Salt sensitivity in chickpea (Cicer arietinum L.): ions in reproductive tissues and yield components in contrasting genotypes

Abstract

The reproductive phase in chickpea (Cicer arietinum L.) is affected by salinity, but little is known about the underlying cause. We investigated whether high concentrations of Na(+) and Cl(-) in the reproductive structures influence reproductive processes. Chickpea genotypes contrasting in tolerance were subjected to 0, 35 or 50 mm NaCl applied to soil in pots. Flower production and abortion, pod number, percentage of empty pods, seed number and size were evaluated. The concentrations of Na(+) , K(+) and Cl(-) were measured in various plant tissues and, using X-ray microanalysis, in specific cells of developing reproductive structures. Genotypic variation in reproductive success measured as seed yield in saline conditions was associated with better maintenance of flower production and higher numbers of filled pods (and thus seed number), whereas seed size decreased in all genotypes. Despite the variation in reproductive success, the accumulation of Na(+) and Cl(-) in the early reproductive tissues of developing pods did not differ between a tolerant (Genesis836) and a sensitive (Rupali) genotype. Similarly, salinity tolerance was not associated with the accumulation of salt ions in leaves at the time of reproduction or in seeds at maturity.

Differential growth and yield responses of salt-tolerant and susceptible rice cultivars to individual (Na+ and Cl−) and additive stress effects of NaCl

“…Reproductive phases are considered very important and crop yields and quality is largely dependent on them, but unfortunately the process of reproductive development and grain quality is affected by salinity mostly due to impaired transport of photosynthates to the grain filling site (Kotula et al 2015).…”

Salt sensitivity in chickpea: Growth, photosynthesis, seed yield components and tissue ion regulation in contrasting genotypes

“…'Exclusion' of Na + is an important mechanism for plants in saline substrates to maintain reasonable leaf Na + concentrations and avoid toxicity to photosynthetic tissues (Munns and Tester, 2008); however we observed that both Na + and Cl − in green leaves or stems of the sensitive genotype (Rupali) were similar or lower compared to those in the tolerant genotypes (JG11 and Genesis836), indicating that ion 'exclusion' does not explain the differences in salt tolerance between these genotypes. A recent study, also having Rupali and Genesis836 when grown in saline soil in pots, also found that salinity tolerance is not linked with genotypic differences in leaf Na + and Cl − concentrations (Kotula et al, 2015). So, it is further hypothesized here that differences in 'tissue tolerance' (of Na + and/or Cl − ) could contribute to the differences in salt tolerance in these chickpea genotypes; as evidenced by higher maintenance of photosynthesis, less leaf damage symptoms (own observations) and greater leaf dry mass in Genesis836 while leaf Na + and Cl − concentrations were similar in the three genotypes (Table 2, Fig.…”

“…The reproductive tissues/processes of JG11 might be particularly salt sensitive (Samineni et al, 2011). However for chickpea (Rupali and Genesis836) in salinized soil, only low concentrations of Na + and Cl − were found in reproductive tissues soon after fertilisation of the ovary (Kotula et al, 2015).…”

Inducing salt tolerance in castor bean through seed priming

“…Nevertheless, NaNO 3 priming alleviated the salinity effect and promoted a reduced K + /Na + content ratio in the roots by reducing the K + content as well as saltresistant species (Fig 8c, e). Therefore, the action of effective priming treatments such as NaNO 3 reaffirms that salinity tolerance is related not only to the presence of higher levels of Na + in the tissue but also to the tolerance of the tissue itself, as highlighted by Khan et al (2015) and Kotula et al (2015).…”