Articles
COMBINED EFFECT OF NITROGEN FERTILIZATION AND PLANT GROWTH-PROMOTING BACTERIA ON GROWTH AND NITROGEN UTILIZATION BY LETTUCE PLANTS
Article number
936_43
Pages
335 – 340
Language
English
Abstract
The effect of Azospirillum + Pantoea on plant growth and the contribution of biological nitrogen fixation (BNF) by Azospirillum to the plant N budget were studied in lettuce grown at different N levels.
Plants (Lactuca sativa L. Little Gem Ferro) were grown in a growth chamber (25/15°C for a 16/8 h light/dark cycle and relative humidity of 60/80%) and treated with Biopron® (15 g containing 109 CFUg-1 Azospirillum brasilense and Pantoea dispersa), and then irrigated at four different N levels (0, 1, 3 and 7 mM NO3–). Bacteria application increased shoot weight, the shoot/root ratio, plant N concentration and N uptake, regardless of N treatment.
The effect of bacteria application on root development was dependent on N application.
The assimilation of fixed N was estimated, using the 15N natural abundance method, from the difference in δ15N values between bacteria-treated plants and non-treated plants for each NO3– level.
Significant transfer of nitrogen from BNF to the plant by Azospirillum was observed.
The extent of the contribution of BNF to the plant N budget depended on the additional NO3– supply.
The results showed that bacteria have a potential to supply a considerable amount of N to lettuce plants, as well as to stimulate plant growth.
Plants (Lactuca sativa L. Little Gem Ferro) were grown in a growth chamber (25/15°C for a 16/8 h light/dark cycle and relative humidity of 60/80%) and treated with Biopron® (15 g containing 109 CFUg-1 Azospirillum brasilense and Pantoea dispersa), and then irrigated at four different N levels (0, 1, 3 and 7 mM NO3–). Bacteria application increased shoot weight, the shoot/root ratio, plant N concentration and N uptake, regardless of N treatment.
The effect of bacteria application on root development was dependent on N application.
The assimilation of fixed N was estimated, using the 15N natural abundance method, from the difference in δ15N values between bacteria-treated plants and non-treated plants for each NO3– level.
Significant transfer of nitrogen from BNF to the plant by Azospirillum was observed.
The extent of the contribution of BNF to the plant N budget depended on the additional NO3– supply.
The results showed that bacteria have a potential to supply a considerable amount of N to lettuce plants, as well as to stimulate plant growth.
Authors
P. Flores, P. Hellín, A. López , J. Fenoll
Keywords
Azospirillum, PGPB, nitrate, biological nitrogen fixation, 15N natural abundance
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