Germinação e crescimento inicial de variedades de sorgo forrageiro submetidas ao estresse salino

Abstract

R E S U M OO objetivo deste trabalho foi avaliar a tolerância à salinidade de seis variedades de sorgo forrageiro a partir da porcentagem de germinação e do crescimento inicial das plântulas submetidas a seis níveis de salinidade. Utilizou-se o delineamento experimental inteiramente casualizado, em esquema fatorial 6 x 6, com quatro repetições contendo 25 sementes. Germination and initial growth of varieties of forage sorghum under saline stress A B S T R A C TThe purpose of this study was to evaluate the salt tolerance of six varieties of forage sorghum, based on germination percentage and seedling growth subjected to six salinity levels. The treatments were arranged in a completely randomized design, according to a factorial arrangement 6 x 6 with four replications containing 25 seeds. The treatments were six varieties (V) of forage sorghum [F305 (V1), BRS 655 (V2), BRS 610 (V3), Volumax (V4), 1.015.045 (V5), 1.016.005 (V6)] and six salinity levels [0 (distilled water), 2.5, 5.0, 7.5, 10.0 and 12.5 dS m -1 ]. Experiment was conducted at the Laboratory of Seed Analysis of Embrapa Semiárido in August 2012. The variables assessed were percentage of germination, shoot (PA) and root (R) length, ratio PA/R, shoot and root fresh mass, shoot and root dry mass. Salinity levels did not affect the seed germination of varieties of forage sorghum until the conductivity of 10 dS m -1 . The salinity levels between 3 and 5 dS m -1 favored the growth of shoots and roots, showing good tolerance to salinity of forage sorghum varieties, especially F305, Volumax and 1.015.045.

Emergence and biomass accumulation in seedlings of rice cultivars irrigated with saline water

“…The negative effect of saline stress ( Figure 1A) may be related to the reduction in the osmotic potential of the substrate, hampering water absorption by seeds. Subsequently, the processes of cell division and elongation are also compromised, as well as the mobilization of reserves that are essential to germination and, consequently, emergence speed index (Pereira et al, 2012;Coelho et al, 2014).…”

Establishment of Young “Dwarf Green” Coconut Plants in Soil Affected by Salts and Under Water Deficit

“…Under adverse soil salinity conditions; however, the greater root growth can induce increased absorption of Na + and Cl -ions, reaching even toxic levels to plant species, coupled with the fact that the consequent transport to shoots may impair the growth of all other plant parts (Coelho et al, 2014).…”

“…This process is associated with the excessive accumulation of salts, being routinely indicated as a direct implication of inadequate management of soil and water resources, even leading to the abandonment of such areas for becoming unsuitable for farming (Coelho et al ., 2014).…”

“…Salt stress causes progressive decrease in plant growth, possibly caused by decrease in osmotic potential and / or excessive accumulation of ions, which can induce ionic toxicity, nutritional imbalance or both (Souza et al, 2014).…”

Uso de águas salinas como alternativa na irrigação e produção de forragem no semiárido nordestino

“…Apesar das culturas do milho e do sorgo serem classificadas como moderadamente tolerantes à estresse salino, vários estudos já demonstraram reduções significativas na produção de massa seca em reposta à salinidade, com taxas de perdas variando em função de materiais genéticos e condições ambientes (Lima et al, 2011;Sousa et al, 2012;Lacerda et al, 2006;Aquino et al, 2007;Feijão et al, 2011;Coelho et al, 2014).…”