Cucurbit Genetics Cooperative Report 10:51-55 (article 29) 1987
M. Pitrat, C. Ferrière, M. Ricard
Institut National de la Recherche Agronomique 84140 Avignon-Montfavet, France
Until now 9 independent gene groups have been described in muskmelon. We continue to make systematic studies to improve our knowledge of melon genetics. The names and symbols of the genes used in this paper are these of the reference list (1).
Virescent (v) has previously been found independent from genes belonging to groups 1,2,3,4,6,7,8,9 (3). In a F2 progeny with a line with Papaya ringspot virus resistance (Prv in group 5) we found 137 Resistant/47 Susceptible (X2 = .15084; Prob = 69.8 %) among the v+/- plants (v/v are more or less lethal). We conclude that v is not in group 5 and is alone in group 10.
Linkage of Pm-3 (Powdery mildew resistance in PI 124111 or VA 435) with short internode-1 (si-1 in group 1), necrotic spot virus resistance (nsv in group 7), cut leaf (cl in group 9) and long mainstem internode (lmi) has been tested (Table 1). We found it independent from si-1, cl and lmi but linked with nsv (distance = 33.9 according to the maximum likelihood method).
A gene controlling powdery mildew resistance in WMR 29 (2) provisionally named Pm-w and which is different from Pm-3 (about 1/16 susceptible in F2) has been found linked with Virus aphid transmission resistance (Vat) and Flaccida necrosis (Fn) in group 2 (Table 2). We have tested the back crosses with the double recessives. In (Vat Pm-w + /Vat+ Pm-w) x (Vat + Pm-w+) progeny we found 4 [Vat Pm-w] : 114 [Vat+ Pm-w] : 106 [Vat Pm-w+]: 5 [Vat+ Pm-w+] X2 = 194.98 percentage of recombination = 3.9. In (Fn Pm-w+/ Fn+ Pm-w) x (Fn+ Pm-w+) progeny we found 0 [Fn Pm-w] : 96 [Fn Pm-w +] : 93 [Fn+ Pm-w] : 3 [Fn + Pm-w+] X2 = 180.37 percentage of recombination = 1.6. As the distance between Fn and Vat has been estimated to 11.6 we can conclude that Pm-w is between Fn and Vat.
Long mainstem internode (lmi) has been found independent from genes belonging to groups 2,3,4,5,6,7 and 9 (Table 3) and flava (f) from groups 3,8 and 10 but linked with lmi (Table 4). The group f-lmi must still be tested with group 1. Male sterile -3 (ms-3) is independent from groups 2,3,4,6,10 and also from f- lmi (Table 5).
In conclusion the linkage groups in muskmelon may be summarized as follows:
- group 1 : si-1 yv
- group 2 : Vat Pm-w Fn
- group 3 : ms-1 r gl Pa
- group 4 : Zym a h Pm-X (order unknown)
- group 5 : Prv Fom-1
- group 6 : ms-2 yg Fom-2
- group 7 : nsv Pm-3
- group 8 : ms-4
- group 9 : cl
- group 10 : v
- group 11 : f Imi (independent from groups 2 to 10 but must be tested with group 1)
Table 1 : Segregation data observed in F2 progenies between powdery mildew resistance (Pm- 3) and si-1, nsv, cl, and lmi
z C : Coupling R : Repulsion
Table 2 : Segregation data observed in F2 progenies between powdery mildew resistance of WMR 29 (Pm-w) and Vat, Fn, Fom-1, Pw and Fom-2
z C : Coupling R : Repulsion
Table 3 : Segregation data observed in F2 progenies between long mainstem internode (lmi) and Vat, gl, Zym, Fom-1, Fom-2, yg, nsv, Pm-3 and cl (all in repulsion phase)
Table 4 : Segregation data observed in F2 progenies between flava (f) and gl, ms- 4, v and lmi (all in repulsion phase)
Table 5 : Segregation data observed in F2 progenies between male sterile-3 (ms-3) and Vat, gl, Zym, yg, v, and f (all in repulsion phase) CGC 10:55 (1987)
Literature Cited
- Cucurbit Genetics Cooperative. 1986. Gene List for Muskmelon (Cucumis melo L.). Cucurbit Genetics Coop. Rept. 9 : 111-120.
- McCreight J.D., M. Pitrat, C.E. Thomas, A.N. Kishaba, G.W. Bohn. 1986. Powdery mildew resistance genes in muskmelon. J. Amer. Soc. Hort. Sci. 112 : (in press).
- Pitrat M., C. Ferriere, M. Ricard. 1986. Attempt at localization of male sterile-4, cut leaf and virescent mutants in muskmelon. Cucurbit Genetics Coop. Rept. 9 : 64-6.