关键词: 光合速率, 气孔导度, 光化学效率, 玉米

Abstract: Significant differences of photosynthetic rate (Pn) in the leaves of two maize (Zea mays) strains (‘Shuang 105’ and ‘40×44’) growing in the field were observed. Compared with the strain of ‘Shuang 105’, the strain of ‘40×40’ had higher Pn, higher photo-chemical efficiency of PS Ⅱ (Fv/Fm and △F/Fm') at different development stages. Meanwhile, it had better plant height and leaf area, but it's content of chlorophyll was lower. According to the results of the experiment, ‘Shuang 105’ had higher concentration of intercellular CO₂ (Ci) though it had lower stomatal conductance (Gs) and Pn. Hence, the differences in Pn between the two strains did not result from the difference in Gs, but probably from that in light reaction system.

Key words: photosynthetic rate, stomatal conductance, photochemical efficiency, maize