Woronin Plasmodiophora brassicae Nov10 Dr Caroline Donald; e-mail: [email protected]; Phone: (03) 92109299 (03) Phone: [email protected]; e-mail: Donald; Caroline Key Contact: Dr See control. and detection breeding, resistance biology, impac economic including reviews comprehensive nine Further Reading: obligatebiotroph caused by the soilborne andmuch of cropsinCanada Europe. It is it isan important economically disease of oilseedbrassica production. Todate clubroot threat to oilseedbrassica in Australia. It ispotentially aserious is anda widespread serious disease of vegetablebrassicas Clubroot subject of ongoing debate and changes constantly). Plasmodiophoraceae. (Note: the taxonomyof thisor Classification: Disease Donald,DPIVictoria. and Caroline zoosporangium (d); from Cells a root numerous gallcontaining resting spores (e). Photo credits: Ian Porter Zoospore release from broccoli (b); Broccoli root withroot hairs containing zoosporangia (arrows) (c); Fig. 1. a Distribution: released into soilas root material decays. containing resting spores. Resting spores are hypertrophy andthe formationof root galls secondaryplasmodia causingcell developing zoospores penetrate the cortical tissues secondary zoosporesare formed. These cleavage zoosporangia containing 4-16 and nucleardivision plasmodium. Following penetrates roothairs toprimarya form release azoospore singlebiflagellate which a suitable host resting spores germinate to survive insoilfor many years. In the presence of (secondary)can infection.spores Resting in soil, root hair (primary) infection and cortical P. brassicae interaction of this pathogen withitshosts. and about thelifecycle unknown taxonomy,full 1878. More than 130years later much remains in byWoronin identified as the cause of clubroot brassicae Plasmodiophora European history dating history backtoEuropean the 13 The Pathogen: Affected cabbage crop Chinese showingtypicalsymptomsof stunting (a); and wilting Rooton galls : Pathogen ofthemonth Pathogen ofthemonth has a has three stagelifecycle: survival Widespread worldwide. In 2009 the Journal of Plant Growth Regulation pr Regulation Growth Plant of 2009Journal In the lbotdisease hasa Clubroot Clubroot K: Protozoa, P: Cercozoa, C: Phytomyxea, F:O: Plasmodiophorida, bc was formally th century. century. lsoipoabrassicae Plasmodiophora t, lifecycle, metabolism and hormone action, molecular molecular and action, hormone metabolism t, lifecycle, Journal of Plant Growth Regulation (2009) 28 (3) 193-303. (3) 28 (2009) Regulation ofPlant Growth Journal ganism, even the Kingdom to itbelongs,which is the and weeds rape, mustard, swede), cabbage, turnip,bok-choy), sprouts),cauliflower, Brussels crop species including on species within the family Brassicaceae symptomsare Typical Host Range: observed only manage clubroot, particularly invegetable crops. multifaceted or integrated approach isbeingused to forcultivars are available some crops. Increasingly, a diseaseand resistant to predictdeveloped clubroot chemical application.Molecular tests havebeen amendments, manipulation of soilpH (to 7.0-7.5) and measures, includingcrop rotation, calcium andboron pathogen system isresponsive to a range of control and water through improved farm hygiene.The host- be limitedbyrestricting the movement of infested soil Detection andcontrol: 11% worldwide. Brassica crops causing estimated in-field losses of Impact: thaliana. Arabidopsis (shepherd’s purse)and bursa-pastoris Capsella has not been reported inAustralian canolahowever, oduced a special clubroot edition. It contains Itcontains edition. oduced clubroot a special lbotisthe mostsignificantdisease of Clubroot ahnsraphanistrum Raphanus – – B. oleracea November 2010 November 2010 Woronin. d B. juncea Spread of the pathogen can (broccoli, cabbage, B. napus B. rapa e (Indian mustard), (wild radish),(wild (canola, fodder (Chinese