کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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4554873 | 1628104 | 2011 | 7 صفحه PDF | دانلود رایگان |

Imaging chlorophyll fluorescence was used to study the response of greenhouse tomato grown in soilless culture to NaCl and B concentration in the irrigation water. The plants were grown in perlite with recycling nutrient solution, which was prepared with negligible concentration or 550 mg L−1 of NaCl, and 0.5 or 2.0 mg L−1 of B in the irrigation water. High B concentration resulted in evident necrosis of leaf margins. At high NaCl concentration the recycling nutrient solution was replaced more frequently than at low salinity and this resulted in lower B concentration in the root zone, thus limiting the incidence of necrotic areas in the leaves. Indeed, the severity of leaf damage was linearly related to the mean B concentration in the recycling water. In all treatments we observed a strong difference in B concentrations between marginal and central areas, the latter remaining green and viable even in condition of severe B toxicity, as indicated by the determination of chlorophyll fluorescence. A reduction of the photosynthetic activity was observed in the symptomatic areas of the leaves on the plants grown at high B concentration in the root zone as a result of reduced dissipation of the excess of excitation energy at PSII level.
Research highlights▶ The range between concentrations of B essential for growth and leading to toxicity is narrow. ▶ High B concentration resulted in evident necrosis of leaf margins. ▶ At high NaCl the incidence of necrotic areas B-induced diminished. ▶ A reduction of photosynthetic activity was observed in the symptomatic areas.
Journal: Environmental and Experimental Botany - Volume 73, November 2011, Pages 57–63