Variation in Crown and Root Organic Reserves Among Lucerne Genotypes of Different Morphology and Flower Colour |
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| Authors: | F Fornasier L Pecetti E Piano |
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| Institution: | Authors' addresses: Dr F. Fornasier, Istituto Sperimentale per la Nutrizione delle Piante, via Trieste 23, 34170 Gorizia, Italy;Dr L. Pecetti (corresponding author;e-mail: ) and E. Piano, Istituto Sperimentale per le Colture Foraggere, viale Piacenza 29, 26900 Lodi, Italy |
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| Abstract: | Previous evidence indicates that differences in the concentration of underground organic reserves can drive the survival and growing ability of lucerne under cold and defoliation stresses. In order to provide the selection process with further information on compounds that may influence plant performance under grazing, we assessed variations in cold‐season concentrations of nitrogen and carbon reserves on genotypes that had been identified for morphological features that possibly enhance grazing tolerance. The selected genotypes encompassed distinct morphological patterns (defined as ‘models’) and different taxa within the Medicago sativa complex, as shown by different flower colours. Crown concentrations of reserves were determined on 90 genotypes, whereas root concentrations were measured on a subsample of 15 genotypes. Wide intergenotypic variation was observed for all reserve substances. Comparisons among models and among flower colour classes highlighted the high concentrations of crown carbohydrates and root and crown‐soluble proteins of the model coded as ‘D1’, characterized by prostrate, rhizomatous habit and long dormancy, which largely corresponded to plants with yellow or variegated flowers, typical of ssp. falcata and × varia, respectively. There was a strong ‘flower colour × storage organ’ interaction for sugar concentration, and the results suggested a preferential compartment of sugars in the roots of purple‐flowered genotypes that belonged to the ssp. sativa. A rank correlation analysis indicated a positive relationship between persistence after two years under grazing of half‐sib progenies deriving from 19 genotypes out of the 90 and crown concentrations of carbohydrates of the 19 mother plants. |
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| Keywords: | carbon reserves crown grazing Medicago sativa L complex nitrogen reserves roots |
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