Table I.

In situ fluorescence characteristics of leaves of IR72 plants

IR72	Fv/Fm	qP	ΦPSII
FL	0.717 ±  0.010	0.443 ±  0.039	0.217 ±  0.025
2L	0.785 ±  0.011	0.514 ±  0.032	0.292 ±  0.026
3L	0.817 ±  0.002	0.901 ±  0.031	0.630 ±  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.