Strategies for yield determination of bread wheat and two - row barleygrowing under different environments a comparative study
Grain yield variations in bread wheat and two-row barley are better explained by changes in grain num-ber (GN) than mean grain weight. However, the strategies for building GN are different in both species because in two-row barley the variations in GN are more frequently related to the number of spikes m−2,due to its higher tillering capacity than wheat, whereas in bread wheat both grain number spike−1and thenumber of spikes m−2contribute to the establishment of GN. The higher tillering capacity and leaf areaindex at the beginning of the crop cycle in two-row barley allows a higher radiation accumulation thanin bread wheat. We hypothesize that the higher early vigor of two-row barley, associated with its greaterleaf area exposure relative to wheat, represents an initial advantage that is capitalized at the end of thecycle as higher biomass accumulation driven by a larger GN and consequently higher grain yield. The main objective of this work was to compare different physiological traits of bread wheat and two-row barleygrowing together under different temperature and radiation conditions. We evaluated two genotypes of each species, with similar phenology, growing under four different environments without water ornutritional deficiencies. Numerical yield components, biomass, radiation interception and harvest indexwere measured. Despite no differences being observed between genotypes of bread wheat and two-rowbarley in terms of total grain yield and total grain number when exposed to different environments, eachspecies had a different strategy for establishing the final yield. Although two-row barley showed initial advantages in radiation interception, bread wheat genotypes accumulated more intercepted photosyn-thetic active radiation (iPAR) and used it in a more efficient way than two-row barley, thus allowing ahigher biomass accumulation. Both species showed a reduction in grain weight due to increases in meannight and high temperatures. Grain weight reductions were higher in bread wheat than in two-row bar-ley, and were directly associated with shortening of the duration of grain filling without consequencesfor the grain-filling rate. This suggested a direct effect of temperature on grain development rather thana growth limitation due to a lack of source.
| Main Authors: | , , , |
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| Format: | Texto biblioteca |
| Language: | eng |
| Subjects: | NUMERICAL COMPONENTS, BIOMASS ACCUMULATION, YIELD STRATEGIES, ENVIRONMENTS, NIGHT TEMPERATURE, |
| Online Access: | http://ceiba.agro.uba.ar/cgi-bin/koha/opac-detail.pl?biblionumber=45747 http://ceiba.agro.uba.ar/cgi-bin/koha/opac-detail.pl?biblionumber= http://ceiba.agro.uba.ar/cgi-bin/koha/opac-detail.pl?biblionumber= |
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