Abstract
To investigate the effects of water withholding on 17 tomato (Solanum lycopersicum L.) landraces collected from different climatic zones of Iran and two commercial hybrids, the polyphasic OJIP fluorescence transient, relative water content (RWC), electrolyte leakage (EL) and vegetative growth parameters were analyzed. Duncan’s multiple range test (DMRT) for all the studied parameters and drought factor index (DFI) based on performance index on the absorption basis (PIabs) were used for screening the plants based on their tolerance to drought condition. Result showed that compared to the control plants, vegetative growth parameters, RWC, PIabs, relative maximal variable fluorescence (FM/F0), maximum quantum efficiency of PSII (FV/FM), quantum yield of electron transport (ΦE0) and electron transport flux per reaction center (RC) (ET0/RC) were decreased, whereas, EL, quantum yield of energy dissipation (ΦD0), specific energy fluxes per RC for energy absorption (ABS/RC) and dissipated energy flux (DI0/RC), which are closely related to the incidence of photoinhibition were increased in plants exposed to water withholding. DMRT and DFI screening results clearly categorized the landraces into three groups (tolerant, moderately sensitive and sensitive). Tolerant landraces showed less change for most of the measured parameters compared to sensitive and moderately sensitive landraces. We found that adapted landraces to dry climates had a higher tolerance to drought stress. Principal component analysis (PCA) revealed that FM/F0, FV/FM, ΦE0, ΦD0, PIabs, ABS/RC, ET0/RC and DI0/RC parameters are the most sensitive parameters for detection of impact of drought stress on tomato plants. In conclusion, the eight parameters have the potential to identify the drought injury in tomato seedlings.
Highlights
Tomato (Solanum lycopersicum L.), with annual global production of around 182.3 million tons, is the second top tonnage produced vegetable worldwide (FAOSTAT 2018)
The highest D WShoot, DWRoot, FWRoot, VRoot, number of leaves and the tallest plants were observed in control plants
Many research teams all around the world are focusing on issues related to the impacts of drought stress on crop yields and food security
Summary
Tomato (Solanum lycopersicum L.), with annual global production of around 182.3 million tons, is the second top tonnage produced vegetable worldwide (FAOSTAT 2018). Tomato is not categorized as a tolerant plant in response to many abiotic stress conditions and its growth and productivity is limited by unfavorable environmental conditions such as drought and salinity (Dong et al 2020). Drought stress has diverse negative effects on tomato during its ontogeny (Jiang et al 2019). In general plant susceptibility to drought depends on the genotype, timing and intensity of the imposed stress (Aliniaeifard and Van Meeteren 2016a, b). Drought stress causes many adverse effects including negative leaf water balance, turgor loss, chlorophyll (Chl) degradation and down-regulation of photosynthesis through affecting stomatal functioning and restricting supply of carbon dioxide (Zhou et al 2017).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
