EFFECTS OF ALUMINUM ON SEED GERMINATION AND INITIAL GROWTH OF PHYSIC NUT SEEDLINGS

Abstract

A luminum (Al 3+ ) toxicity is one of the major factors that limit plant growth and crop yield in acid soils. The phytotoxic effects of aluminum on seed germination and initial growth of physic nut ( Jatropha curcas L.) seedlings were investigated in the present study. Physic nut seeds were subjected to five levels of aluminum [0 (control), 20, 40, 60 and 80 mg L –1 ], using the solution-paper method, with eight replications. The experimental unit consisted in a germitest paper roll with 25 physic nut seeds. Treatments were evaluated based on the following tests: first count of germination test (7 days), total germination (12 days) and initial growth of physic nut seedlings (12 days). The addition of 80 mg L –1 of Al reduced the first count of germination test (7 9 %), total germination ( 90 %), s hoot length ( 20 %), shoot dry matter ( 30 %), root length ( 76 %) and root dry matter ( 83 %) of physic nut seedlings compared to the Al-free control. The addition of high concentrations of Al severely restricted the seed germination and initial growth of physic nut seedlings . Phytotoxic effects of Al is more accentuated on the root growth than on shoot growth of physic nut seedlings . The data presented here suggest that the physic nut is a susceptible species to high concentrations of Al during the phase of seed germination and early growth. Normal 0 21 false false false PT-BR X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:Tabela normal; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:Calibri,sans-serif; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:Times New Roman; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Times New Roman; mso-bidi-theme-font:minor-bidi;}