United Kingdom
October 20, 2008
Source:
Home-Grown
Cereals Authority (HGCA)
Crop Research News 56
PR441
Identification of genetic markers for lodging resistance in
wheat
P.M. Berry of ADAS High Mowthorpe, S.T. Berry of Nickerson
and J.H. Spink of ADAS Rosemaund.
HGCA Project No. 2976. Cost: £3.00
Wheat breeders have traditionally
increased lodging resistance by shortening crop height; however
the scope for further reducing crop height appears to be limited
because more extreme dwarfing genes have been shown to be
incompatible with high yields. Lodging either occurs through
buckling of the stem base (stem lodging) or through overturning
of the root anchorage system (root lodging). Lodging resistance
could therefore be increased by strengthening the stem base and
anchorage system. However these traits are not currently
assessed by breeders because they are too time consuming to
measure. This project therefore aimed to provide UK breeders
with new molecular tools to help them breed new wheat varieties
with greater lodging resistance by increasing stem and anchorage
strength.
Two breeding populations from Nickerson-Advanta were analysed
across three seasons. There was significant genetic variation
within plant breeder's germplasm for the traits which determine
stem strength and anchorage strength, and for height. Genetic
markers were found for several of the key traits that, with
further development and validation, could be used to facilitate
trait selection. Some of the genetic markers for increasing
lodging resistance were associated with lower yields. It was
shown that by selecting the correct combination of genetic
markers it would be possible to increase lodging resistance by
the equivalent of three varietal lodging resistance scores
(standing powers) without reducing yield. A different
combination of genetic markers would increase yield without
increasing lodging risk.
The project identified several height genes within UK elite
wheat varieties in addition to the 'standard' semi-dwarf genes.
If reliable genetic markers can be identified for these height
genes then plant breeders could select the most appropriate
parents for crossing in order to produce new varieties of
optimal height. The project also discovered that some height
genes are more responsive to plant growth regulators (PGRs) than
others which should pave the way for predicting varietal
responses to PGRs and so allowing them to be targeted more
accurately.
One of the genetic markers which identified a major yield gene
was shown to increase both grain and straw yields by about 0.5
t/ha each, and did not affect rooting at depth. This discovery
indicates that breeders can improve yield and stem strength
simultaneously. Straw is also an increasingly valuable
co-product for biomass and potentially for liquid biofuel
production. |
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