IFEVA   02662
INSTITUTO DE INVESTIGACIONES FISIOLOGICAS Y ECOLOGICAS VINCULADAS A LA AGRICULTURA
Unidad Ejecutora - UE
artículos
Título:
Sink limitations to yield in wheat: how could it be reduced?.
Autor/es:
MIRALLES DJ; SLAFER GA
Revista:
JOURNAL OF AGRICULTURAL SCIENCE
Editorial:
Cambridge University Press
Referencias:
Lugar: Cambridge; Año: 2007 vol. 145 p. 139 - 149
ISSN:
0021-8596
Resumen:
Further genetic gains in wheat yield are required to match expected increases in demand. This may
require the identification of physiological attributes able to produce such improvement, as well as the
genetic bases controlling those traits in order to facilitate their manipulation. In the present paper, a
theoretical framework of source and sink limitation to wheat yield is presented and the fine-tuning of
crop development as an alternative for increasing yield potential is discussed. Following a top-down
approach, most crop physiologists have agreed that the main attribute explaining past genetic gains in
yield was harvest index (HI). By virtue of previous success, no further gains may be expected in HI
and an alternative must be found. Using a bottom-up approach, the present paper firstly provides
evidence on the generalized sink-limited condition of grain growth, determining that for further
increases in yield potential, sink strength during grain filling has to be increased. The focus should be
on further increasing grain number per m2, through fine-tuning pre-anthesis developmental patterns.
The phase of rapid spike growth period (RSGP) is critical for grain number determination and
increasing spike growth during pre-anthesis would result in an increased number of grains. This might
be achieved by lengthening the duration of the phase (though without altering flowering time), as
there is genotypic variation in the proportion of pre-anthesis time elapsed either before or after the
onset of the stem elongation phase. Photoperiod sensitivity during RSGP could be then used as a
genetic tool to further increase grain number, since slower development results in smoother floret
development and more floret primordia achieve the fertile floret stage, able to produce a grain. Far
less progress has been achieved on the genetic control of this attribute. None of the well-known major
The phase of rapid spike growth period (RSGP) is critical for grain number determination and
increasing spike growth during pre-anthesis would result in an increased number of grains. This might
be achieved by lengthening the duration of the phase (though without altering flowering time), as
there is genotypic variation in the proportion of pre-anthesis time elapsed either before or after the
onset of the stem elongation phase. Photoperiod sensitivity during RSGP could be then used as a
genetic tool to further increase grain number, since slower development results in smoother floret
development and more floret primordia achieve the fertile floret stage, able to produce a grain. Far
less progress has been achieved on the genetic control of this attribute. None of the well-known major
2, through fine-tuning pre-anthesis developmental patterns.
The phase of rapid spike growth period (RSGP) is critical for grain number determination and
increasing spike growth during pre-anthesis would result in an increased number of grains. This might
be achieved by lengthening the duration of the phase (though without altering flowering time), as
there is genotypic variation in the proportion of pre-anthesis time elapsed either before or after the
onset of the stem elongation phase. Photoperiod sensitivity during RSGP could be then used as a
genetic tool to further increase grain number, since slower development results in smoother floret
development and more floret primordia achieve the fertile floret stage, able to produce a grain. Far
less progress has been achieved on the genetic control of this attribute. None of the well-known major
Ppd alleles seems to be consistently responsible for RSGP sensitivity. Alternatives for identifying the
AQ2 genetic factors responsible for this sensitivity (e.g. QTL identification in mapping populations) are
being considered.
AQ2 genetic factors responsible for this sensitivity (e.g. QTL identification in mapping populations) are
being considered.
alleles seems to be consistently responsible for RSGP sensitivity. Alternatives for identifying the
AQ2 genetic factors responsible for this sensitivity (e.g. QTL identification in mapping populations) are
being considered.