State of QTL Detection and Marker-Assisted Selection in Wheat Improvement - Wheat Science and Trade - page 305

Table 14.4 Examples of DNA markers for major genes controlling important agronomic, disease, and cereal quality traits in

wheat.

Marker

Trait Gene Type a Reference

Agronomic traits
Growth habit

VRN-A1 CAPS Sherman et al. (2004)

Preharvest sprouting Vp-1B STS Yang et al. (2007)

Plant height Rht-B1b, -D1b STS Ellis et al. (2002)

Plant height Rht8 SSR Korzun et al. (1998)

Aluminum tolerance Alt-BH RFLP Riede and Anderson (1996)

Boron tolerance — RFLP Jefferies et al. (2000)

Pest resistance
Common bunt Bt10 STS Laroche et al. (2000)

Cereal cyst nematode Cre1 , Cre3 STS Ogbonnaya et al. (2001a,b)

Hessian fl y H6 STS Dwiekat et al. (2002)

Hessian fl y H9 SCAR Kong et al. (2005)

Leaf rust Lr28 STS Naik et al. (1998)

Durable leaf rust Lr34 STS Spielmeyer et al. (2005)

Loose smut — SCAR Knox et al. (2002)

Powdery mildew Pm24 AFLP Huang et al. (2000)

Stem rust Sr39 SCAR Gold et al. (1999)

Stripe rust Yr26 STS Wang et al. (2008)

Wheat midge Sm1 SCAR Thomas et al. (2005)

Wheat streak mosaic virus Wsm1 STS Talbert et al. (1996)

Cereal quality
Flour color

— STS Parker and Langridge (2000)

High protein content Gpc-B1 STS Distelfeld et al. (2006)

Storage proteins Glu-A1,B1,D1 STS Radovanovic and Cloutier (2003)

Polyphenol oxidase — STS He et al. (2007)

Yellow pigment color Psy-A1 STS He et al. (2008)

a CAPS, cleavage amplifi cation polymorphic sequence; STS, sequence tagged site; RFLP, restriction fragment length
polymorphism; SSR, simple sequence repeat (microsatellites); SCAR, sequence characterized amplifi ed region; AFLP,
amplifi ed fragment length polymorphism.

Another utility of whole-genome genotyping is
construction of chromosome-substitution lines or
advanced-backcross substitution lines containing
single chromosome segments introgressed into a
common genetic background. This process was
well described by Huang et al. (2004) and can
be useful for validation and characterization of
QTLs.

wheat breeder will insist on to commit to using
MAS for a trait. Similar to breeding practices, it
is more useful and relevant to test and measure
traits in multiple environments rather than repli-
cate extensively within few environments. Exam-
ples of highly replicated QTL analysis include
testing for grain yield (Kuchel et al., 2007b,c).
These experiments included 18 environments
and could test for the persistence of QTLs over
environments.
Ultimately, wheat breeders can consider this
information and determine how robust a particu-
lar QTL is and whether it is worth committing
resources toward MAS and reliance on the geno-
typing data for selection. In some cases, such as
yield or a complex disease reaction such as FHB
resistance, breeders are more likely to rely on well

Replicated fi eld analysis
The importance of replicated fi eld trials in many
environments for QTL analysis cannot be under-
estimated. One of the most useful predictors of
effective, robust QTLs is the detection of a QTL
within a defi ned chromosome interval in multiple
environments. This is the essential evidence a