Growth, carbohydrates and associated invertase and amylase activities in castor bean and maize as affected by metribuzin and NaCl

Abstract

Growth parameters (leaf area, length of shoot and root, water content and dry matter accumulation), contents of reducing sugars and saccharose as well as activities of r and 13-amylases of castor bean and maize seedlings and adult plants supplemented with 0.5 lag g-I and 2.5 lag g-I of melribuzin either alone or in combination with 50 lag g-1 NaC1, were increased significantly whereas at high concentrations (5 and 10 lag g-l) of herbicide, an opposite response was apparent. On the other hand, polysaccharide content and invertase activity of castor bean and maize seedlings and adult plants were significantly decreased in response to low concentrations (0.5 and 2.5 lag g-l) ofmetribuzin and increased significantly at high concentrations (5 and 10 lag g-l) of the herbicide either alone or in combination with 50 lag g-1 NaC1. Total carbohydrate contents of castor bean and maize seedlings and whole plants treated with herbicide either alone or in combination with NaCI did not change significantly. Growth parameters, carbohydrate fractions contents and activities of enzymes in both castor bean and maize seedlings and whole plants treated with herbicide alone were consistently higher than those values detected in plants treated with herbicide in combination with NaCI.

Atividade da enzima nitrato redutase em milho cultivado sob diferentes níveis de adubação nitrogenada e potássica

“…Considerada uma espécie moderadamente sensível à salinidade, com o aumento da concentração de sais no meio radicular, o milho sofre redução progressiva do crescimento (FERREIRA et al, 2007). Vários trabalhos reportam os efeitos deletérios do estresse salino sobre o crescimento do milho, independentemente da variável utilizada para esta avaliação (IZZO et al, 1991;HASANEEN et al, 1994;SANEOKA et al, 1995).…”

Estresse salino em plântulas de milho: parte I análise do crescimento

“…Alberico & Cramer (1993) observaram que a AF de plântulas de milho foi um excelente indicador do efeito dos tratamentos salinos, já que a mesma foi reduzida em cerca de 45% com a adição de 80 mol m -3 de NaCl à solução nutritiva. Em adição, Hasaneen et al (1994) verificaram que o estresse salino reduziu a AF de plantas de milho em 52%. Recentemente, Saneoka et al (1995) reportaram redução na AF de plântulas de milho sob estresse salino, tendo os genótipos tolerantes apresentado AF superior aos genótipos sensíveis.…”

“…Vários trabalhos reportam os efeitos deletérios do estresse salino sobre o crescimento do milho, independentemente da variável utilizada para esta avaliação (Totawat & Mehta, 1985;Izzo et al, 1991;Hasaneen et al, 1994e Saneoka et al, 1995. Há de se ressaltar, entretanto, que as cultivares de milho produzem diferentemente quando sujeitas à salinidade (Hajibagheri et al, 1987;Alberico & Cramer, 1993;Azevedo Neto, 1997).…”

Assessment of malathion toxicity on cytophysiological activity, DNA damage and antioxidant enzymes in root of Allium cepa model

“…Application of diuron herbicide decreased soluble carbohydrates in wheat 57 while an increase in those soluble carbohydrates was noticed in soybean plants 58 . In our case possibly, pesticides arrest the germination and growth of plants by degradation of carbohydrates reserves during germination and growth 59 . It can also be suggested that sugar metabolism is very sensitive to changes in higher stress intensity.…”