Efeito do estresse salino na absorção de nutrientes em mangueira

Abstract

Avaliou-se o efeito do estresse salino sobre a massa seca, a absorção e o transporte de nutrientes nas mangueiras 'Haden', 'Palmer', 'Tommy Atkins' e 'Ubá' enxertadas sobre 'Imbu'. Foi utilizada solução nutritiva de Hoagland modificada em sistema hidropônico estático aerado, contendo: 0; 15; 30 e 45 mmol L-1 NaCl. A massa seca de raízes, caule do porta-enxerto e caule da cultivar copa, bem como das folhas, foi reduzida em concentrações a partir de 15 mmol L-1 NaCl. Ocorreu redução de N, P, K+, Ca+2 e Mg+2 nas folhas de 'Haden', 'Palmer' e 'Ubá', respectivamente. 'Tommy Atkins' não apresentou variação no teor de N, P, K+ e Ca+2 foliar. No sistema radicular, os teores de N, P, K+, Ca+2 e Mg+2 foram reduzidos com o aumento de NaCl em todas as cultivares. A concentração externa do íon Na+ reduziu os sítios de absorção de K+ e Mg+2, e o íon Cl- atuou nos sítios de absorção de N e P, inibindo sua absorção devido a mecanismos competitivos.

Morpho-physiological adaptation of Jatropha curcas L. to salinity stress

“…curcas plants also showed decreased effective PSII quantum yield due to salinity increase in consequence of the negative effect of salt stress on the photosynthesis apparatus. Actually, several studies involving different plant species such as Ricinus communis L. (Li et al, 2010) and Mangifera indica L. (De Lucena et al, 2012) have shown that the PSII effective quantum yield progressively decreases when the salt content in soil solution increases.…”

Development of mango wilt in mango cultivars submitted to salt stress

“…In Brazil, the use of mango cultivars showing high level of basal resistance against C. fimbriata infection has been the most effective control strategy mainly because of a failure in the use of pesticides (Ribeiro 2005;Rossetto et al 1996;Viégas 1960). Some mango cultivars showing greater resistance to mango wilt are at the same time very sensitive to salt stress (Lucena et al 2012). For example, Tommy Atkins and Ubá cultivars, considered to be resistant to mango wilt (Araujo et al 2014;Rossetto et al 1996), are tolerant and sensitive, respectively, to salt stress (Lucena et al 2012).…”

“…Some mango cultivars showing greater resistance to mango wilt are at the same time very sensitive to salt stress (Lucena et al 2012). For example, Tommy Atkins and Ubá cultivars, considered to be resistant to mango wilt (Araujo et al 2014;Rossetto et al 1996), are tolerant and sensitive, respectively, to salt stress (Lucena et al 2012).…”

“…The number of cultivated areas suffering from salinity around the world has dramatically increased nowadays (Lucena et al 2012;Zuazo et al 2003;Zuazo et al 2004;Zuazo et al 2006) and it affects many important physiological processes on plants such as photosynthesis, synthesis of protein, and lipid metabolism (Carillo et al 2011). According to Zuazo et al (2003), Zuazo et al (2004), and Zuazo et al (2006), many mango cultivars sensitive to salinity when grown in saline soils show the apex or the edges of the leaves burned, reduction in growth, leaf abscission, and further plant death, and, for some pathosystems, the host defense responses against pathogens infection are negatively impaired (Bartels and Sunkar 2005;Dileo et al 2010;Maurya and Gothandam 2014).…”

“…After disease evaluation, longitudinal stem sections containing the inoculation point at the center were collected from plants from the replications of each treatment to determine the concentrations of sodium (Na) and chlorine (Cl) according to Noguchi and Kamiya (1963) and Lucena et al (2012). The stems were dried at 65 °C for 72 h and grounded in a Thomas-Wiley mill with a 20-mesh sieve.…”