<b>Effect of salinity and priming on seedling growth in rapeseed (<i>Brassica napus</i> var <i>oleifera</i> Del.)</b> - doi: 10.4025/actasciagron.v35i4.17655

Abstract

ABSTRACT. Experiments were performed to examine the effect of salt stress and GA 3 -priming on initial growth of two rapeseed cultivars, one tolerant and one sensitive to salt stress during germination. Seedlings from seeds germinated in salty (as NaCl) and non salty substrate were grown in salty and non salty hydroponics. Salt stress reduced seedling growth of the two genotypes consistently with their degree of stress tolerance during germination. Seedlings from stress sensitive seeds germinated under high salinity showed a rapid recover of growth in non stressing conditions. The effect of salt stress on shoot/root ratio was controversial, increased for lab and decreased for greenhouse experiments, probably due to different timing of stress application and additional experimental conditions. Salt stress decreased leaf photosynthesis and increased thermal dissipation in sensitive seedlings (decrease of ΦPSII and qP, increase of NPQ). The GA 3 -priming did not affect seedling growth of the stress sensitive cultivar subjected to stress, while it greatly improved the performance of the stress tolerant cultivar.Keywords: NaCl, GA 3 , root, shoot, fluorescence, stomatal conductance.Efeito da salinidade e condicionamento osmótico sobre o crescimento das plântulas em colza (Brassica napus var oleifera Del.) RESUMO. Os experimentos foram realizados para examinar o efeito de sal e o período de condicionamento osmótico do GA 3 sobre o crescimento inicial de duas cultivares de colza, sendo uma tolerante e uma sensível ao estresse salino durante a germinação. As mudas provenientes de sementes germinadas em meio salino (como NaCl) e não salgado foram cultivadas em hidroponia na presença ou ausência de salinidade. O estresse salino reduziu o crescimento das plântulas dos dois genótipos de forma consistente com o seu grau de tolerância ao estresse durante a germinação. As mudas provenientes de sementes sensíveis germinadas sob alta salinidade mostrou uma recuperação rápida do crescimento em condições não estressantes. O efeito do estresse salino sobre relação parte aérea / raiz foi controverso, aumentando em condições laboratoriais e diminuindo para os experimentos em casa de vegetação, provavelmente devido a épocas de estresse e outras condições experimentais. O estresse salino reduziu a fotossíntese foliar e aumentou a dissipação térmica em mudas sensíveis (queda de ΦPSII e qP, aumento do NPQ). O condicionamento osmótico do GA 3 não afetou o crescimento das plântulas da cultivar sensível estresse submetido ao estresse, ao mesmo tempo que melhorou significativamente o desempenho da cultivar tolerante estresse.

Deciphering priming-induced improvement of rapeseed (Brassica napus L.) germination through an integrated transcriptomic and proteomic approach

“…This gives the opportunity that the results obtained for rape can be directly applied to overcome problems faced in agricultural practices [10]. Recently published studies demonstrated that seed priming clearly improves the germination phase in this species under both optimal and adverse conditions [23,24,25].…”

The Proteome Response of Salt-Sensitive Rapeseed (Brassica napus L.) Genotype to Salt Stress

“…Since soil and water salinity are the most important limiting factors of Rapeseed production, breeding and using the tolerant genotypes to salt stress can be a good strategy to preserve the production levels in the face of salinity stress (Ashraf and Akram, 2009). Salinity reduces or delays the germination of most crops (Farhoudi and Sharifzadeh, 2006;Benincasa et al, 2013). It also reduces some traits such as root length, shoot height, root and shoot dry weight and leaf area index at seedling stage (Miyamoto et al, 2012;Haq et al, 2014).…”

Domestication influences morphological and physiological responses to salinity in Brassica oleracea seedlings

“…Salt particularly influences growth processes, so that growth rates and biomass production are reliable criteria for assessing the degree of salt stress in a plant and its salt-tolerance capacity (Flowers and Flowers 2005). In addition, changes in biomass allocation may be determinant in salt tolerance (Byrt and Munns 2008), and shoot growth is generally more salt-sensitive than root growth (Munns 2002; Benincasa et al 2013). It can be assumed that a reduction in leaf area relative to root growth will decrease water uptake, thus conserving soil moisture and preventing osmotic stress due to the salt concentration (Munns and Tester 2008).…”