Changes in durum wheat root and aerial biomass caused by the introduction of the Rht-B1b dwarfing allele and their effects on yield formation uri icon

abstract

  • A historical series of 24 Mediterranean cultivars with allelic variants a (tall) and b (semi-dwarf) at Rht-B1 locus was tested in tubes in three greenhouse experiments and six field experiments.
  • The dwarfing allele reduced the aerial biomass of each plant at anthesis by 7.6 % and the root by 28.1 % (25.4 %, 26.7 % and 36.0 % in the upper, middle and lower root sections, respectively). Aerial and root biomass were reduced by 27.0 g y(-1) and 7 g y(-1) respectively, but the relative rate of change was much greater for roots (-0.73 % y(-1)) than for aerial organs (-0.17 % y(-1)). Aerial biomass at anthesis was negatively associated with spike number, harvest index and yield in tall cultivars, but no significant relationship was found for semi-dwarf ones.
  • The root/aerial biomass ratio was 29 % lower in semi-dwarf than in tall cultivars. In tall cultivars large aerial biomass at anthesis was detrimental to yield formation, while in semi-dwarf cultivars high aerial biomass at anthesis had no effect on yield formation.
  • This study aimed to quantify the changes in root and aerial biomass of durum wheat brought about by the introduction of the Rht-B1b dwarfing allele and their effects on yield formation.

publication date

  • 2016
  • 2016