6. PHOTOTROPISM AND PHOTOTAXIS
293
2.00I
l.80h
1.60
1.40
1.20
1.00
0.80
0.60
0.40
0.20 h
1
1
1
r
• SINGLE DETN.
o 2-3 DETNS.
Θ 4-5 DETNS.
E 6 OR MORE DETNS.
340 360 380 400 420 440 460 480 500 520 '540
WAVELENGTH IN mM
2.00
230 240
250
300
310
320
260
270
280
290
B
WAVELENGTH IN ιημ
FIG. 13. Action spectra for the phototropism of Fhy corny ces sporangiophores. A,
Positive curvature in visible light. B, Negative curvature in ultraviolet. From Curry
and Gruen
(135b).