Infection of mungbean seed is more likely to result from localised pod infection than from systemic plant infection

Fuhlbohm, M. J. and Ryley, M. J. and Aitken, E. A. B. (2013) Infection of mungbean seed is more likely to result from localised pod infection than from systemic plant infection. Plant Pathology, 62 (6). pp. 1271-1284. ISSN 0032-0862

Abstract

The ubiquitous fungal pathogen Macrophomina phaseolina is best known as causing charcoal rot and premature death when host plants are subject to post-flowering stress. Overseas reports of M. phaseolina causing a rapid rot during the sprouting of Australian mungbean seed resulted in an investigation of the possible modes of infection of seed. Isolations from serial portions of 10 mungbean plants naturally infected with the pathogen revealed that on most plants there were discrete portions of infected tissue separated by apparently healthy tissue. The results from these studies, together with molecular analysis of isolates collected from infected tissue on two of the plants, suggested that aerial infection of aboveground parts by different isolates is common. Inoculations of roots and aboveground parts of potted mungbean plants at nine moisture x temperature incubation combinations and of detached green pods strongly supported the concept that seed infection results from infection of pods by microsclerotia, rather than from hyphae growing systemically through the plant after root or stem infection. This proposal is reinforced by anecdotal evidence that high levels of seed infection are common when rainfall occurs during pod fill, and by the isolation of M. phaseolina from soil peds collected on pods of mungbean plants in the field. However, other experiments showed that when inoculum was placed with 130 mm of a green developing pod and a herbicide containing paraquat and diquat was sprayed on the inoculated plants, M. phaseolina was capable of partly systemic growth from vegetative tissue into the pods and seeds.


Statistics for USQ ePrint 25155
Statistics for this ePrint Item
Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: © 2013 British Society for Plant Pathology. Published version deposited in accordance with the copyright policy of the publisher.
Faculty / Department / School: No Faculty
Date Deposited: 29 May 2014 03:18
Last Modified: 22 Aug 2014 03:30
Uncontrolled Keywords: charcoal rot; infection; Macrophomina phaseolina; mungbean; seed
Fields of Research : 06 Biological Sciences > 0607 Plant Biology > 060704 Plant Pathology
07 Agricultural and Veterinary Sciences > 0703 Crop and Pasture Production > 070308 Crop and Pasture Protection (Pests, Diseases and Weeds)
06 Biological Sciences > 0605 Microbiology > 060502 Infectious Agents
Socio-Economic Objective: B Economic Development > 82 Plant Production and Plant Primary Products > 8204 Summer Grains and Oilseeds > 820499 Summer Grains and Oilseeds not elsewhere classified
Identification Number or DOI: 10.1111/ppa.12047
URI: http://eprints.usq.edu.au/id/eprint/25155

Actions (login required)

View Item Archive Repository Staff Only