Relationships between physiological traits, grain number and yield potential in a wheat DH population of large spike phenotype uri icon

abstract

  • Our objective was to investigate the relationships between spike traits, grain number and yield potential and their physiological basis in a doubled-haploid (DH) population derived from a cross between a CIMMYT spring wheat (Triticum aestivum L.) advanced line of large-spike phenotype (LSP2; +Tin1 tiller inhibition gene) and the UK winter wheat cultivar Rialto (R; -Tin1) of conventional spike phenotype. Field experiments were carried out in high radiation, irrigated conditions in NW Mexico in two seasons. Comparing the two groups of +Tin1 and -Tin1 DH lines, results showed the presence of the +Tin1 gene for tiller inhibition increased spike partitioning index (spike DM/above-ground DM at GS61 + 5 d; SPI) from 0.32 to 034 (+6.3%) (P <0.01) and grains spike(-1) by 5.1 (+13.9%) (P <0.001), but reduced spikes m(-2) by 20.7 (-5.7%) (P <0.01). Overall a significant increase in grains m(-2) of 865 (+6.6%) was observed in +Tin1 DH lines compared to -Tin1 DH lines (P< 0.05), but the effect on grain yield was not statistically significant. Above-grouund biomass at anthesis was not significantly affected by the presence/absence of the Tin1 gene; although results indicated the presence of the Tin1 gene increased photosynthetically active radiation interception from onset of stem elongation to anthesis, but decreased radiation-use efficiency during this phase. Our results indicated that introgressing the +Tin1 gene into modern wheat germplasm may offer scope to increase grains spike(-1) and grains m(-2) in irrigated, high radiation environments. (C) 2014 Elsevier B.V. All rights reserved.

publication date

  • 2014
  • 2014