Articles
Heat stress responses of grafted tomato plants
Article number
1416_5
Pages
33 – 40
Language
English
Abstract
Climate change, which increases the intensity and frequency of heat stress, significantly limits tomato production in Texas and other southwestern regions of the US. Grafting has been shown to enhance plant vigor and disease resistance of various horticultural crops, but its effectiveness in improving heat stress tolerance in tomato plants still requires in-depth investigation.
Our study aimed to evaluate the thermotolerance of ‘Celebrity’ tomato plants grafted onto the commercial ‘Maxifort’ rootstock in growth chamber, high tunnel and open field environments.
The temperature in the growth chamber was set at 38/30°C (day/night) for heat stress and 26/19°C for control, while the high tunnel and open field experiments were conducted in the spring and summer for control and heat stress treatment, respectively, in Uvalde, Texas.
In the growth chamber, ‘Maxifort’-grafted plants demonstrated greater thermotolerance, showing improved shoot biomass, total root length and surface area, leaf transpiration rate and proline content compared to self-grafted plants.
However, no significant differences were observed in root biomass, leaf total antioxidant capacity or chlorophyll fluorescence under heat stress.
In the high tunnel, fruit yield and gas exchange rates under control temperature treatments were higher in ‘Maxifort’-grafted plants compared to ungrafted controls, but no significant differences were found under heat stress conditions.
In the open field, grafted plants had significantly greater shoot biomass than ungrafted controls under heat stress, but neither treatment group produced marketable fruits due to extreme temperature conditions.
In a follow-up post-stress recovery study, leaf ascorbate peroxidase and root superoxide dismutase and catalase showed thermotolerant responses after heat stress, but no significant thermotolerant effects of grafting were observed after recovery, including in antioxidant enzyme activities.
In conclusion, the beneficial traits of grafting identified in the growth chamber did not translate to increased fruit yield in the high tunnel and open field under heat stress, suggesting that the effectiveness of tomato grafting may be limited by growth environments.
Our study aimed to evaluate the thermotolerance of ‘Celebrity’ tomato plants grafted onto the commercial ‘Maxifort’ rootstock in growth chamber, high tunnel and open field environments.
The temperature in the growth chamber was set at 38/30°C (day/night) for heat stress and 26/19°C for control, while the high tunnel and open field experiments were conducted in the spring and summer for control and heat stress treatment, respectively, in Uvalde, Texas.
In the growth chamber, ‘Maxifort’-grafted plants demonstrated greater thermotolerance, showing improved shoot biomass, total root length and surface area, leaf transpiration rate and proline content compared to self-grafted plants.
However, no significant differences were observed in root biomass, leaf total antioxidant capacity or chlorophyll fluorescence under heat stress.
In the high tunnel, fruit yield and gas exchange rates under control temperature treatments were higher in ‘Maxifort’-grafted plants compared to ungrafted controls, but no significant differences were found under heat stress conditions.
In the open field, grafted plants had significantly greater shoot biomass than ungrafted controls under heat stress, but neither treatment group produced marketable fruits due to extreme temperature conditions.
In a follow-up post-stress recovery study, leaf ascorbate peroxidase and root superoxide dismutase and catalase showed thermotolerant responses after heat stress, but no significant thermotolerant effects of grafting were observed after recovery, including in antioxidant enzyme activities.
In conclusion, the beneficial traits of grafting identified in the growth chamber did not translate to increased fruit yield in the high tunnel and open field under heat stress, suggesting that the effectiveness of tomato grafting may be limited by growth environments.
Publication
Authors
C. Lee, D.I. Leskovar
Keywords
rootstock, ‘Maxifort’, yield, antioxidant, growth chamber
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