Literature search shows that the impact of combined salinity and ozone stress has been investigated in studies. Ten studies discuss the effects of the combined stress on the growth, yield, and physiology of several plants like chickpea, cucumber, pomegranate, rice, tomato, and wheat. Combined stress was found to affect plants more negatively than individual stress in some cases (Welfare et al. 1996, 2002, Maggio et al., 2007, Zheng et al., 2012, 2014, Gerosa et al., 2007). In other cases, the effect of combined stress was less detrimental than combined stress (Hasan 2004, Peykanpour et al., 2016, Kamal et al., 2015)
For more clarity on terminologies, like combined stress, sequential stress, and multiple individual stress, please refer to ‘Pandey et al., 2017’
Stress treatments | Plant response to stress | |||||||
---|---|---|---|---|---|---|---|---|
Type A parameters* | Type B parameter* | |||||||
Shoot dry massa | Root dry massa | No. of ears/ plant | No. of grains/ ear | 1000 grain weight | Stomatal conductance# (mmol m-2 s-1) | Net photo-synthetic rate# (µmol m-2 s-1) | Chloro-phyll a/b ratio# | |
Salinity | 11.8 | 33 | 13.7 | 19.7 | 30 | 270 | 16 | 1.64 |
Ozone | 4.8 | 42.4 | 19.3 | 22.5 | 37.8 | 251 | 14.56 | 1.11 |
Salinity and Ozone | 4.05 | 29.7 | 9.9 | 16.6 | 28.5 | 263 | 15.9 | 1.33 |
Note: Values presented in the table were calculated using the formula described below
1) ''- indicates plant parameters affected by stress that lead to high susceptibility (higher the value more the damage).
'#' - Values are presented as it is from the source article without subjecting to the calculation.
'*' - For more information on parameters classification, please refer to ‘methodology’ tab.
The bar diagram shows the net impact of combined stress compared to individual stresses over the control
Note: Bar is drawn based on ‘type A’ parameters, i.e., yield of ripe fruits. When the cursor is dragged, an interaction between two levels of stress will be shown as a negative outcome (red- indicates plants are affected to a greater extent by combined stress as compared to individual stresses) or positive outcome (green- indicates plants are less/equally affected by combined stress as compared to one or both the individual stresses).
The inference from the study: Hasan 2004 studied the impact of combined salt and ozone stress on wheat cv Giza 63. The authors observed that whereas salinity treatment caused maximum reductions in shoot biomass, root biomass was most affected by ozone. Ozone stress also had a more prominent effect on the yield parameters and stomatal conductance than salt-only and combined stress. Hasan 2004, therefore, suggested that salt ameliorates the negative impact of ozone on wheat plants. Thus, the study indicates that combined salt and ozone stress have a less detrimental impact on wheat cv Giza 63 as compared to the effect of individual stresses.
Stress treatments | Plant response to stress | ||||||||
---|---|---|---|---|---|---|---|---|---|
Type A parameters* | Type B parameter* | Type C parameter* | |||||||
Shoot dry massa | Plant height | Root length (cm) | Stomatal conductance# (mmol m-2 s-1) | Net photo-synthetic rate# (µmol m-2 s-1) | Transpiration rate# (mmol m-2 s-1) | RWC# (%) | K+/ Na+ ratio# | Leaf Proline content # (mg g-1 DW) | |
Salinity | 7.8 | 6.7 | 5.2 | 410 | 20.36 | 3.9 | 79 | 2.2 | 10 |
Ozone | 9.8 | 3.8 | 1.9 | 320 | 17.55 | 4 | 73.3 | 4.2 | 12 |
Salinity and Ozone | 59 | 23.4 | 31 | 210 | 11.26 | 2.9 | 60.5 | 0.6 | 30 |
Note: Values presented in the table were calculated using the formula described below
1) ''- indicates plant parameters affected by stress that lead to high susceptibility (higher the value more the damage).
'#' - Values are presented as it is from the source article without subjecting to the calculation.
'*' - For more information on parameters classification, please refer to ‘methodology’ tab.
The bar diagram shows the net impact of combined stress compared to individual stresses over the control
Note: Bar is drawn based on ‘type A’ parameters, i.e., yield of ripe fruits. When the cursor is dragged, an interaction between two levels of stress will be shown as a negative outcome (red- indicates plants are affected to a greater extent by combined stress as compared to individual stresses) or positive outcome (green- indicates plants are less/equally affected by combined stress as compared to one or both the individual stresses).
The inference from the study: Zheng et al., 2014 studied the impact of combined salt and ozone stress on salt-tolerant wheat cv Dekang 961. The authors observed that both individual and combined stress reduced the plant's shoot and root growth, the reductions being most significant under combined stress. The physiological parameters like stomatal conductance, assimilation rate, transpiration rate, and RWC were reduced maximally under combined stress. Thus, the study indicates that combined salt and ozone stress have a more detrimental impact on wheat cv Dekang 961 as compared to the effect of individual stresses.