Enhancing resistance in Pinus radiata seedlings to terminal crook (Colletotrichum acutatum) using methyl jasmonate and ultraviolet‐C radiation. Issue 4 (21st March 2015)

• Record Type: Journal Article
• Authors: Reglinski, T.; Taylor, J. T.; Ah Chee, A.; Spiers, M.; Cleary, M.
• Is Part Of: Forest pathology. Volume 45:Issue 4(2015:Aug.)
• Page Start: 331
• Page End: 335
• Publication Date: 2015-03-21
• Subjects: Trees -- Diseases and pests -- Periodicals; Trees -- Effect of air pollution on -- Periodicals; Forests and forestry -- Environmental aspects -- Periodicals; 634.9
• DOI: 10.1111/efp.12186
• Languages: English
• ISSNs: 1437-4781

Abstract

<abstract abstract-type="main" id="efp12186-abs-0001"> <title>Summary</title> <p> <italic>Colletotrichum acutatum</italic> is a fungal pathogen that causes terminal crook disease in radiata pine (<italic>Pinus radiata</italic>) seedlings in New Zealand forest nurseries. Symptoms of infection include malformation or death of the growing tip and a stiffening and thickening of the stem. Although the disease can be managed effectively using fungicides, the New Zealand forest industry is interested in alternative control options such as induced resistance. The aim of this study was to evaluate spray application of chitosan (1.4 g/l) or 2.25 m<sc>m</sc> methyl jasmonate (MeJA) and irradiation with UV‐C (2.16 kJ/m<sup>2</sup>) for their potential to induce resistance to terminal crook. The treatments were applied to 4‐month‐old seedlings at 1 week before pathogen inoculation. By the end of the experimental period (42 days after inoculation), there was 80% disease incidence in the controls, with 48% of seedlings exhibiting severe terminal crook symptoms. The most effective treatment (p < 0.05) was MeJA with 16% disease incidence and none with severe symptoms. UV‐C also significantly (p < 0.05) reduced infection with 52% incidence and 20% of seedlings exhibiting severe symptoms. Chitosan did not reduce disease incidence (72%) compared with the control (80%) but did significantly reduce (p < 0.05) disease severity with 28% exhibiting severe symptoms. MeJA was the only treatment that significantly (p < 0.05) reduced the detrimental effects of infection on seedling apical growth and stem diameter. To our knowledge, this is the first report demonstrating the potential for MeJA and UV‐C to control terminal crook in radiata pine.</p> </abstract>