measured parameters were affected by field dodder parasitism from the 1st day after
infestation. An exception is the parameter F v , whose lower value in infested plants
was recorded on the 5th day after infestation (Table 1). The stressful influence of
field dodder on alfalfa and sugar beet plants caused reductions in the parameters such
as F v , F v /F m , Ф PSII , and IF. These findings are consistent with report from Vrbnicanin
et al. [86] confirming lower values of these parameters in plants exposed to stress
caused by various factors. They reported that several chlorophyll fluorescence
parameters (Fv, F v /F m , and Ф PSII ) of the host Ambrosia trifida were influenced by
the parasitism of C. campestris. One of the possible reasons could be that, in host
plant, field dodder suppressed photosynthesis by limiting gas diffusion over stomatal
and photosynthetic metabolic processes. Furuhashi et al. [87] found that photosynthetic activity in Momordica charantia stems parasitized by Cuscuta fell with time,
although values in leaves were not influenced by parasitization. As F v /F m - and F v
0 /
F m
0 - values decreased, the PSII is probably mainly affected by parasitization. It is
necessary to consider the impacts of Cuscuta infection on host plant’s photosynthesis in the context of environmental factors. Also, many studies [88, 89] have shown
Table 1 Chlorophyll fluorescence in noninfested (N) and infested (I) sugar beet and alfalfa plants
Days after infestation in the plant sugar beet
Parameters
1
5
10
15
20
Fv/Fm
N
0.7752
0.7621
0.7602
0.791
0.7963
I
0.7385
0.685
0.6505
0.753
0.7093
Ф PSII
N
0.7914
0.7926
0.7892
0.7923
0.7933
I
0.748
0.6322
0.7313
0.7777
0.7013
Fo
N
0.5446
0.5379
0.5459
0.5582
0.559
I
0.575
0.5555
0.6769
0.5847
0.5954
Fv
N
2.0446
1.9655
2.0033
2.0297
2.0317
I
1.4341
1.2971
1.3786
1.6165
1.4712
IF
N
1.1185
1.1009
1.1477
1.0771
1.1213
I
0.8693
1.3835
0.9083
0.9280
1.3331
Days after infestation in the plant alfalfa
Parameters
1
5
10
15
20
Fv/Fm
N
0.8
0.8
0.7972
0.8104
0.813
I
0.7542
0.7322
0.6482
0.7584
0.7842
Ф PSII
N
0.782
0.8098
0.7862
0.775
0.782
I
0.7568
0.6922
0.7376
0.8002
0.7568
Fo
N
0.4908
0.4908
0.504
0.4738
0.4738
I
0.5638
0.5832
0.5508
0.5508
0.571
Fv
N
2.0072
1.9266
2.044
2.0842
2.0378
I
1.9942
1.8342
1.8686
1.182
1.6182
IF
N
1.1783
1.1198
1.2124
1.1697
1.0600
I
1.1039
1.2726
0.9487
1.1209
0.9040
Fm maximal fluorescence, Fo minimum fluorescence, Fv variable fluorescence, Fv/Fm maximum
quantum efficiency of photosystem II, IF intensity of fluorescence, Ф PSII effective fluorescence
yield of photosystem II
5 Field Dodder: Life Cycle and Interaction with Host Plants
111
infestation. An exception is the parameter F v , whose lower value in infested plants
was recorded on the 5th day after infestation (Table 1). The stressful influence of
field dodder on alfalfa and sugar beet plants caused reductions in the parameters such
as F v , F v /F m , Ф PSII , and IF. These findings are consistent with report from Vrbnicanin
et al. [86] confirming lower values of these parameters in plants exposed to stress
caused by various factors. They reported that several chlorophyll fluorescence
parameters (Fv, F v /F m , and Ф PSII ) of the host Ambrosia trifida were influenced by
the parasitism of C. campestris. One of the possible reasons could be that, in host
plant, field dodder suppressed photosynthesis by limiting gas diffusion over stomatal
and photosynthetic metabolic processes. Furuhashi et al. [87] found that photosynthetic activity in Momordica charantia stems parasitized by Cuscuta fell with time,
although values in leaves were not influenced by parasitization. As F v /F m - and F v
0 /
F m
0 - values decreased, the PSII is probably mainly affected by parasitization. It is
necessary to consider the impacts of Cuscuta infection on host plant’s photosynthesis in the context of environmental factors. Also, many studies [88, 89] have shown
Table 1 Chlorophyll fluorescence in noninfested (N) and infested (I) sugar beet and alfalfa plants
Days after infestation in the plant sugar beet
Parameters
1
5
10
15
20
Fv/Fm
N
0.7752
0.7621
0.7602
0.791
0.7963
I
0.7385
0.685
0.6505
0.753
0.7093
Ф PSII
N
0.7914
0.7926
0.7892
0.7923
0.7933
I
0.748
0.6322
0.7313
0.7777
0.7013
Fo
N
0.5446
0.5379
0.5459
0.5582
0.559
I
0.575
0.5555
0.6769
0.5847
0.5954
Fv
N
2.0446
1.9655
2.0033
2.0297
2.0317
I
1.4341
1.2971
1.3786
1.6165
1.4712
IF
N
1.1185
1.1009
1.1477
1.0771
1.1213
I
0.8693
1.3835
0.9083
0.9280
1.3331
Days after infestation in the plant alfalfa
Parameters
1
5
10
15
20
Fv/Fm
N
0.8
0.8
0.7972
0.8104
0.813
I
0.7542
0.7322
0.6482
0.7584
0.7842
Ф PSII
N
0.782
0.8098
0.7862
0.775
0.782
I
0.7568
0.6922
0.7376
0.8002
0.7568
Fo
N
0.4908
0.4908
0.504
0.4738
0.4738
I
0.5638
0.5832
0.5508
0.5508
0.571
Fv
N
2.0072
1.9266
2.044
2.0842
2.0378
I
1.9942
1.8342
1.8686
1.182
1.6182
IF
N
1.1783
1.1198
1.2124
1.1697
1.0600
I
1.1039
1.2726
0.9487
1.1209
0.9040
Fm maximal fluorescence, Fo minimum fluorescence, Fv variable fluorescence, Fv/Fm maximum
quantum efficiency of photosystem II, IF intensity of fluorescence, Ф PSII effective fluorescence
yield of photosystem II
5 Field Dodder: Life Cycle and Interaction with Host Plants
111