber:〉asparagus bean〉tomato. The value of AQE, LCP and Rd was asparagus bean〉 cucumber〉 tomato. The value of Fv/Frn and Fv/Fo was eucumber〉asparagus bean:〉 tomato. Based on the above results, it showed that the photosynthetic capability of the organic cucumber and asparagus were stronger than tomato's.