Mapping candidate QTLs related to plant persistency in red clover

Abstract

Red clover (Trifolium pratense L.) is a diploid (2n = 14), self-incompatible legume that is widely cultivated as a forage legume in cold geographical regions. Because it is a short-lived perennial species, improvement of plant persistency is the most important objective for red clover breeding. To develop a marker-assisted selection (MAS) approach for red clover, we identified candidate QTLs related to plant persistency. Two full-sib mapping populations, 272 × WF1680 and HR × R130, were used for QTL identification. Resistance to Sclerotinia trifoliorum and Fusarium species, as well as to winter hardiness, was investigated in the laboratory and in field experiments in Moscow region (Russia), and Sapporo (Japan). With the genotype data derived from microsatellite and other DNA markers, candidate QTLs were identified by simple interval mapping (SIM), Kruskal–Wallis analysis (KW analysis) and genotype matrix mapping (GMM). A total of 10 and 23 candidate QTL regions for plant persistency were identified in the 272 × WF1680 and the HR × R130 mapping populations, respectively. The QTLs identified by multiple mapping approaches were mapped on linkage group (LG) 3 and LG6. The significant QTL interactions identified by GMM explained the higher phenotypic variation than single effect QTLs. Identification of haplotypes having positive effect QTLs in each parent were first demonstrated in this study for pseudo-testcross mapping populations in plant species using experimental data.Electronic supplementary materialThe online version of this article (doi:10.1007/s00122-009-1253-5) contains supplementary material, which is available to authorized users.

Achievements and Challenges in Improving Temperate Perennial Forage Legumes

“…Genetic analyses including QTL discovery have contributed to understanding of the trait, with QTL for stem length, seed yield and persistence all co-located (Herrmann et al, 2008). An independent study identified QTL for plant persistence on groups 3 and 6 (Klimenko et al, 2010). Narrowsense heritability estimates for forage yield traits ranged from moderate to low (Taylor and Smith, 1979).…”

“…Cold tolerance contributes to red clover yield and persistence in northern latitudes (Klimenko et al, 2010;Ravagnani et al, 2012), but its basis and genetic variation have been less investigated than in alfalfa and white clover. Red clover is not considered reliably persistent in cold-winter conditions.…”

Modern methods for genetic improvement of Trifolium pratense.

“…Klimenko et al (2010) developed a marker-assisted selection approach for red clover to identify candidate QTLs related to plant persistency. This is a complex trait and its investigation was associated with resistance to biotic stress caused by the most frequent pathogens Sclerotinia trifoliorum and Fusarium species (F. oxysporum, F. solani, and F. roseum), as well as to abiotic stress connected with low temperature (winter hardiness).…”

Development of Genomic Resources in the Species of Trifolium L. and Its Application in Forage Legume Breeding

“…Herrmann et al [43] used vigour scores after three growing seasons to identify QTL for persistence on LG3. Klimenko et al [44] used two of the mapping families described above [42] to identify QTL for winter hardiness, resistance to S. trifoliorum and the root rot fungus Fusarium, and found consistent QTL on linkage groups 1, 3 and 6. Given the complex nature of these traits, it is not surprising that the heritabilities they reported were quite low.…”

“…Given the complex nature of these traits, it is not surprising that the heritabilities they reported were quite low. It was also noticeable that a range of interacting QTLs were identified, highlighting the fact that pyramiding single effect QTLs may not bring sufficient improvement to breeding populations, but that it is important to ensure that all the interacting QTLs are present in the elite germplasm [44].…”