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Inheritance of race 1.2 Fusarium wilt resistance in four melon cultivars
- Chikh-Rouhou, Hela, GonzÃ¡lez-Torres, Rafael, Oumouloud, Ali, Alvarez, JosÃ© M.
- Euphytica 2011 v.182 no.2 pp. 177-186
- Fusarium oxysporum, Fusarium wilt, cultivars, heritability, inheritance (genetics), introgression, melons, races
- The resistance to Fusarium oxysporum f.sp. melonis (Fom) race 1.2 has been studied in melons, such as the Portuguese accession âBG-5384â and in the Japanese âShiro Uri Okayamaâ, âKogane Nashi Makuwaâ, and âC-211â, since a good characterization of the resistance is necessary before its introgression into commercial varieties. These four melon accessions showed a high level of resistance to races 0, 1, and 2 of Fom, indicating that the partial resistance to the race 1.2 previously detected may not have been race specific. To determine the mode of inheritance of the resistance to Fom race 1.2, the F1, F2, BCPR, and BCPS generations from the crosses between the four resistant accessions above and âPiel de Sapoâ, a Fom race 1.2 susceptible melon, were developed. They were subsequently inoculated with two Fom isolates, one from the pathotype 1.2Y and the other from the pathotype 1.2W. The area under the disease progress curve was determined for each inoculated plant, and the data were analyzed. We show that the resistance seen in these accessions is polygenically inherited with a complex genetic control because many epistatic interactions were detected. The three epistatic effects; additivityÂ ÃÂ additivity, dominanceÂ ÃÂ dominance, and dominanceÂ ÃÂ additivity are present and significant, with differing magnitudes from one cross to the next. The relatively low heritabilities, and these epistatic effects make difficult the improvement of the resistance, from these sources, through a standard selection procedure.