Survival, transmission and control of Phoma koolunga in field pea seed and reaction of field pea genotypes to the pathogen
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Little is known about the epidemiology of Phoma koolunga, a component of the ascochyta blight complex of field pea in southern Australia. The aims of this research were to investigate seed infection, efficacy of fungicides as seed dressings and the reaction of current field pea genotypes to this fungus. The frequency of isolation of P. koolunga from individual seed samples from South Australia, Victoria and Western Australia ranged from 0 to 6 %. Disease was transmitted to 98 % of seedlings that emerged from artificially inoculated seeds (AIS) in growth room conditions. The necrotic index on seedlings that emerged from AIS at 8 °C was greater than that for seedlings at 12, 16 and 20 °C. P-Pickel T® and Jockey Stayer® were the most effective fungicides for reducing disease incidence and severity on seedlings emerged from AIS sown in soil and on germination paper, respectively. The response of 12 field pea genotypes to one isolate of P. koolunga was assessed by spraying plants with pycnidiospore suspension in controlled conditions and examining symptoms from 3 to 21 days post-inoculation (dpi). Genotypes Sturt, Morgan and Parafield showed more severe disease on the lowest three leaves than the other genotypes at 21 dpi. In another experiment, four genotypes of short, semi-leafless type field peas were inoculated with three isolates of P. koolunga which differed in virulence and assessed as described above. Kaspa showed significantly less disease than Morgan or WAPEA2211 at 21 dpi when inoculated with two of the three isolates tested. Isolates of P. koolunga differed in aggressiveness based on % leaf area diseased until 14 dpi, but differences were not significant at 21 dpi.
KeywordsSeed-borne Pisum sativum Ascochyta blight Disease severity Seed treatment Resistance
This research was a part of the PhD project of the first author, supported by a scholarship from Iranian Ministry of Science, Research and Technology. The authors thank Dr. R. Kimber and Mrs. M. Krysinska-Kaczmarek for technical advice, and Dr. Herdina for DNA testing of samples.
- Hawthorne W, Davidson J, Lindbeck K (2010) Pulse Seed treatments & Foliar Fungicides http://www.sardi.sa.gov.au/__data/assets/pdf_file/0005/74921/Pulse_Seed_treatments__and__Foliar_Fungicides_-_7th_Edition.pdf
- Hawthorne W, Davidson J, Mcmurray L, Armstrong E, Macleod B, Richardson HJ (2012) Field pea disease management strategy, Southern and Western region http://www.pulseaus.com.au/pdf/Field%20pea%20Disease%20Management%20Strategy%20Southern%20&%20Western%20Region.pdf
- Hwang SF, Lopetinsky K, Evans IR (1991) Effects of seed infection by Ascochyta spp., fungicide seed treatment, and cultivar on yield parameters of field pea under field conditions. Can Plant Dis Surv 71:169–172Google Scholar
- Kimber RBE, Ramsey MD (2001) Using fungicides to control ascochyta blight of chickpea. Proceedings of the 13th Australasian Plant Pathology Conference. Cairns, QLD, Australia, 199Google Scholar
- Knappe B, Hoppe HH (1995) Investigations on the resistance of peas (P. sativum L.) toward Ascochyta pinodes and Phoma medicaginis var. pinodella. In. Proceedings of the 2nd European Conference on Grain Legumes. Copenhagen, Denmark: AEP, 86–87.Google Scholar
- Moussart A, Tivoli B, Lemarchand E, Deneufbourg F, Roi S, Sicard G (1998) Role of seed infection by the ascochyta blight pathogen of dried pea (Mycosphaerella pinodes) in seedling emergence, early disease development and transmission of the disease to aerial plant parts. Eur J Plant Pathol 104:93–102CrossRefGoogle Scholar
- Priestley RH, Bayles RA, Sweet JB, Knight C, Parry DW, Wright IR, Tierney PI, Kerr SP, Gans PT, Wooster P (1985) Disease assessment manual for crop variety trials. National lnstitute of Agricultural Botany. United Kingdom, CambridgeGoogle Scholar
- Richardson HJ, Leonforte T, Smith AJ (2009) Response of field pea varieties to the fungal components of the ascochyta complex In. The Second International Ascochyta Workshop. Washington, USA: Washington State University, 60.Google Scholar
- Salam MU, Macleod WJ, Pritchard I, Seymour M, Davidson JA, Salam KP, Galloway J, Mcmurray LS, Lindbeck KD, Richardson H (2011b) G2 blackspot manager model to guide field pea sowing for southern Australia in relation to ascochyta blight disease. Australas Plant Pathol 40:632–639CrossRefGoogle Scholar
- Sprague SJ, Burgess DR (2001) Seed treatment to suppress infection of canola seedlings by Leptosphaeria maculans. In: Marcroft SJ, ed. 12th Australian research assembly on brassicas. Geelong, Victoria, Australia, 68–72.Google Scholar
- Tivoli B, Baranger A, Avila CM, Banniza S, Barbetti M, Chen WD, Davidson J, Lindeck K, Kharrat M, Rubiales D, Sadiki M, Sillero JC, Sweetingham M, Muehlbauer FJ (2006) Screening techniques and sources of resistance to foliar diseases caused by major necrotrophic fungi in grain legumes. Euphytica 147:223–253CrossRefGoogle Scholar