Mechanisms of resistance in Brassica carinata, B. napus and B. juncea to Pseudocercosporella capsellae

Gunasinghe, N. ORCID: and You, M. P. and Clode, P. L. and Barbetti, M. J. (2016) Mechanisms of resistance in Brassica carinata, B. napus and B. juncea to Pseudocercosporella capsellae. Plant Pathology, 65 (6). pp. 888-900. ISSN 0032-0862


Studies were undertaken to compare susceptible and resistant host responses to Pseudocercosporella capsellae in cotyledons of Brassica carinata, B. juncea and B. napus in order to define the mechanisms of resistance in these three species. On both resistant and susceptible hosts, hyphal penetration was always through stomatal openings and without infection pegs or appressoria. On resistant B. carinata ATC94129P, up to 72% of spores disintegrated and, generally, germination (<22%) and germ tube lengths (<25 μm) were comparatively low. Resistant B. napus Hyola 42 had the lowest germination (8%) and susceptible B. carinata UWA#012 had the highest (51%). On resistant B. carinata ATC94129P, germ tube extension was impeded across 24–60 h post‐inoculation (hpi) and percentage stomatal penetration lower (4%) at 60 hpi compared with susceptible B. carinata UWA#012 (26%). Stomatal densities (stomata/14 757 μm2) on resistant B. juncea Dune (2·12) and B. napus Hyola 42 (1·62) were lower than for susceptible B. juncea Vardan (2·40) and B. napus Trilogy (2·03). Resistant B. carinata ATC94129P had greater stomatal density (1·89) than susceptible B. carinata UWA#012 (1·58). Overall, B. juncea had greater stomatal density (2·26) compared with B. napus (1·83) and B. carinata (1·74). In resistant B. carinata ATC94129P, P. capsellae induced 28% stomata to close, while in susceptible B. carinata UWA#012 no such closure was induced. Epicuticular wax crystalloids were present only on resistant B. carinata ATC94129P and probably also contribute towards resistance.

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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Faculty/School / Institute/Centre: No Faculty
Faculty/School / Institute/Centre: No Faculty
Date Deposited: 09 Feb 2021 00:28
Last Modified: 10 Feb 2021 06:10
Uncontrolled Keywords: Brassica carinata, Brassica juncea, Brassica napus, Pseudocercosporella capsellae, resistance mechanisms, white leaf spot
Fields of Research (2008): 06 Biological Sciences > 0607 Plant Biology > 060704 Plant Pathology
06 Biological Sciences > 0605 Microbiology > 060505 Mycology
07 Agricultural and Veterinary Sciences > 0703 Crop and Pasture Production > 070308 Crop and Pasture Protection (Pests, Diseases and Weeds)
Fields of Research (2020): 31 BIOLOGICAL SCIENCES > 3107 Microbiology > 310705 Mycology
31 BIOLOGICAL SCIENCES > 3108 Plant biology > 310805 Plant pathology
30 AGRICULTURAL, VETERINARY AND FOOD SCIENCES > 3004 Crop and pasture production > 300409 Crop and pasture protection (incl. pests, diseases and weeds)
Socio-Economic Objectives (2008): D Environment > 96 Environment > 9604 Control of Pests, Diseases and Exotic Species > 960403 Control of Animal 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 > 820502 Canola
B Economic Development > 82 Plant Production and Plant Primary Products > 8298 Environmentally Sustainable Plant Production > 829899 Environmentally Sustainable Plant Production not elsewhere classified
Socio-Economic Objectives (2020): 26 PLANT PRODUCTION AND PLANT PRIMARY PRODUCTS > 2603 Grains and seeds > 260302 Canola
28 EXPANDING KNOWLEDGE > 2801 Expanding knowledge > 280101 Expanding knowledge in the agricultural, food and veterinary sciences
26 PLANT PRODUCTION AND PLANT PRIMARY PRODUCTS > 2605 Horticultural crops > 260512 Protected vegetable crops
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