INVESTIGADORES
RUBIO Gerardo
congresos y reuniones científicas
Título:
Phosphorus availability does not affect the root to shoot allometric relationship
Autor/es:
RUBIO G. AND M. C. FERNANDEZ
Lugar:
Sacramento, California
Reunión:
Simposio; XVI International Plant Nutrition Colloquium en Sacramento, California.; 2009
Institución organizadora:
International Plant Nutrition
Resumen:
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Abstract: Allometrics is an
useful tool to evaluate biomass allocation among different plant organs. It is
based in the logarithmic relationships between biomass partitioned to two plant
organs (e.g. root to shoot). An increase in the root to shoot ratio is a common
plant response to phosphorus deprivation. In this work, we tested the
hypothesis that the root to shoot ratio is mainly determined by the total size
of the plant rather than by soil phosphorus availability. We performed a field
and a greenhouse experiment in which soybean, sunflower and maize were grown
under a range of soil phosphorus levels. In successive harvests we measured the
root and shoot biomass accumulation and calculated KRMA, which is
the slope of the log shoot biomass log root biomass plot, divided by the
correlation coefficient r. Allometric biomass partitioning between root and
shoot in the field was very similar with that found in the greenhouse
experiment. The root to shoot allometric coefficient did not differ
statistically among phosphorus treatments in the three evaluated crops. We
consistently observed that the allometric coefficients were not significantly
different among the three species, Allometric coefficients KRMA were 0.91, 0.89 and 0.94 for soybean,
sunflower and maize, respectively (average of all phosphorus treatments and
both experiments). Obtained results allowed us to accept the proposed
hypothesis and to conclude that the root to shoot ratio was determined by the
total size of the plant and the phosphorus supply level did not modify this
ratio.