Search for Sources of Resistance to a Whitefly Transmitted Yellowing Disease in Melon

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Cucurbit Genetics Cooperative Report 14:59-60 (article 22) 1991

F. Nuez, J. Esteva, C. Soria and M.L. Gomez-Guillamon
Dpto. Biotecnologia. Universidad Politecnica de Valencia, Spain; Estacion Experimental “La Mayora”, Algarrobo-Costa (Malaga), Spain

The principal Spanish area for greenhouse vegetable cultivation is the south-east coast. For some time, a yellowing disease has been a serious problem for greenhouse melon cultivation on this area (3, 4, 7). The causal agent of melon yellowing disease could be a virus whose particles are long, flexuous and have a length of 900 nm (6). The transmission and host range of melon yellowing disease and the symptoms of infected plants suggest that this disease is very similar to beet-pseudo-yellows virus and cucumber yellows virus (1, 2, 3, 8).

About 200 accessions of melon were evaluated over a period 1989 under conditions of natural infection (4). The lines of Asiatic origin “Nagata Kin Makuwa” and PI 161375 showed a certain level of inheritable tolerance (5). A Cucumis melo var. agrestis accession and a Spanish landrace which belong to Tendral type showed a high level of resistance (4).

Another 169 melon accessions (Table 1) have been tested in the last two years, 103 of them under conditions of natural infection. Twenty plants of each one of these 103 accessions were tested. The remaining accessions were evaluated using a technique of artificial inoculation which utilizes the vector of yellowing disease causal agent, the greenhouse whitefly (Trialeurodes vaporariorum W.) (7) : “Non viruliferus” whiteflies were placed for 48 h on melon plant leaves with symptoms of yellowing. After this period, groups of 40 whiteflies were removed and transferred to feed for 72 h on the plants of accessions to be tested. These plants had two trye leaves when were inoculated. Later they were removed and transplanted to a greenhouse where they finished their cultivation period under natural conditions. Ten plants of each one of these accessions were tested. The aforementioned C. melo var. agrestis and the Spanish landrace of Tendral type were included among the accessions artificially inoculated.

All the accessions evaluated under conditions of natural infection showed susceptibility to melon yellowing disease. Among those artificialy inoculated only the C. melo var. agrestis accession displayed a high level of resistance as these plants remained symptomless during the entire trial. (Only one plant showed light yellowing symptoms when the tests were finished.)

A considerable effort has been made to find resistance to melon yellowing disease. The present work confirms the existence of one source of resistance in C. melo. This fact opens up hopeful prospects to the melon breeding for resistance to this yellowing disease.

Table 1. Origin of accessions tested for resistance to melon yellowing disease.

Conditions of natural infection

Origin

Accessions Tested
Zimbabwe 4
Spain 53
South of Balkans, USA, Portugal 1
Unknown 27

Conditions of artificial infection
South of Balkans 4
Yugoslavia 17
China 5
USA 2
Libya 10
Zambia 3
Pakistan 20
Turkestan, Hungria, USA, Afghanistan, Creta, Spain 1
Unknown 8

Literature Cited

  1. Cura, V., C. Soria, and M.L. Gomez-Guillamon. 1990. Host range of the causal agent of melon yellowing disease. Cucurbit Genetics Cooperative 13:29-30.
  2. Duffus, J.E. 1965. Beet pseudo-yellows virus, transmitted by the greenhouse whitefly (Trialeurodes vaporarioum). Phytopathology 55:450-453.
  3. Esteva, J., F. Nuez, and J. Cuatero. 1988. Resistance to yellowing disease in wild relatives of muskmelon. Cucurbit Genetics Cooperative 11:52-53.
  4. Esteva, J., F. Nuez, M.L. Gomez-Guillamon/ 1989. Resistance to yellowing disease in muskmelon. Cucurbit Genetics Cooperative 12:44-45.
  5. Esteva, J., F. Nuez, M.L. Gomez-Guillamon. 1990. Control genetico de la tolerancia al amarilleamiento virotico del melon. I Congresso Iberico de Ciencias Horticolas. 19-21 June. Lisboa (in press).
  6. Jorda, C. and A. Alfaro. 1989. El amarillemiento del melon: su diagnolsis. Documentos de Trabajo del V Congresso Nacional de Fitopatologia. Seccion: Etiologia y Epidemiologia (Comunicaciones). Badajoz 17 al 20 de Octubre de 1989.
  7. Soria, C. and M.L. Gomez-Guillamon. 1990. Relationship between the causal agent of melon yellowing disease in the south-east of Spain and his vector. Cucurbit Genetics Cooperative 13:27-28.
  8. Zenbayashi, R., Y. Shimazaki, and Y. Shibukawa. 1984. Studies on cucumber yellows disease. Bulletin of the Saitama Horticultural Experiment Station 13:11-40.