INVESTIGADORES
MADDONNI Gustavo Angel
congresos y reuniones científicas
Título:
Intra-specific competition in maize : kernel growth of extreme plant hierarchies.
Autor/es:
TANAKA, W. AND MADDONNI, G.A
Lugar:
Seattle, Washington
Reunión:
Congreso; ASA, CSSA, SSSA Annual Meeting; 2004
Institución organizadora:
ASA, CSSA, SSSA
Resumen:
In maize (Zea mays L.) there is little information of plant hierarchy effect on grain
growth. The objective of our research was to analyze the evolution of kernel weight
and their fractions (i.e. pericarp, endosperm and embryo) of extreme plant
hierarchies. Two hybrids of contrasting response to crowing (tolerant: DK752 and
susceptible: DK765) were cropped at a supra-optimal population density. Final
kernel weight and kernel fractions did not differ among hierarchies neither among
hybrids (ca. 243 mg). The lag phase of both hybrids concluded 177 degree days
after female flowering, and the shorter effective grain filling period of DK765 was
compensated with it higher effective grain filling rate (0.042 vs 0.038 mg per each
100 degree days).The pericarp growth dynamic did not differ among hybrids,
beginning near flowering and concluding at 430 degree days after flowering, when
grains normally present their maximum water content. Both the endosperm and the
embryo began to grow at 210 degree days after flowering, and concluded at
physiological maturity, but endosperm presented a constant relative rate of growth
(i.e. to the maximum weight of the endosperm) in comparison with the bi-phase
evolution of embryo growth. In future works the chemical composition of the
different fractions of the grain will be analyzed.