Effect of salicylic acid seed priming on morpho-physiological responses and yield of baby corn under salt stress

Abstract

Rising salinity in the arable lands is a substantial threat to crop production. Exogenously-applied salicylic acid (SA) alleviates the negative impacts of salinity on plants. A factorial pot experiment, consisted of two baby corn hybrid cultivars (PAC 571: salt-tolerant and SG 17 Super: salt-sensitive), three doses of SA (0 [hydropriming], 1, and 2 mM) applied as a seed priming material, and four levels of salinity (0.7 [control], 6, 9, and 12 dS m–1), was conducted to evaluate the impact of SA on baby corn under salt stress. Data on growth, physiological traits, cob yield, and ion content in leaf tissues were collected, which revealed that an increasing salinity level was equally detrimental for the two tested cultivars with varying intensities. At the highest salinity level (12 dS m–1), both cultivars produced no cob, and the same salinity level caused a reduction of 67%, 14%, 42%, 87%, and 37% in shoot dry matter, leaf relative water content, membrane stability index, net photosynthetic rate, and leaf potassium content, respectively, compared with the control across cultivars and SA levels. The same salinity level caused about 3-fold, 10-fold, and 6-fold increases in electrolyte leakage, free proline content, and leaf sodium content, respectively. Seed priming with SA was effective, and 1 mM provided more promising results with an increase of 43%, 45%, 5%, and 7% in root dry matter, cob yield, leaf relative water content, and free proline content at 6 dS m–1 than 0 mM SA at the same salinity level. Salt-tolerant cultivar (PAC 571) had significantly higher cob number plant–1 (30%) and cob yield (34%) than salt-sensitive cultivar (SG 17 Super) at 6 dS m–1. However, there was largely no effect of SA seed priming on other evaluated parameters at 9 and 12 dS m–1 salinity levels. Priming of seeds with 1 mM SA could be a promising approach for baby corn production under a moderate salinity level up to 6 dS m–1. However, harmful effects of extreme salinity (9 and 12 dS m–1) cannot be completely compensated for SA seed priming.