Transcript Poster. - University of Warwick

Characterisation of post harvest shelf life in broccoli.
Emma Skipper, Vicky Buchanan-Wollaston and David Pink.
Warwick HRI, University of Warwick, Wellesbourne, Warwick, CV35 9EF, UK.
Introduction:
Mar34
GD33
Broccoli (Brassica oleracea var italica) is a popular green vegetable
consumed as a part of a healthy diet. Broccoli has a high vitamin and
mineral content and contains health promoting properties such as
antioxidants, flavonoids and glucosinolates. However broccoli has a
notorious short shelf life displaying rapid senescence after harvest.
Characteristics of a poor quality broccoli include a yellow appearance
due to chlorophyll degradation, loss of flavour, reduced nutritional content
and wilting as a result of a turgor loss, causing a high level of waste for
retailers and consumers. The overall aim of this project is to investigate
the effects of genetics on the gene expression and metabolite content of
broccoli florets, to improve the shelf life of broccoli.
X
Previous studies using double haploid (DH) lines as a mapping
population to measure yellowing using colour charts and chromameter
readings has located 9 QTLs relating to bud yellowing.
Mar34 x GD33 F1 used to generate a doubled haploid mapping population
Days to yellowing of the GD33 x MAR34 lines.
Project Aims:
•To improve the existing linkage map for the trait bud yellowing
by incorporating more markers onto the linkage map.
Distribution of yellowing of DH lines
5.00
Mar34
•To identify one major QTL accounting for the majority of the
variation in shelf life seen within the population for more
detailed molecular analysis.
4.50
F1
Days to Yellowing
4.00
3.50
GD33
3.00
2.50
•To investigate the effects of the presence of the QTL on
metabolite content. To link metabolite content with shelf life.
2.00
1.50
1.00
•To investigate gene expression patterns during senescence to
identify genes controlled by the selected QTL.
M G 138 27/9
M G 982 7/9
M G 132 27/9
M G 44
M G 19
M G 107 B
M G 100
M G 184 B
M G 99
M G 18
M G UNID1
M G 89
M AR34
M G 63
M G 346
M G 952 7/9
M G 13
M G 183 B
M G 187 B
M G 327
M G 308
M G 182 0
M G 48
M G 181 2
M G 57
M G 285
M G 188 B
M G 310
M G 306
M G 182 9
M G 142 7/9
M G 116
M G 334
M G 110
M G 100 27/9
M G 182 4
M G UNID2
M G 182 2
M G 120 27/9
M G 927 /9
M G 10
M G 124 27/9
M G 181 4
M G 227 /9
M G 127 27/9
F1
M G 181 0B
M G 330
M G 118 27/9
M G 181 3
M G 350
M G 892 7/9
M G 182 5
M G 185 B
M G 392 7/9
M G 333
M G 136 27/9
G D33
M G 412 7/9
M G 126 27/9
M G 364
0.00
M G 181 0B
0.50
DH Line
Days to yellowing of GD33, MAR34, the F1 and 59 DH lines as assessed using the R.H.S colour
charts. The values are means of 6 heads per line per replicate per year.
LG 1
0
2
Current work:
The DH population is being screened with 60 SSRs (short
sequence of nucleotides, typically 2 to 5, that are repeated in
tandem), know to be polymorphic between the parents of the
cross, using PCR. The products of which are multiplexed using the
sequencer facilities. The trace data from the sequencer is inputted
into Genemarker software to look for polymorphisms between the
parental lines for each marker. Peak height data and genotype
data matrices are created from gene marker to be used in Joinmap
to create a linkage map based on LOD ratios. Using phenotypic
data and information from the linkage maps QTL analysis is
performed to locate QTLs for the trait bud yellowing.
LG 2
AC-CTAM5
AC-CTAM10
0
AA-CATG4
LG 4
0
LG 5
AC-CTAM1
BY4
aCC4
12 AC-CATG6
12 AC-CACM9
17
Ol10_D08
20 AC-CACG13
AC-CACM8
22 AC-CTCM3
AC-CAGM2
23
AC-CTCM6
25 AC-CATG2
27 AC-CACM2
35 AA-CATM6
BY1
HCC4, aCHR3
HCHR3
BY2
aCC4
24 AA-CATM5
27 AC-CAAM4
36 Na12_H09
35 AC-CAGG4
36 AC-CAGM4
46 BN83B1
51 AA-CTAM7
52 AC-CTAG7
54 AC-CTAG3
BY3
LCHR3, bCHR3
63
HCC3, CCHR3, HCC4, aCC4,
LG 7
LG 8
LG 9
AC-CTAM6
0
8
LG6
AC-CACG7
14
18
21
22
23
BY5
aCC3
24
29
32
BY6
LCC3, LCHR3
bCC3, bCHR3
HCC3, HCC4,
CCC3, CCHR3
aCC4,
BY7
CCC4
AC-CATM3
0
AC-CTAM11
3
5
8
MB4
AC-CATG5
AC-CAGG2
0
Ol12_G04
8 AC-CACM6
10 AC-CACM7
0
8
AA-CTAG4
0
AA-CATM7
4
AC-CTAG10
Na12_G12
12 AC-CTCG2
AC-CAGG3
AC-CAAG3
AC-CAAG4
AC-CATM5
AC-CTAM12
AA-CATG12
AA-CTAM8
AA-CATG18
Na12_C08
AC-CATG4
15 AA-CTAG5
18 AC-CTCG1
21 AC-CTCM1
39 AA-CATG8
BY8
LCHR3,
bCC3, bCHR3
HCC3, HCC4, CCHR3, aCC4
90 AA-CTAM2
48 AA-CTAG2
50 AA-CTAM5
66 AA-CTAM6
BY9
LCHR4
A linkage map of B. oleracea var italica based on the MAR34xGD33 DH population with
potential QTLs mapped relating to bud yellowing.
Future work:
•Analysis of key metabolites such as vitamin C, anthocyanins,
glucoraphanin and glucobrassicin using high liquid
performance chromatography (HPLC).
•Gene expression studies during senescence using
microarrays. Potential to identify genes involved in
senescence by comparison with the model plant system
Arabidopsis
•Field trials in 2007 and 2008 to record phenotypic data to
improve QTL definition for traits such as yellowing, head
weight, diameter and circumference.