A Novel Approach to the Design and Analysis of Field Experiments to Study Variation in the Tolerance and Resistance of Cultivars to Root Lesion Nematodes (Pratylenchus spp.)

Reeves, Karyn L. and Forknall, Clayton R. and Kelly, Alison M. and Owen, Kirsty J. and Fanning, Joshua and Hollaway, Grant J. and Loughman, Robert (2020) A Novel Approach to the Design and Analysis of Field Experiments to Study Variation in the Tolerance and Resistance of Cultivars to Root Lesion Nematodes (Pratylenchus spp.). Phytopathology, 110 (10). pp. 1623-1631. ISSN 0031-949X


Abstract

The root lesion nematode (RLN) species Pratylenchus thornei and P. neglectus are widely distributed within cropping regions of Australia and limit grain production. Field experiments conducted to compare the performance of cultivars in the presence of RLN investigate management options for growers by identifying cultivars with resistance, by limiting nematode reproduction, and tolerance, by yielding well in the presence of nematodes. A novel experimental design approach for RLN experiments is proposed where the observed RLN density, measured before sowing, is used to condition the randomization of cultivars to field plots. This approach ensured that all cultivars were exposed to consistent ranges of RLN in order to derive valid assessments of relative cultivar tolerance and resistance. It overcame problems inherent in conventional experimental approaches which can result in biased estimates or the confounding of cultivar yield potential, tolerance and resistance. Using data from a field experiment designed using the new approach and conducted in Formartin, Australia, the analysis of tolerance and resistance was undertaken in a linear mixed model framework. Yield response curves were derived using a random regression approach and curves modelling change in RLN densities between sowing and harvest were derived using splines to model non-linearity. This approach allowed cultivar resistance to be modelled over a consistent range of pre-sowing RLN densities. Groups of cultivars sharing similar resistance levels could be identified. A comparison of slopes of yield response curves of cultivars belonging to the same resistance class identified differing tolerance levels for cultivars with equivalent exposures to both pre-sowing and post-harvest RLN densities. The proposed design and analysis approach allowed tolerance to be established independently of resistance.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Faculty/School / Institute/Centre: Current - Institute for Life Sciences and the Environment - Centre for Crop Health (24 Mar 2014 -)
Faculty/School / Institute/Centre: Current - Institute for Life Sciences and the Environment - Centre for Crop Health (24 Mar 2014 -)
Date Deposited: 14 Sep 2020 00:02
Last Modified: 23 Apr 2021 04:23
Uncontrolled Keywords: disease control and pest management, experimental design, nematology, population biology, random regression analysis, resistance, tolerance
Fields of Research (2008): 07 Agricultural and Veterinary Sciences > 0703 Crop and Pasture Production > 070308 Crop and Pasture Protection (Pests, Diseases and Weeds)
Socio-Economic Objectives (2008): D Environment > 96 Environment > 9604 Control of Pests, Diseases and Exotic Species > 960413 Control of Plant Pests, Diseases and Exotic Species in Farmland, Arable Cropland and Permanent Cropland Environments
B Economic Development > 82 Plant Production and Plant Primary Products > 8205 Winter Grains and Oilseeds > 820507 Wheat
Identification Number or DOI: https://doi.org/10.1094/PHYTO-03-20-0077-R
URI: http://eprints.usq.edu.au/id/eprint/39522

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