Identification of genetic factors influencing salt stress tolerance in white clover (Trifolium repens L.) by QTL analysis.
Allotetraploid (2n = 4x = 32) white clover (Trifolium repens L.) is the most commonly cultivated legume component of temperate pastures, sown in swards with a companion grass species. Genetic control of growth performance of white clover on saline land is highly important for dairy industries, due to increasing soil salinity problems. The objective of this study was to identify quantitative trait loci (QTLs) for salinity tolerance in terms of vegetative growth under stress. Two parental genetic maps consisting of 213 and 159 marker loci and spanning 1,973.0 and 1,837.6 cM, respectively, were constructed using simple sequence repeat (SSR) and single nucleotide polymorphism (SNP) markers from a two-way pseudo-test cross F(1) population derived from pair-crossing of the Haifa(2) and LCL(2) genotypes. A total of 8 unique genomic regions on 8 linkage groups (LGs) of the Haifa(2) parental map and 6 unique regions on 5 LGs in the LCL(2) parental map were associated with plant growth under salt stress and relative growth under stress, as compared to control conditions. The results of this study indicate that salt tolerance in white clover is controlled by multiple QTLs, some at common locations, but each of limited magnitude. Location of these QTLs provides the genetic basis and potential for pyramiding of salt tolerance genes in breeding improvement.
Biosciences Research Division, Department of Primary Industries, Hamilton Centre, Hamilton, VIC 3300, Australia.
Junping
J
Wang
Michelle C
MC
Drayton
Julie
J
George
Noel O I
NO
Cogan
Rebecca C
RC
Baillie
Melanie L
ML
Hand
Gavin A
GA
Kearney
Stacey
S
Erb
Tania
T
Wilkinson
Nathaniel R
NR
Bannan
John W
JW
Forster
Kevin F
KF
Smith
D018533:Biomass; D002874:Chromosome Mapping; D010641:Phenotype; D040641:Quantitative Trait Loci / Q000235:genetics*; D019655:Quantitative Trait, Heritable; D055049:Salt Tolerance / Q000187:drug effects / Q000235:genetics*; D012965:Sodium Chloride / Q000494:pharmacology; D013312:Stress, Physiological / Q000187:drug effects / Q000235:genetics*; D029921:Trifolium / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development
D012965:Sodium Chloride