Cucurbit Genetics Cooperative Report 7:51-53 (article
23) 1984
Linkage Studies in Muskmelon
Pitrat, M.
I.N.R.A., Centre de Recherches Agronomiques d'Avignon, B.P. 94,
84140 Montfavet, France
Until now only 4 gene linkages have been described in muskmelon:
(1) bush (b) and yellow virescent (yv) - recombination 19.4% (5); (2) virus aphid
transmission resistance (Vat) and Flaccida
necrosis (Fn) - recombination 11.6%; (3) red stem (r) and male sterile-1 (ms-1) -
recombination 25.6% (1); and (4) Zucchini yellow mosaic virus resistance (Zym) and andromonoecious (a) -
recombination 13.1% (3).
A program was begun to find linkage relationships between the
following genes:
- Fusarium oxysporum f. sp. melonis resistance: Fom-1 (resistance to pathotypes 0 and 2) in 'Doublon' and Fom-2 (resistance to pathotypes 0 and 1) in PI 414723
(supplied by G.W. Bohn).
- Watermelon mosaic virus-1 resistance (Wmv) in PI
414723.
- Necrotic spot virus resistance (nsv) to muskmelon
necrotic spot virus in VA 435 supplied by Virginia Truck Expt.
Sta.
- Zucchini yellow mosaic virus resistance (Zym) in PI
414723.
- Virus aphid transmission resistance (Vat) in PI
414723 or PI 161375.
- Powdery mildew resistance-X (Pm-X)
resistance to Sphaerotheca fuliginea race 2 in PI 414723
(exact powdery mildew resistance gene is under study).
- glabrous (gl) in Arizona gl B supplied by R.E. Foster.
- yellow green (yg) in Arizona gl B.
- red stem (r) in 30569 supplied by J. D. McCreight.
- bush (b) in 'Topmark Bush' supplied by F. W. Zink.
F2 data from 4 of 19 gene combinations among these 10 genes
studied to date strongly indicated linkage. The recombination
fractions for these 4 gene pairs were calculated using the
maximum likelihood method (Table 1). F2 data indicated
independent assortment between the other 15 gene pairs (Table 2).
Table 1. Linkage between 4 gene pairs in muskmelon.
|
Genes
| Phasez
| Number of plants observed in the
expected dihybrid ratio
| Chi square
| Recombination
|
9
| 3
| 3
| 1
| Value
| Standard error
|
Fom-1
| Wmv
| R
| 104
| 52
| 44
| 0
| 19.876
| 0.0
| 7.07
|
Fom-2
| yg
| R
| 161
| 10
| 17
| 53
| 145.309
| 11.4
| 6.34
|
Zym
| Pm-X
| C
| 110
| 47
| 40
| 0
| 15.314
| 0.0
| 7.12
|
r
| gl
| R
| 367
| 106
| 128
| 8
| 27.745
| 30.9
| 3.61
|
|
zC=coupling; R=repulsion. |
Table 2. Independent assortment between 15 gene pairs in
muskmelon.
|
Genes
| Phasez
| Number of plants observed in the
expected dihybrid ratio
| Chi square
|
9
| 3
| 3
| 1
|
Fom-1
| gl
| R
| 159
| 61
| 51
| 19
| 1.163
|
Wmv
| g
| R
| 113
| 31
| 36
| 13
| 0.999
|
Vat
| Zym
| C
| 107
| 36
| 29
| 17
| 3.461
|
Wmv
| nsv
| R
| 111
| 32
| 45
| 12
| 2.347
|
gl
| yg
| C
| 1177
| 394
| 377
| 141
| 1.402
|
yg
| b
| R
| 138
| 41
| 49
| 19
| 1.594
|
yg
| nsv
| R
| 167
| 62
| 56
| 19
| 0.550
|
Pm-X
| gl
| R
| 151
| 54
| 44
| 7
| 6.486
|
Zym
| nsv
| R
| 96
| 40
| 35
| 18
| 4.834
|
Vat
| b
| R
| 100
| 38
| 32
| 11
| 0.638
|
Vat
| nsv
| R
| 105
| 48
| 32
| 14
| 4.444
|
b
| gl
| R
| 141
| 47
| 46
| 13
| 0.428
|
b
| r
| R
| 108
| 31
| 31
| 9
| 1.350
|
gl
| nsv
| R
| 178
| 50
| 50
| 24
| 3.330
|
Zym
| b
| R
| 83
| 25
| 23
| 12
| 1.796
|
|
zC=coupling; R=repulsion. |
Vat was already found independent from Fom-1, Fom-2 and ms-1 (2), Zym independent from Fom-1 and Fom-2 (3) and Fom-l independent
from Fom-2 (4). The muskmelon linkage groups may
tentatively be summarized from these and published data:
- Linkage group 1 : b - yv
- Linkage group 2 : Vat - Fn
- Linkage group 3 : ms-1 - r - gl
- Linkage group 4 : Zym - a - Pm-X
- Linkage group 5 : Fom-l - Wmv
- Linkage group 6 : Fom-2 - yg.
Gene nsv is independent from linkage groups 2 to 6. Its
independence with group 1 is under study. The order in groups 3
and 4 is still unknown.
Literature Cited
- McCreight, J.D. 1983. Linkage of red stem and male sterile-1 in
muskmelon. Cucurbit Genetics Coop. Rept. 6:48.
- Pitrat, M. and H. Lecoq. 1982. Relations genetiques entre les
resistances par non-acceptation et par antibiose du melon a Aphis
gossypii. Recherches de liaisons avec d'autres genes. Agronomie
2:503-508.
- Pitrat, M. and H. Lecoq. 1984. Inheritance of zucchini yellow
mosaic virus resistance in Cucumis melo L. Euphytica 33 (in
press).
- Risser, G. 1973. Etude de l'heredite de la resistance du melon
(Cucumis melo) aux races 1 et 2 de Fusariuma oxysporum f. sp. melonis. Ann. Amelior. Plantes 23:259-263.
- Zink, F.W. 1977. Linkage of virescent foliage and plant growth
habit in muskmelon. J. Amer. Soc. Hort. Sci. 102:613-615.
