Phoma koolunga Davidson, Hartley, Priest, Krysinska- Kaczmarek, Herdina, McKay & Scott DEC09 Australia. Mycologia, 101(1): 120-128.. 101(1): Mycologia, Australia. ( peas field on symptoms blight ascochyta causes Phoma of species new A (2009) E.S. Jenny Davidson; e-mail: jenny.david Key e-mail: Contact: Davidson; Jenny Davidson, SouthDavidson, Australia. Further Reading: by acomplexof fungi. Ascochyta blight (synonym: blackspot) is the most serious diseaseof wideandis field peasworld caused Classification: Disease Fig. 1. Culture ofCulture control isdependenton agronomic measures Australia. Major gene resistance hasnot beendetected and fungicides areoften uneconomic.Disease (150–210 to olivaceous. reversePycnidia yellow-brown withlittleolivaceous or no aerialmycelium, orgray aerial dark mycelium, isoccasionally On malt agar the colony haswhite to pale symptoms on field peas. Australia, and causes typical ascochyta blight described by Davidson The Pathogen: Australia, particularly inSouthAustralia. detected in the pea growingareasof Distribution: koolunga and Ascochyta pisi pinodes on blight field peasi.e. from the other causal agents of ascochyta cultural growth distinguishes the pathogen P. koolunga, The comparativelylargesize of the conidia of radiating lines. pseudo-sclerotia maybe present, formed in aseptate. are absent Chlamydospores but tooblong, 12.5–17xellipsoidal 5–7 agar or are immersed. hyaline, Conidia soht blight symptoms on withconidiaoffield peasinoculated artificially Ascochyta : , Phoma medicaginis Phoma koolunga has been identified. µ m diameter) are scattered over the Pathogen ofthemonth Pathogen ofthemonth hi spaenature and the their aseptate Phoma koolunga Davidson, J.A., Hartley, D., Prie Phoma koolunga Ascochyta blight complex of field peas K: Fungi,D: Ascomycota, C: O:Euascomycetes, Pleosporales, F: Pleosporaceae. . No teleomorph of P. Phoma koolunga Mycosphaerella et al grown on PDA(b); of Conidia (2009) inSouth var. has been pinodella was first µ m, mostly has recently beenidentifiedas part of inSouth this complex such asdelayedsowingandwiderotations. st, M., Krysinska-Kaczmarek, M., st, M., Krysinska-Kaczmarek, [email protected]; Phone: (08) 8303 Phone: (08) [email protected]; between peacrops to reduce soil-borneinoculum. crop management, particularlywide rotations ITS region. options areControl limitedand involve morphology andspecific PCR primersbased on the Detection andcontrol: are grown inshort rotations. prominent in peathe crops diseasecomplexwhere stubble. Thisimpliesthe bemore pathogen will or directlyon probably inthe form of pseudosclerotia disease. P. koolunga loses an averageof 10% production due to this estimated that each year the Australianpea crop epidemics canbe ashigh50%, it while hasbeen insevere Yieldlosses plants. present onindividual detected within onepaddock and are often all ascochyta blight on be field peascan usually caused by trials the fromsymptoms are indistinguishable those infected peas in the field. In glasshouse inoculated severe ascochytablight symptoms innaturally Impact: P. koolunga littoralis can be produced on some cultivarsof inglasshouse major hostconditions symptoms while Fieldpeas Host Range: ( Pisum sativum Phoma koolunga , M. scutella M. pinodes. – – December 2009 December 2009 and Lensculinaris has been associated with is able to survive inthe soil, . (c) Herdina, McKay, A. and Scott, A. and Herdina,McKay, All the causal agentsof Diagnosis includesculturalDiagnosis Pisum sativum Photo credits: Jenny Phoma koolunga Medicago . ) in in South ) ) are the the ) are (a);