caa a22 4500 477134610 CHVBK 20180405111714.0 cr unu---uuuuu 170330e19971001xx s 000 0 eng 10.1023/A:1003061706059 doi (NATIONALLICENCE)springer-10.1023/A:1003061706059 Radiation interception and radiation use efficiency of near-isogenic wheat lines with different height [Elektronische Daten] [Daniel Miralles, Gustavo Slafer] Three near isogenic lines of spring wheat grown to determine whether Rht dwarfing alleles alter radiation interception. A field study (involving two sowing dates in two growing seasons) with lines containing different allelic dosage of Rht1 and Rht2 (i.e. dwarf, DD; semi-dwarf, SD and tall SH), was conducted without water and nutritional deficiencies. Dwarfing genes did not modify the timing of occurrence of phenological events. Above-ground biomass at anthesis was reduced by 22% in the DD line in relation of the rest of the lines. However, at maturity accumulated biomass of the DD and SH lines were not significant different. Dwarfing genes increased the light attenuation coefficient (k, with values of 0.48, 0.62 and 0.78 for the SH, SD and the DD line respectively). A similar trend was followed to the leaf thickness (estimated by the specific leaf weight, SLW). Despite the differences observed among the lines, both in k and SLW values, they did not differ significantly in the proportion of incoming radiation intercepted by the canopy, nor in the cumulative intercepted radiation during the pre and post-anthesis periods. Radiation use efficiency (RUE) differed significantly among the lines. While RUE during pre-anthesis was the lowest in the DD line, from anthesis to maturity the lines with Rht alleles showed higher RUE values than the SH line. The low pre-anthesis RUE in the DD lines could be associated with (i) poor canopy architecture due to reductions in leaf sheath and internode lengths and/or (ii) reduced canopy CO2 exchange rate. Post-anthesis RUE was lower than that recorded pre-anthesis in all lines. But the magnitude of the reduction was inversely related to the doses of the Rht alleles. Post-anthesis RUE appeared to be closely and positively associated with the number of grains set per unit biomass at anthesis. This relationship suggests a regulatory effect of the sink size on the efficiency of the crop to convert radiation into biomass during this period. Kluwer Academic Publishers, 1997 dwarfing genes nationallicence wheat nationallicence radiation interception nationallicence radiation use efficiency nationallicence Miralles Daniel Catedra de Cerealicultura, Departamento de Produccion Vegetal, Facultad de Agronomia, Universidad de Buenos Aires, Av. San Martin 4453, 1417, Buenos Aires, Argentina aut Slafer Gustavo Catedra de Cerealicultura, Departamento de Produccion Vegetal, Facultad de Agronomia, Universidad de Buenos Aires, Av. San Martin 4453, 1417, Buenos Aires, Argentina aut Euphytica Kluwer Academic Publishers 97/2(1997-10-01), 201-208 0014-2336 97:2<201 1997 97 10681 https://doi.org/10.1023/A:1003061706059 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1023/A:1003061706059 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Miralles Daniel Catedra de Cerealicultura, Departamento de Produccion Vegetal, Facultad de Agronomia, Universidad de Buenos Aires, Av. San Martin 4453, 1417, Buenos Aires, Argentina aut NATIONALLICENCE 700 1- Slafer Gustavo Catedra de Cerealicultura, Departamento de Produccion Vegetal, Facultad de Agronomia, Universidad de Buenos Aires, Av. San Martin 4453, 1417, Buenos Aires, Argentina aut NATIONALLICENCE 773 0- Euphytica Kluwer Academic Publishers 97/2(1997-10-01), 201-208 0014-2336 97:2<201 1997 97 10681 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer