PISUM GENETICS
2011-VOLUME 43
RESEARCH PAPERS
A new chlorophyll gene (xach, xantha chlorescens) in Pisum
sativum L. located on LG II
Swiecicki, W.K., Institute of Plant Genetics, Polish Academy of Sciences, Poznaii, Poland
Gawlowska, M.
and Nawrot, cz.
Induced mutations substantially increase the range of genetic variation in Pisum (eg. new genes orp, art, nec, lum etc.).Numerous accessions maintained in the Polish Pisum Gene Bank are mutations induced at the
Plant Experiment Station at Wiatrowo (1, 2). Some of these, such as the one discussed in this paper, were
obtained after treatment of both physical and chemical mutagens.
Dry seeds of cv. Paloma (Wt 3527) were treated with 200 rNf +0.014% NEU, and a chlorophyll mutant
from the terminalis group was selected in the M2 generation. During germination and initial growth (up
to 4-5 leaves) mutant plants are gold-yellow-green (Figure 1A) and could be used as an ornamental pea.
After this initial growth the plant becomes green and is fertile (Figure 1B). The phenotype is clearly
different from other described chlorophyll mutations of this group. The mutant has been included in the
Polish pea collection under the name xantha-chlorescens (accession number Wt 10889).
Figure 1. Mutantplants of cultivar Paloma snowing chlorosis during early vegetative growth (A) and recovery of normal green folage color (BB).
This line was crossed to following testerlines with gene markers: Wt 11540 - A, wb, Pgm-p (LG II); gp, tl,
Acpl (LG V); Aat-m, Skdh, Estl, Est-2 (LG VII); Wt 11288 - A (LG II); st, b, (LGIII) and Wt 15860 - A (LG II);
creep, ce (LG V). Segregation of the mutation in the F2 in 1999 showed no deviations from an expected
monohybrid segregation (Table 1). The gene symbol, xach, is suggested for the xantha-chlorescens mutation
in the type line Wt 10889.
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Table 1. Monohybrid segregation for the investigated gene xach (xanta-chlorescens) and gene markers in the linkagegroup II
in F2 populations of the linkage test crosses._
Cross no.
Parents
Gene
Dom
Rec
Total
chi2
K. 2022
Wt 11540 x Wt 10889
Xach
70
25
95
0.09
A
74
17
91
1.94
K. 2024
Wt 11288 x Wt 10889
Xach
72
22
94
0.13
A
72
10
82
7.17
K. 2026
Wt 10889 x Wt 15860
Xach
69
25
94
0.13
A
62
11
73
3.84
K. 2718
Wt 10886 x Wt 16054
Xach
97
29
126
0.26
Rms3
79
20
99
1.22
K. 2795
Wt 10886 x Wt 15869
Xach
108
38
146
0.08
A
88
41
129
3.16
Pal
118
20
138
8.13
K. 2894
Wt 10886 x Wt 11300
Xach
89
30
119
0.00
A
89
30
119
0.00
Crd
95
24
119
1.48
K. 3012
Wt 3838 x Wt 10888
Xach
174
55
229
0.12
A
161
60
221
0.54
161
55
216
0.02
Analyses of the dihybrid segregation in the three mapping populations showed independent assortment
between xach and all genes listed in Table 2. In contrast, substantial deviations were observed for Xach-A
with the joint chi square from 21.4 to 50.8 and Cr-O values 8.27 in K.2022, 12.3 in K.2024 and 15.5 in
K.2026. This suggests localization of xach on LG II (3).
Table 2. Distribution of phenotypes in F2 populations (Wt10889xach type line x testerlines) and the linkage testfor the new gene.
Testerline (Cross
no.)
Pair of genes
DD
Dr
rD
rr
Total
Joint chi
square
Cr-o (±S.E) (per
cent)
Phase
Wt 11 540 (K.
2022)
Xach-Gp
53
16
14
4
87
0.01
49.2
8.11
R
Xach-Tl
52
18
17
2
89
1.98
35.1
9.16
R
Xach-Wb
54
15
15
3
87
0.22
45.4
8.44
R
Xach-Ac
57
9
16
5
84
0.08
46.7
8.48
R
Xach-Aat-m
32
7
9
2
50
0.00
50.2
10.6
R
Xach-Skdh
28
10
9
2
49
0.30
43.3
11.5
R
Xach-Acpl
27
11
10
1
49
1.82
69.1
12.8
C
Xach-Pgm-c
32
7
10
1
50
0.50
39.1
11.8
R
Xach- Pgm-p
25
11
9
1
46
1.72
68.7
13.2
C
Xach-Est-1
30
9
9
2
50
0.12
45.8
11.1
R
Xach- Est-2
28
11
9
2
50
0.45
58.0
11.5
C
Wt 11 288
(K.2024)
Xach-St
56
16
10
5
87
0.84
57.7
7.32
R
Xach-B
51
17
2
2
72
1.22
64.7
7.29
R
Wt 15 860
(K.2026)
Xach-Creep
51
17
11
6
85
0.73
56.8
7.50
R
Xach-Ce
38
15
1
2
56
1.98
70.9
7.45
R
K.2024 and K.2026 single plants were selected from F2 segregating populations and lines were multiplied
with linked genes xach-A in repulsion phase (Wt 10888 and Wt 10886, respectively). These lines were
crossed to additional LG II marker lines: Wt 16054 (rms3), Wt 15869 (pal), Wt 11300 (crd) and Wt 3838
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(lf) (Table 1.). Analysis of the dihybrid segregation in the F2 confirmed that xach is linked with A,
although Cr-O values in repulsion were larger (from 19.6 to 29.3) than in coupling (Table 3). No linkages
of xach with markers rms3, pal and crd were observed. However, in the population K.3012 substantial
deviations from the expected dihybrid segregation were stated for three gene pairs: Xach-A, Xach-Lf and
A-Lf. Cr-O values suggest the following gene order: Xach-14-Lf-19-A.
Table 3. Distribution of phenotypes in F2 populations (xach lines x testerlines) and the linkage test for the new gene.
Cross no.
Pair of genes
DD
Dr
rD
rr
Total
Joint chi
square
Cr-O (±S.E)
(per cent)
Phase
K. 2022
Xach-A
68
2
5
14
89
50.8
8.27
3.07
C
K.2024
Xach-A
68
3
4
7
82
31.4
12.3
3.92
C
K.2026
Xach-A
59
5
3
6
73
21.4
15.5
4.68
C
K.2718
Xach-Rms-3
73
20
6
1
99
1.27
43.0
8.10
R
K.2795
Xach-A
68
40
20
1
129
9.26
19.6
8.40
R
Xach-Pal
89
19
29
1
138
3.26
26.0
7.84
R
A-Pd
74
13
35
6
128
00.0
50.3
6.65
C
K.2894
Xach-A
61
28
28
2
119
8.31
25.6
8.47
R
Xach- Crd
69
20
26
4
119
1.11
41.1
7.52
R
A-Crd
83
6
12
18
119
40.0
16.4
3.78
C
K.3012
Xach-A
113
55
48
5
221
10.3
29.3
6.07
R
Xach-Lf
111
54
50
1
216
19.5
14.0
6.64
R
A-Lf
138
16
22
38
214
65.2
18.9
3.03
C
References
1. Swiecicki W.K. 1984. Pisum Newslet. 16: 84-86.
2. Swiecicki W.K. 1998. Crop Gene Resources. Nation. Conf. Pulawy: 53-54.
3. Weeden N.F., T.H.N. Ellis, G.M. Timmerman-Vaughan , W.K. Swiecicki, S.M. Rozov and V.A.
Berdnikov. 1998. Pisum Genetics 30: 1-4.
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