Euphytica (1997) 93, 31-39

Roeland E. Voorrips and H. Jos Kanne (1997)
Genetic analysis of resistance to clubroot (Plasmodiophora brassicae) in Brassica oleracea. I. Analysis of symptom grades
Euphytica 93 (1), 31-39
Abstract: The inheritance of resistance to clubroot, caused by Plasmodiophora brassicae, in Brassica oleracea was studied in the F₁, F₂ and backcross progenies of four crosses between resistant and susceptible doubled haploid lines. The disease severity was scored visually on a 0-3 scale of symptom grades. These were analyzed qualitatively and quantitatively. The qualitative analysis involved the conversion of symptom grades to a classification as resistant or susceptible, and segregation ratios were used to test several simple genetic models. The quantitative analysis was based on a threshold model, in which symptom grades are considered to arise from splitting a continuous response range into disjoint intervals. This analysis was based on the maximum likelihood method, and several genetic models were evaluated.
Of the four resistances studied, one was shown to be largely determined by two complementary genes. Two other resistances were also shown to be probably controlled by two genes, but the mode of inheritance was not determined unambiguously. The fourth resistance appeared to be determined by more than two genes.
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Link to article at publishers website
Database assignments for author(s): Roeland E. Voorrips

Research topic(s) for pests/diseases/weeds:
resistance/tolerance/defence of host

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Plasmodiophora brassicae	Cabbage (Brassica oleracea)