title: Early vigour improves phosphate uptake in wheat.
abstract: Quantitative trait loci (QTLs) for shoot biomass were identified in wheat grown on a soil high in total phosphorus (P) but low in plant-available P. The two populations screened included recombinant inbred lines (RILs) from Chuan-Mai 18/Vigour 18 and doubled-haploid lines from Kukri/Janz. Glasshouse-grown plants were harvested at the five-leaf stage. Seven QTLs for shoot biomass were identified in the RILs, with the largest on chromosome 7A accounting for 7.4% of the phenotypic variance. RILs from the upper tail had larger embryos than RILs from the lower tail. Tail lines were then grown in non-limiting P and the results indicated that early vigour and the capacity to access P contributed to the initial distribution. The influence of early vigour on P nutrition was examined further with advanced vigour lines (AVLs). The AVLs accumulated more shoot biomass, maintained lower shoot P concentrations, and showed greater P-acquisition efficiency than Vigour 18. Nine QTLs for shoot biomass were identified in the Kukri/Janz population. Two on chromosomes 4B and 4D accounted for 24.8% of the variance. Candidates underlying these QTLs are the Rht genes. We confirmed the influence of these genes using near-isogenic lines with different Rht alleles. The dwarf and semi-dwarf alleles affected shoot and root biomass at high and low P but not the efficiency of P acquisition. We conclude that early vigour contributed to the distributions in both populations. Early vigour can increase plant growth at suboptimal P and some sources can also improve the efficiency of P acquisition.
authors: CSIRO Agriculture, GPO Box 1600, Canberra ACT 2601, Australia Peter.Ryan@csiro.au.
authors: Peter R
authors: PR
authors: Ryan
authors: CSIRO Agriculture, GPO Box 1600, Canberra ACT 2601, Australia.
authors: Mingtan
authors: M
authors: Liao
authors: CSIRO Agriculture, GPO Box 1600, Canberra ACT 2601, Australia.
authors: Emmanuel
authors: E
authors: Delhaize
authors: CSIRO Agriculture, GPO Box 1600, Canberra ACT 2601, Australia.
authors: Gregory J
authors: GJ
authors: Rebetzke
authors: CSIRO Agriculture, GPO Box 1600, Canberra ACT 2601, Australia.
authors: Chandrakumara
authors: C
authors: Weligama
authors: CSIRO Agriculture, GPO Box 1600, Canberra ACT 2601, Australia.
authors: Wolfgang
authors: W
authors: Spielmeyer
authors: CSIRO Agriculture, GPO Box 1600, Canberra ACT 2601, Australia.
authors: Richard A
authors: RA
authors: James
mesh_terms: D018533:Biomass; D003433:Crosses, Genetic; D010710:Phosphates / Q000378:metabolism*; D040641:Quantitative Trait Loci; D014908:Triticum / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*
chemical_list: D010710:Phosphates
keywords: Early vigour; QTL; Rht genes; phosphate uptake; phosphorus; wheat.