Table I.

In situ fluorescence characteristics of leaves of IR72 plants

FL0.717 ±  0.0100.443 ±  0.0390.217 ±  0.025
2L0.785 ±  0.0110.514 ±  0.0320.292 ±  0.026
3L0.817 ±  0.0020.901 ±  0.0310.630 ±  0.022

Measurements were made at the FL, 2L, and 3L and taken during mid-morning and mid-afternoon when incident irradiance was greatest (as dictated by the upright leaf posture). Maximum photochemical efficiency of PSII in the dark-adapted state (F v/F m) was measured following a 10-min dark adaptation period. Photochemical quenching (qP) and quantum yield of PSII reaction centers (ΦPSII) were calculated as described in the text. Values represent means of measurements taken over a 2- to 3-d period ± se, n > 20.