Influence of cucumber mosaic virus infection on the growth response of Portulaca oleracea (purslane) and Stellaria media (chickweed) to nitrogen availability |
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Authors: | MARIE-LAURE NAVAS NATHALIE FRIESS & JACQUES MAILLET |
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Institution: | Centre d'Ecologie Fonctionnelle et Evolutive (CNRS-UPR 9056), 1919 Route de Mende, 34293 Montpellier Cedex 5, France; U.F.R. de Biologie et Pathologie Végétales, ENSA-M, Place Viala, 34060 Montpellier Cedex 2, France; To whom correspondence should be addressed. E-mail: |
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Abstract: | The study characterized the influence of cucumber mosaic virus (CMV) on the growth response of two annual weeds to nitrogen. Plants were grown individually along a N gradient from 4 to 32 mmol l?1 and data were interpreted using growth analysis. Plant biomass increased with N concentration and was significantly higher for healthy than infected plants at the two highest N concentrations. Healthy plants of Portulaca oleracea L. were characterized by lower biomass allocation to leaves and higher biomass allocation to roots than infected plants; no change in biomass allocation was recorded for Stellaria media Vill. Relative growth rate ( rgr ), net assimilation rate ( nar ) and specific leaf area ( sla ) of plants increased with increasing N concentration. Healthy plants of P. oleracea were characterized by a higher rgr and nar and a lower sla than infected plants, whereas healthy S. media had a higher rgr but a similar nar and sla or leaf weight ratio ( lwr ) compared with infected plants. The consequences of these results on the population dynamics of weeds and virus spread are discussed. |
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Keywords: | Portulaca oleracea L (purslane) Stellaria media Vill (chickweed) cucumber mosaic virus nitrogen availability growth analysis rgr |
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