Does fructan have a functional role in physiological traits? Investigation by quantitative trait locus mapping.
* The role of fructan in growth and drought-stress responses of perennial ryegrass (Lolium perenne) was investigated in an F(2) mapping family that segregates for carbohydrate metabolism. * A quantitative trait locus approach was used to compare the genetic control of traits. * Growth and drought-stress traits were extremely variable within the family. Most traits had high broad-sense heritability. Quantitative trait loci (QTL) were identified for most traits; the maximum number of QTL per trait was four. Between 11% and 75% of total phenotypic variation was explained. Few growth-trait QTL coincided with previously identified fructan QTL. A cluster of drought-trait QTL was close to two previously identified regions of the genome with tiller base fructan QTL in repulsion. * The high sugar parent contributed few alleles that increased 'reserve-driven' growth or performance during drought-stress. Correlation of growth and drought-stress traits with fructan content was low and increasing fructan content per se would not appear to improve drought resistance. Complex patterns of carbohydrate partitioning and metabolism within the cell may explain contradictory relationships between carbohydrate content and growth/stress-resistance traits.
Institute of Grassland and Environmental Research (IGER) , Plas Gogerddan, Aberystwyth, Ceredigion, SY23 3EB. UK.
L B
LB
Turner
Institute of Grassland and Environmental Research (IGER) , Plas Gogerddan, Aberystwyth, Ceredigion, SY23 3EB. UK.
A J
AJ
Cairns
Institute of Grassland and Environmental Research (IGER) , Plas Gogerddan, Aberystwyth, Ceredigion, SY23 3EB. UK.
I P
IP
Armstead
Institute of Grassland and Environmental Research (IGER) , Plas Gogerddan, Aberystwyth, Ceredigion, SY23 3EB. UK.
H
H
Thomas
Institute of Grassland and Environmental Research (IGER) , Plas Gogerddan, Aberystwyth, Ceredigion, SY23 3EB. UK.
M W
MW
Humphreys
Institute of Grassland and Environmental Research (IGER) , Plas Gogerddan, Aberystwyth, Ceredigion, SY23 3EB. UK.
M O
MO
Humphreys
D002874:Chromosome Mapping; D032461:Chromosomes, Plant; D005630:Fructans / Q000378:metabolism*; D008040:Genetic Linkage; D018745:Genome, Plant; D008129:Lolium / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D010641:Phenotype; D040641:Quantitative Trait Loci; D014867:Water / Q000378:metabolism
D005630:Fructans; D014867:Water