Plasmodiophora brassicae Woronin, 1877
clubroot
on Brassicaceae
Brassica oleracea, Nieuwer ter Aa, 16.x.2018 © Arnold Grosscurt: three kohlrabis with galled roots
detail of the gall
transverse section through the gall

Brassica oleracea, United States © Robert Wick, University of Massachusetts, Bugwood.org
gall
the root collar and roots are strongly swollen, spindle-shaped; there is no gall chamber.
host plants
Brassicaceae, broadly oligophagous:
Aethionema saxatile; Alliaria petiolata; Alyssoides utriculata; Alyssum alyssoides, desertorum, montanum; Arabidopsis arenosa, suecica, thaliana; Arabis; Armoracia rusticana; Aubrieta columnae, deltoidea, pinardii; Aurinia petraea, saxatilis; Barbarea stricta, verna, vulgaris; Berteroa incana; Biscutella auriculata, didyma, laevigata; Brassica oleracea; Braya alpina; Bunias erucago, orientalis; Calepina irregularis; Camelina; Capsella bursa-pastoris, orientalis, rubella; Cardamine amara, parviflora, pratensis; Cardaria draba; Coclearia anglica, danica, groenlandica, officinalis; Coincya monensis subsp. cheirantho, wrightiis; Conringia orientalis; Crambe abyssinica, maritima, tataria; Descuriania sophia; Diplotaxis erucoides; Draba; Erophila verna; Eruca vesicaria; Erucastrum gallicum, nasturtiifolium; Erysimum cheiranthoides, cheiri, crepidifolium, hieraciifolium, odoratum; Hesperis kotschyana, matronalis, tristis; Hirschfeldia incana; Iberis; Isatis glauca, praecox, tinctoria; Lepidium campestre, coronopus, densiflorum, didymum, ruderale, sativum, viriginium; Lobularia maritima; Lunaria annua, rediviva; Malcolmia africana, flexuosa, maritima, orsiniana subsp. angulifolia; Matthiola incana, longipetala subsp. bicornis, tricuspidata; Myagrum perfoliatum; Nasturtium; Neslia paniculata; Petrocallis pyrenaica; Raphanus raphanistrum & subsp. rostratus, sativus; Rapistrum perenne, rugosum; Rorippa austriaca, islandica, sylvestris; Sinapis alba, arvensis & subsp. allionii; Sisymbrium; Syrenia cana; Thlaspi.
References to Papaver, Reseda and especially Fragaria by Klenke & Scholler need further confirmation.
notes
a pest on cultivated plants: “clubroot”
references
Buhr (1964b), Coulianos & Holmåsen (1991a), Klenke & Scholler (2015a), Redfern & Shirley (2011a), Roskam (2009a, 2019a).