Evaluating the Contribution of Growth, Physiological, and Ionic Components Towards Salinity and Drought Stress Tolerance in Jatropha curcas

Abstract

Salinity and drought stress, singly or in combination, are major environmental menaces. Jatropha curcas L. is a biodiesel plant that can tolerate long periods of drought. However, the growth performance and stress tolerance based on physical, chemical, and physiological attributes of this plant have not yet been studied. To address this question, J. curcas seedlings were grown in a completely randomized design in plastic pots filled with soil to evaluate the effects of salinity and drought stresses on growth, ionic composition, and physiological attributes. The experiment consisted of six treatments: control (without salinity and drought stress), salinity alone (7.5 dS m−1, 15 dS m−1), drought, and a combination of salinity and drought (7.5 dS m−1+ Drought, 15 dS m−1+Drought). Our results revealed that, compared with the control, both plant height (PH) and stem diameter (SD) were reduced by (83%, 80%, and 77%) and (69%, 56%, and 55%) under salinity and drought combination (15 dS m−1+Drought) after three, six, and nine months, respectively. There was 93% more leaf Na+ found in plants treated with 15 dS m−1+Drought compared with the control. The highest significant average membrane stability index (MSI) and relative water content (RWC) values (81% and 85%, respectively) were found in the control. The MSI and RWC were not influenced by 7.5 dS m−1 and drought treatments and mostly contributed towards stress tolerance. Our findings imply that J. curcas is moderately tolerant to salinity and drought. The Na+ toxicity and disturbance in K+: Na+ ratio were the main contributing factors for limited growth and physiological attributes in this plant.

MGIDI and WAASB indices: The useful approaches for selection of salt-tolerant barley genotype at the early growth and maturity stages

“…In the present study, MSI changed modestly when plants were exposed to salinity stresses relative to control conditions (Table 2). Our results validate that these traits can be the major attributes inducing towards salt tolerance, because these were less affected by salinity stress (Abrar et al 2020). Moreover, a strong correlation was observed between these physiological parameters (Fig.…”

“…However, this result is inconsistent with other reports, which have shown that salinity stress can significantly reduce the intercellular water status in plants (Qin et al 2010). The membrane stability index (MSI) is another physiological indicator that widely used to estimate potential salinity tolerance in different crops (ElBasyoni et al 2017;Abrar et al 2020;Ebrahim et al 2020). It has been reported that MSI is more effective in screening tolerant genotypes at the early growth stage (Farooq and Azam 2006), since it often affected by lipid peroxidation caused by oxidative stress that results in the production of malondialdehyde (MDA) (Ahmed et al 2013).…”

“…Salinity-induced reduction of root and shoot biomass has also been observed by several studies in wheat (Ahmadi e al. 2020), Sorghum (Rajabi Dehnavi et al 2020), barley (Ali and Abbas 2003), purging nut (Abrar et al 2020), and rice (Rasel et al 2020).…”

“…Chlorophyll as a green-colored pigment is a vital component of the photosynthetic apparatus, and its role in capturing light energy, energy transduction, and stabilization of membranes has been investigated extensively (Porcar-Castell et al 2014;Shah et al 2017;Shin et al 2020;Abrar et al 2020). The relative chlorophyll content is likely to decline under salt treatment compared with control condition.…”

Genetic gain and relationship of yield and yield attributes of mutant and cross-bred stevia (Stevia rebaudiana) genotypes

“…Chlorophyll content had a positive relationship with the rate of photosynthesis (Yeganehpoor et al 2016). According to some researchers, the change of chlorophyll content in leaves was one of plant response to drought, to minimize light absorption by chloroplasts (Anjum et al 2011;Ucar et al 2018;Abrar et al 2020). In addition, the other research stated that chlorophyll content changed can be also caused by increased environmental pressure, especially and salinity (Taïbi et al 2016;Bertoldo et al 2018;.…”