Septoria and Stagonospora Diseases of Cereals - CIMMYT ...

The seedlings were inoculated
when the second leaves were fully
expanded with a 1 x 10 6 spore/ml
suspension of an aggressive isolate
(S353/88). The plantlets were then
placed in propagators and
transferred to growth chambers for
72 h at 15 o C in complete darkness
to establish infection. Once this had
been completed, the plants were
moved to a containment glasshouse
and removed from their
propagators. Disease was scored at
10 and 17 days post-inoculation
and expressed as the percentage of
leaf area lesioned (at the intervals 1,
5, 10, 25, 40, 60, 75, 90, and 100%).
The scores were transformed using
the angular transformation and an
analysis of variance carried out
using the GENSTAT 5 statistical
package. The significance of
Chinese Spring ditelocentric for the long arm
(2n = 42 tt)
Background
Chinese Spring monosomic (2n = 41)
Selfing of each monosomic plant
Using Precise Genetic Stocks to Investigate the Control of Stagonospora nodorum Resistance in Wheat 151
differences in the mean scores
relative to ‘Chinese Spring’ and
‘Synthetic 6x’ was estimated using
a two-tailed t-test.
Morphological characters were
scored on field plots, with three
replicates of 11 plants in
randomized blocks to enable QTL
analysis and screening for Vrn3.
Biochemical analysis involved
the isoelectric focusing technique,
using seed embryo or endosperm
on flat bed electrophoresis
apparatus, showing separation of
the proteins at their relevant
isoelectric points (pI) (Liu and
Gale, 1989).
X
X
Cs/Syn 5D (2n = 42)
Selection of monosomic plants (2n = 41 ) or monotelosomics (2n = 41 t)
Selection of disomic (2n = 42) single chromosome recombinant lines (SCRs)
Figure 1. Development of single chromosome recombinant lines (SCRs) for the long arm of chromosome
5D (18).
F1
Molecular marker techniques
required extraction of DNA (phenol
chloroform method) and in the case
of RFLPs digesting with enzymes
that have a 4 base-pair recognition
sequence (Bam HI, Eco RI) and
then hybridizing with P 32 labeled
CTP (Southern, 1975). The microsatellite
technique was PCR-based
and used micro-satellite probes
developed at IPK-Gatersleben. Both
techniques clearly revealed the SCR
progeny as either ‘Chinese Spring’
or ‘Synthetic 6x’ type.
Marker results were input into
Mapmaker (Lincoln et al., 1992) to
compare the segregation of
markers in the progeny, and a map
of resistance gene(s) location
5D