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Aboveground carbohydrate and nitrogen partitioning in common vetch during seed filling

Caballero, R., Rebole, A., Barro, C., Alzueta, C., Ortiz, L.T.
Agronomy journal 1998 v.90 no.1 pp. 97-102
Vicia sativa, carbohydrate metabolism, nitrogen content, filling period, dry matter partitioning, starch, sugars, lignin, seeds, pods, leaves, stems, ripening, dietary fiber, Spain
During seed filling in annual legumes, changes in concentration of assimilates occur simultaneously with plant partitioning, leading to net changes in yield of assimilates derived from the processes of accumulation and redistribution. Field studies were conducted during two growing seasons (1991-1992 and 1992-1993) in central Spain with the objectives of determining models of change for assimilate concentrations with advancing maturity and assessing efficiency of assimilate harvest relative to seed maturation. Concentration of total N, starch, total soluble sugars (TSS), neutral-detergent fiber (NDF), acid-detergent fiber (ADF), and acid detergent lignin (ADL) were determined in plant parts (seed, pod-shell, leaf, and stem) of common vetch (Vicia sativa L.) at seven maturity stages defined as progressively higher dry matter (DM) content in the seed (200-250, 250-300, 350-450, 450-550 600-700, 700-800, and > 800 g DM kg-1 seed). Concentration of assimilates in plant parts changed over the whole seed-filling period. During the phase of rapid seed growth (from 200-250 to 450-550 g DM kg-1 seed), assimilation was dominant for starch (net gain of 1086 kg ha-1), redistribution for TSS (net loss of 104 kg ha-1), and both process were operative in total N (net gain of 193 kg ha-1). During the ripening phase (from 450 to 550 to > 800 g DM kg-1 seed), most chemical components except ADL showed a net loss. Maximum total accumulation for most mobile fractions except TSS was reached at the 450 to 550 g DM kg-1 seed maturity stage. Harvesting common vetch at this stage would represent maximum efficiency for total N and starch. Concentrations of nonstructural chemical components had a nonlinear trend while concentration of fiber fractions and lignin in vegetative structures showed a linear increasing trend over the seed filling phase of common vetch.