Quantitative developmental response to the length of exposure to long photoperiod in wheat and barley
MetadataShow full item record
The present study was designed to analyse the effect of the length of exposure to a long photoperiod imposed c. 3 weeks after sowing in spring wheat (cv. UQ189) and barley (cv. Arapiles) to (i) establish whether the response to the number of cycles of exposure is quantitative or qualitative, (ii) determine the existence of a commitment to particular stages well before the stage has been observable, and (iii) study the interrelationships between the effects on final leaf number and phyllochron when the stimulus is provided several days after seedling emergence. Both wheat and barley seemed to respond quantitatively to the number of long-day cycles they were exposed to. However, wheat showed a requirement of approximately 4 long-day cycles to be able to produce a significant response in time to heading. The barley cultivar used in the study was responsive to the minimum length of exposure. The response to extended photoperiod cycles during the stem elongation phase was due to the ‘ memory’ photoperiod effects being related, in the case of wheat, to the fact that the pre-terminal spikelet appearance phase saturated its photoperiod response well before that stage was reached. Therefore, the commitment to the terminal spikelet appearance in wheat may be reached well before this stage could be recognized. As the response in duration to heading exceeded that of the final leaf number, and the stem elongation phase responded to memory effects of photoperiod, the phyllochron of both cereals was responsive to the treatments accelerating the average phyllochron when exposed to longer periods of long days. The response in average phyllochron was due to a switch from bi-linear to linear models of leaf number v. time when the conditions were increasingly inductive, with the phyllochron of the initial (6–8) leaves being similar for all treatments (within each species), and from then on increased.
Is part ofJournal of Agricultural Science, 2003, vol. 141, núm. 2, p. 159-167
European research projects
Showing items related by title, author, creator and subject.
Influence of "historic" photoperiod during stem elongation on the number of fertile florets in wheat Miralles, D. J.; Slafer, Gustavo A.; Richards, R. A. (Cambridge University Press, 2003)Extending the duration of the late reproductive phase in wheat has been proposed as a possible avenue to improve spike fertility. There is a positive correlation between the number of fertile florets and the duration of ...
Duration of developmental phases, and dynamics of leaf appearance and tillering, as affected by source and doses of photoperiod insensitivity alleles in wheat under field conditions Ochagavía Orbegozo, Helga; Prieto, Paula; Savin, Roxana; Griffiths, Simon; Slafer, Gustavo A. (Elsevier, 2017)Variation in photoperiod sensitivity in wheat plays a major role in the crop adaptation to wide agronomic environments. Photoperiod insensitivity is provided by Ppd-Aa, Ppd-B1a and Ppd-D1a alleles. Effects of the genome, ...
Effects of ambient temperature in association with photoperiod on phenology and on the expressions of major plant developmental genes in wheat (Triticum aestivum L.) Kiss, Tibor; Dixon, Laura E.; Soltész, Alexandra; Bányai, Judit; Mayer, Marianna; Balla, Krisztina; Allard, Vincent; Galiba, Gábor; Slafer, Gustavo A.; Griffiths, Simon; Veisz, Ottó; Karsai, Ildikó (Wiley, 2017-04-20)In addition to its role in vernalization, temperature is an important environmental stimulus in determining plant growth and development. We used factorial combinations of two photoperiods (16H, 12H) and three temperature ...