Regulation of salinity tolerance in Brassica juncea (L.) introgression lines: Osmoprotectants, antioxidative molecules and ionic content

Abstract

Indian mustard [Brassica juncea (L.) Czern & Coss] is one of the most important oilseed crops worldwide yet drought and salinity stress significantly reduced its growth and yield. The research was carried out in order to test the effect of salinity on osmoprotectants (total soluble sugars, proline), antioxidant molecules (ascorbate, α-tocopherol) and ionic content from the dry sample of the leaves in introgression lines and varieties of Brassica juncea. Permanent saline plots are maintained in the field of soil sciences where different doses of sodium carbonate were given to maintain the relative sodium bicarbonate (RSC) to three levels. The results revealed the significant effect of salinity on biochemical attributes as well as on ionic content. Increase in total soluble sugars, proline, ascorbate, α-tocopherol and Na+ ion whereas rest of the ions Ca2+, Mg2+ and K+ decreased with increased salinity levels. Increased accumulation of Na+ increased the Na+/K+ ratio and decreased the K+/Na+. Significant finding among the introgression lines and varieties revealed low Na+ and high K+ correspondingly Na+/K+ low and K+/Na+ ratio. Decreased calcium and magnesium ion resulted in decline in chlorophyll content and membrane stability under saline conditions while decreased K+ concentration regulated the opening and closing of stomata thus hampering photosynthesis.

High throughput phenotyping of functional traits and key indices for selection of salt tolerant Mustard [Brassica juncea (L.) Czern & Coss] genotypes

“…Salinity imposed elevated values of Na + concentration, and penalty in K + concentration in all RILs with parents (Figures 2 and 3). At the flowering stage, the highest increment percentage of Na + and reduction percentage of K + concentrations were recorded in middle leaves (Table S2, S4 and Figures 4 and 5) similar results reported by (Priya et al, 2021). Since Na + and K + have comparable hydrated ionic radii, the transporter finds it challenging to distinguish between the two ions, thus larger Na + accumulation in the roots of salt‐sensitive parent and RILs can be related to the differential cellular entrance of ions under high salinity (Priya et al, 2021).…”

“…At the flowering stage, the highest increment percentage of Na + and reduction percentage of K + concentrations were recorded in middle leaves (Table S2, S4 and Figures 4 and 5) similar results reported by (Priya et al, 2021). Since Na + and K + have comparable hydrated ionic radii, the transporter finds it challenging to distinguish between the two ions, thus larger Na + accumulation in the roots of salt‐sensitive parent and RILs can be related to the differential cellular entrance of ions under high salinity (Priya et al, 2021). The salt tolerance at the cellular level may have been influenced by the increased internal K + concentration of the salt‐tolerant CS 56 and RILs (Volkov & Beilby 2017).…”

“…There was a significant negative association of seed yield STI with RNa indicating that RILs with low Na + concentration have high seed yield (Table S7 and Figure 5). These results are in favour of (Priya et al, 2021;Wang et al, 2022) which stated that seed yield negatively associated with the Na + concentration of different plant parts. STI of YPP showed a positively significant association with yield attributing traits STI viz., MSL, NSPP, TW, PH, SPS, SL, PBr, and SBr and growth attributing traits STI viz., USFW, BrFW, BLFW, and MLFW and photosynthetic traits STI viz., Pn, inWUE indicating that by improving these traits seed yield will be increased.…”

Effect of elevated temperature on phenology, growth, yield components and seed yield of Brassica juncea grown in temperature gradient tunnels (TGT)

“…Our study of correlation (Table 5) revealed positive association of main shoot length with average temperature under both controlled (r= 0.18) and TGT conditions (r= 0.15). In B.juncea main raceme length decreased due to high temperature caused by late planting conditions (Sharma and Sardana, 2013) and due to salinity stress (Kainat andSajad, 2021 andKannupriya et al, 2021).…”

Mitigation of salt stress in Indian mustard ( Brassica juncea L.) by the application of triacontanol and hydrogen sulfide

“… 29 However, its growth, yield, and oil production are drastically affected by salinity. 30 In the last two decades, in view of the growing reorganization of the health benefits of mustard and its present possible salt tolerance, demand for it has undoubtedly increased. A beneficial approach to reducing salt stress in B. juncea is required to meet its rising demand for the growing population.…”