Variation in spike growth phase duration in wheat and sensitivity to photoperiod, vernalization and intrinsic earliness

E M. WHITECHURCH, G A. SLAFER & D J. MIRALLES

Journal of Agronomy and Crop Science

Blakwell Berlag

Lugar: Berlin; Año: 2007 vol. 193 p. 131 - 137

0931-2250

The stem elongation phase in wheat (Triticum aestivum (L.)) is considered critical for yield determination, a longer duration of this phase could hypothetically increase grain set and therefore yield. Genetic variation in the relative duration of the stem elongation phase having been reported, the aim was to attempt to pinpoint whether this variability was associated with sensitivity to photoperiod, vernalizing temperatures or to differences in intrinsic earliness. Pairs of cultivars identified as having different duration of the stem elongation phase (from the appearance of the first visible node to anthesis) were grown under natural (short) or extended photoperiod, with or without vernalization. Variability in the duration of this phase, in the cultivars analysed, was related to different sensitivity to photoperiod, while differences in the previous phases were due to sensitivity to both photoperiod (though different to the sensitivity of the following phase) and vernalization. Key words: developmental phases, genotypic variation, photoperiod sensitivity, vernalization sensitivity, intrinsic earliness, wheat (Triticum aestivum (L.))