The relationship between genotypes of three Brassica species and collections oi Plasmodiophora brassicae

Abstract

internationally collected data concerned with variation for pathogenicity in Plasmodiophora cKssicae and for clubroot resistance in three Brassica species, together with additional experimental evidence, were used to elucidate the major genetic features of this host-parasite relationship. The major components of resistance in B. campestris and B. napus were differential and xobahly oligogenic. Good agreement was found between the data and simple gene-for-gene schemes. In contrast, the major component of resistance in most B. oleracea genotypes appeared -. 0 be non-differential and there was evidence of pathogen variability for non-differential pathogenicity. A strong association between pathogenicity on any resistant B. campestris genotype and or. all resistant B. napus genotypes was apparent, suggesting the possibility of genes in common. There was evidence that P. brassicae collections carrying certain characters for differential pathogenicity on these two species were less pathogenic on B. oleracea. However, there was no ether evidence of pathogenic specialization to a particular host species. Several analytical pro-Mdures were employed which may prove useful in clarifying the important features of other host-parasite combinations.

Use of rooted leaves for screening of Brassica germplasm response to clubroot (Plasmodiophora brassicae) and downy mildew (Hyaloperonospora parasitica)

“…The first, ECD set, is identical with the one recommended as European Clubroot Differential (CRUTE et al 1983) having been previously used for the evaluation of Plasmodiophora races in the Czech Republic (ROD 1994). The second group consisted of experimental cauliflower (Brassica oleracea var.…”

Variability in resistance to clubroot in European cauliflower cultivars

“…European field isolates of clubroot disease display a great genetic variation, and frequently consist of several pathotypes. Studies focused on the testing of resistance against clubroot demonstrated that P. brassicae isolates have a high potency to overcome resistance of all B. oleracea ECD hosts (Crute et al 1983;Diederichsen et al 2009). Clubroot disease is controlled most effectively by cultivation of resistant cultivars.…”

Inheritance of Resistance to Clubroot (Plasmodiophora brassicae Wor.) in Kale (Brassica oleracea ssp. Acephala)

“…Several workers succeeded in proving that the relationship between the cultivar Badger Shipper and P. brassicae is differential (CHIANG and CRETE 1970;CRUTE et al 1983). While most authors think that many genes are involved in the genetic control of resistance in other genotypes, YOSHIKAWA (1983), who worked on progenies of crosses between cultivar Bohmerwaldkohl and a susceptible cabbage, demonstrated that 1 to 4 genes control this character.…”

“…Some disagreements remain about the exact number of genes involved (BROKENSHIRE 1982;CRUTE et al 1983;GUSTAFSSON and FALT 1986). Of interest are the results of WILLIAMSON (1984WILLIAMSON ( , 1987, who worked on the same B. napus plants with many pathogen populations, and revealed the existence of nondifferential interactions.…”

“…capitata): Badger Shipper, Bindsachsener, Bohmerwaldkohl, and their self-progenies. The authors usually conclude that the inheritance of resistance to clubroot in B. oleracea is quantitative and involves recessive alleles (SEAMAN et al 1963: WEISAETH 1974CRUTE et al 1983;VOORIPS andVISSER 1991). CHIANG andCRETE (1976) analyzed a 4 x 4 diallel and demonstrated a high level for broad sense heritability with mostly additive genetic effects.…”