Identification of the Gene for Resistance to Fusarium Wilt Races 0 and 2 in Cucumis melo ‘Dulce’

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Cucurbit Genetics Cooperative Report 22:19-20 (article 8) 1999

Y. Danin-Poleg, Y. Burger, S. Schreiber. N. Katzir and R. Cohen
Department of Vegetable Crops, Agricultural Research Organiation, Newe Ya’ar Research Center, P.O.B. 1021, Ramat Yishay 30095, Israel. E-mail: [email protected]

Four races of Fusarium oxysporum f.sp. melonis (0,1,2, and 1,2) cause wilt in melons. three independent dominant genes were reported to confer resistance to Fusarium wilt. Resistance is race specific. Two genes have been identified as conferring resistance to races 0 and 2, Fom-1 in ‘Doublon’ and ‘Hemed’ (Risser 1969, Zink et al. 1983, Katan and Katan 1992, Paris et al. 1993) and Fom-3 in ‘Perlita-FR’ (Zink and Gubler 1985).

‘Dulce’ is another cultivar that is resistant to races 0 and 2 but susceptible to race 1. PI414723-S5 (a ZYMV-resistant selection from PI414723, Danin-Poleg et al. 1997) is susceptible to races 0, 1 and 2.

The objectives of this study were to identify the gene(s) conferring the resistance in ‘Dulce’ and to map the gene(s) for resistance. For gene identification, ‘Dulce’ was crossed with ‘Hemed’ and ‘Doublon’ (Table 1). The parents and their F1 and F2 progenies were inoculated with Fusarium oxysporum f.sp.melonis races 0 and 2 separately. The melon cultivar ‘En Dor’ was used as a susceptible control (Katan and Katan 1992). Identification of the Fusarium race was confirmed using the differentials ‘Doublon’ and ‘Hemed’.

For mapping of the resistance, F2/F3 families of the mapping population (PI414723-S5’Dulce’) were inoculated with fusarium,. From 20 to 42 plants of each of the 104 families were infected with race 0 or race 2 in three separate trials.

All ‘Dulce’, ‘Hemed and ‘Doublon’ plants were, as expected, resistant to Fusarium races 0 and 2 (Table 1). All ‘PI414723’ and ‘En Dor’ plants were susceptible. All F1 and F2 plants resulting from crossing of ‘Dulce’ with ‘Hemed’ and ‘Dulce’ with ‘Doublon’ were resistant to both race 0 and race 2. No susceptible individuals were found among the 644 and 686 F2 plants of the crosses with the two resistant accessions (Table 1). Therefore, the results indicated that the Fusarium resistance in ‘Dulce’ is conferred by the same gene as in ‘Doublon’ and ‘Hemed’, Fom-1.

The segregation of the resistance in the F2/F3 families of the mapping population was 24:51:29 (all resistant:segregants resistant and susceptible : all susceptible, respectively) in accordance with the expected 1:2:1 ratio (X² = 0.52 p=0.77). Resistance was analyzed together with 73 markers and located to linkage group 5. This is in agreement with the previous assignment of Fom-1 to that linkage group (Baudracco-Arnas and Pitrat 1996).

Deviation from the expected segregation ratio was observed in seven of the 51 heterozygous F2/F3 families. In those families 40-53% of the plants were susceptible rather than 25% as expected. We observed the same phenomenon in other germplasm during the last few years. Deviation was previously reported by Baudracco-Arnas and Pitrat (1996). These findings and the non-uniform response of some genotypes to Fusarium wilt may differ among genetic backgrounds.

Table 1. Reaction to inoculation with Fusarium wilt races 0 and 2 in crosses between ‘Dulce’ and ‘Doublon’ nd ‘Dulce; and ‘Hemed’.

Parents and crosses Number of plants
Race 0 Race 2
Resistant Susceptible Resistant Susceptible
Dulce 35 35 35 0
Hemed 49 49 42 0
Doublon 42 42 42 0
PI414723-S5 0 0 0 35
En Dor 0 0 0 35
F1 Dulce x Hemed 301 49 42 0
F2 Dulce x Hemed 343 301 343 0
F2 Dulce x Doublon 343 343 0

Literature Cited

  1. Baudracco-Arnas, S. and M. Pitrat. 1996. A genetic map of melon (Cucumis melo L.) with RFLP, RAPD, isozyme, disease resistance and morphological markers. Theor. Appl. Genet. 93:57-64.
  2. Danin-Poleg, Y. H.S. Paris, S. Cohen, H.D. Rabinowitch, and Z. Karchi. 1997. Oliogenic inheritance of resistance to zucchini yellow mosaic virus in melons. Euphytica 93:331-337.
  3. Katan, T. and J. Katan. 1992. Physiological races of Fusarium wilt of melons in Israel. Hassadeh 72:1105-1106 (in Hebrew).
  4. Mas, P., G. Risser and J.C. Rode. 1969. Phenomenes de premunition entre formes special-isees ou races de Fusarium oxysporum chez Cucumis melo. Annal. Phytopathologie 1:213-216.
  5. Paris, H.S., R. Cohen, Y. Danin-Poleeg and S. Schreiber. 1993. Gene for resistance to fusarium wilt race 1 in Oriental pickling melon. cucurbit Genet. Coop. Rep. 16:422-43.
  6. Risser, G. 1987. Controversey on resistance to Fusarium wilt in ‘Perlita’ Cucumis melo L.). Cucurbit Genet. Coop. Rep. 10:60-61.
  7. Zink, F.W., W.D. Gubler and R.G. Grogan. 1983. Reaction of muskmelon germ plasm to inoculation with Fusarium oxysporum f.sp. melonis race 2. Plant Disease 67:1251-01255.
  8. Zink, F.W. and W.D.Gubler. 1985. Inheritance of resistance in muskmelon to Fusarium wilt. J. Amer. Soc. Hort. Sci.

Contribution No. 177/99 from the Agricultural Research Organization, Newe Ya’ar Research Center, Israel.