Cucurbit Genetics Cooperative Report 16:37-38 (article 12) 1993
F. Nuez, J. Esteva
Depto. Biotecnologia. Universidad Politecnica de Valencia (UPV), SPAIN, Dpto. Ingenieria Aplicada. Universidad de Murcia, SPAIN
Melon dieback is a serious vine decline disease of melon in Spain (2, 3). The primary origin of this disease has been attributed to several ground fungus [Rhizoctonia solani (1), Acremonium sp. (4) and Monosporacsus cannoballus (6)]. Melon dieback etiology associated with Acremonium sp. has been smartly by the Department of Plant Production of UPV (5). Inoculation with this fungus in hydroponic culture conditions produces root rot on melon seedlings (4). Nevertheless this technique seems not to be effective to carry out a screening of resistant genotypes to melon dieback. While these difficulties persist, a possible way to localize sources for resistance is to work in the field conditions.
We have evaluated the response of 47 melon accessions to melon dieback in field conditions during spring-summer season of 1992. The trials were carried out in two locations (Puzol and Romani) in Valencia (Spain). In both places plants were grown in plots where the disease had previously been noted during 1991. The majority of evaluated accessions are Spanish landraces belonging to ‘Amarillo”, ‘Rochet’, and ‘Piel de Sapo’ types. The number of replicate was four per each accession of the ‘Amarillo’ type and three for the rest of the accessions (Table 1). The number of plants per replicate was variable. It was sown in May. Affected plants during July and August were registered. The endof the trial was in the middle of August.
The following data summarize the incidence of melon dieback in this trial:
- Number of accessions with an incidence higher than 50% in both locations: 21.
- Number of accessions with an incidence higher than 50% in one location: 19.
- Number of accessions with an incidence lower than 50% in both locations: 7.
The accession No. 6 (“Cantaloupe” type) stand out among the accessions with an incidence lower than 50% in both locations (Table 1). This accession showed a consistent response although it did not escape completely to the disease. This could indicate that this accession has a notable degree of resistance to melon dieback and it could have interest as source for resistance. This should be confirmed in further trials. The accessions No. 12 and No. 18 (“Amarillo” type) could be employed as direct use materials. On the other hand the use of plots where the disease had previously been noted could be feasible as previous trial for the screening of sources for resistance, according to the results of this work.
Table 1. Accessions with an incidence lower than 50% in both locations.
Location* |
||||||||||
Puzol |
Romani |
|||||||||
Accession |
Incidence** |
R1 |
R2 |
R3 |
R4 |
R1 |
R2 |
R3 |
R4 |
|
| 6 | a | 4 | 4 | 4 | 4 | 4 | 3 | 2 | 3 | |
| 6 | b | 0 | 0 | 0 | 0 | 0 | 0 | 2 | 0 | |
| 7 | a | 3 | 4 | 4 | 4 | 4 | 3 | 3 | 4 | |
| 7 | b | 1 | 0 | 1 | 0 | 1 | 2 | 0 | 4 | |
| 12 | a | 4 | 4 | 4 | 4 | 3 | 3 | 4 | 3 | |
| 12 | b | 1 | 3 | 1 | 0 | 0 | 1 | 3 | 0 | |
| 18 | a | 1 | 4 | 4 | 6 | 3 | 4 | 4 | 4 | |
| 18 | b | 0 | 0 | 0 | 4 | 2 | 0 | 1 | 0 | |
| 43 | a | 4 | 5 | 4 | — | 4 | 4 | 2 | — | |
| 43 | b | 2 | 1 | 0 | — | 2 | 3 | 0 | — | |
| 28 | a | 4 | 5 | 3 | — | 4 | 5 | 6 | — | |
| 28 | b | 3 | 1 | 0 | — | 2 | 2 | 2 | — | |
| 30 | a | 5 | 2 | 1 | — | 1 | 2 | 2 | — | |
| 30 | b | 0 | 1 | 0 | — | 0 | 2 | 0 | — | |
*R: replicate
**a: tested plants
b: affected plants
Literature Cited
- Cebolla, V., T. Campos, and M. Garzia. 19990. Rhizoctonia solani Kuhn, causante del colapso del melon en el Pais Valenviano. Actas de Horticultura 2:150-155.
- Esteva, J. F. Nuez, and J. Garcia-Jimenez. 1992 . Search for sources of resistance to a melon dieback disease in Spain. Cucurbit Genetics Cooperative 15:55-56.
- Garcia-Jimenez, J., A. Alfaro, J. Esteva, F. Nuez, and M.T. Velazquez. 1991. Resistance to Acremonium sp. in Spanish landraces of melon. Cucurbit Genetics Cooperative 14:49-50.
- Garcia-Jimenez, J., M.T. Velaquez and A. Alfaro. 1991. Acremonium sp., agente causal del copapso del melon en el Levante Espanol. In Moral de la Vega (Ed.), Estudios de Fitopatologia. Actas del V Congresso Nacional de Fitopatologia. Octubre de 1989. Badajoz (Spain): 68-72.
- Jimenez, R. M. 1991. Enfermedades causadas por hongos en la horticultura espanola. In Rallo, L., F. Nuez (Eds.). La horticultura espanola en la C.E. Sociedad Espanola de Ciencias Horticolas: 378-383.
- Lobo, M. 1991. Las graves alteraciones de melonares y sandiares. Bol. San. Veg. Plagas 17:133-163.