Tolerância à seca de genótipos de trigo utilizando agentes indutores de estresse no processo de seleção

Abstract

Drought tolerance of wheat genotypes using stress-inducing agents during selectionThe aim of this study was to select wheat genotypes tolerant to drought by inducing water deficit using different osmotic agents. Seeds and immature embryos of eight wheat genotypes were subjected to different osmotic gradients and evaluated for shoot length, main root and total biomass production. Seeds were subjected to the osmotic agents polyethyleneglycol-6000 and mannitol in seven osmotic gradients and evaluated after 10 days. The embryos were cultured in potato medium supplemented with PEG 6000, mannitol and maltose at the concentrations of 10%, 20% and 30%, plus a control, and evaluated after 30 days of incubation. The experimental design was completely randomized and data submitted to regression analysis using the "t" test to compare the Beta values and analysis Recebido para publicação em 26/11/2010 e aprovado em 25/11/2011

Genotypic Variation on the Antioxidative Response of Cowpeacultivars Exposed to Osmotic Stress

“…The effect of different water potentials on the physiology and morphology of various species, such as common bean (CUSTÓDIO; SALOMÃO; MACHADO NETO, 2009;YAMAMOTO et al, 2014), wheat (GIROTTO et al, 2012), and sunflower (HÄTER et al, 2014) has been intensively studied in order to elucidate the effects of water deficiency, as well as the mechanisms of response to the water stress. The authors, evaluating the effect of different water potentials during germination and initial growth stages, observed a decrease in growth with an increase in water restriction, a behavior explained by the reduction in cell elongation, with a consequent increase in the synthesis of the secondary wall under water stress (CARVALHO; NAKAGAWA, 2000).…”

“…Girotto et al (2012), evaluating the behavior of wheat genotypes at different water potentials induced by PEG 6000 and mannitol, observed that at a potential of −0.4 MPa, or at more negative potentials, the growth of the seedlings decreased by at least 50%, but varied among the genotypes.…”

Disponibilidade hídrica do substrato e teor de água da semente na germinação de niger1

“…hídrico proporciona reduções significativas no rendimento das lavouras, restringindo as latitudes e os solos onde espécies comercialmente importantes podem ser cultivadas (Girotto et al 2012). Na germinação das sementes, a ocorrência do estresse hídrico atua diminuindo a velocidade e a porcentagem de germinação.…”

In vitrohaderning in different enviroment and acclimatization of microplants ofComanthera mucugensisGiul. subsp.mucugensis

“…Estes resultados podem ser atribuídos ao déficit hídrico das plantas, resultante da evaporação da água do meio de cultura no recipiente com maior aeração (algodão) em relação aos demais fechamentos testados. O défict hídrico é um importante fator limitante do crescimento e desenvolvimento da planta, levando a modificações morfológicas, bioquímicas e fisiológicas, e consequentemente afetando a sua sobrevivência (GIROTTO et al, 2012;HOMAYOUN;DALIRI;MEHRAB, 2011).…”