Optimal environmental conditions for the infection and development of Puccinia purpurea on sorghum

White, J. A. and Ryley, M. J. and George, D. L. and Kong, G. A. (2014) Optimal environmental conditions for the infection and development of Puccinia purpurea on sorghum. Australasian Plant Pathology, 43 (4). pp. 447-457. ISSN 0815-3191

Abstract

Although rust can reduce grain yields of late-planted sorghum crops in Queensland, little research has been conducted on environmental parameters affecting infection and development. The effects of temperature, leaf wetness period, plant growth stage, urediniospore concentration and darkness period on the development of rust (Puccinia purpurea) on the inbred Sorghum bicolor line IS8525 were evaluated separately by artificial inoculation of plants under controlled conditions. Rust developed between 16 and 28 °C, with the optimum temperature being 20 °C. Disease severity (pustules cm−2) increased as the length of leaf wetness increased from 4 to 24 h. Infection occurred when plants were exposed to full light, full darkness and varying periods of darkness for the first 24 h after inoculation; 16 h of darkness resulted in the highest rust severity. Plants of IS8525 and of the more resistant line IS12539 inoculated 21–49 days after sowing developed higher levels of rust than others inoculated at, or close to, flowering (63 days after sowing). Rust severity also increased with increasing urediniospore concentrations, but leaf death occurred on young plants inoculated with the highest concentration (50 mg 100 mL water−1). The findings of this study have been used to develop an inoculation technique to detect putative pathotypes of P. purpurea in Australia.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Restricted access to Published version in accordance with the copyright policy of the publisher.
Faculty / Department / School: Current - Faculty of Health, Engineering and Sciences - School of Agricultural, Computational and Environmental Sciences
Date Deposited: 05 Jun 2014 02:59
Last Modified: 16 Mar 2015 06:42
Uncontrolled Keywords: artificial inoculation; darkness period; leaf wetness period; plant growth stage; temperature; Urediniospore concentration
Fields of Research : 06 Biological Sciences > 0605 Microbiology > 060501 Bacteriology
07 Agricultural and Veterinary Sciences > 0703 Crop and Pasture Production > 070308 Crop and Pasture Protection (Pests, Diseases and Weeds)
10 Technology > 1001 Agricultural Biotechnology > 100101 Agricultural Biotechnology Diagnostics (incl. Biosensors)
Socio-Economic Objective: E Expanding Knowledge > 97 Expanding Knowledge > 970107 Expanding Knowledge in the Agricultural and Veterinary Sciences
Identification Number or DOI: 10.1007/s13313-014-0292-9
URI: http://eprints.usq.edu.au/id/eprint/25213

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