New insights into the life cycle of the wheat powdery mildew: direct observation of ascosporic infection in Blumeria graminis f. sp. tritici

Jankovics, Tünde and Komaromi, Judit and Fabian, Attila and Jager, Katalin and Vida, Gyula and Kiss, Levente (2015) New insights into the life cycle of the wheat powdery mildew: direct observation of ascosporic infection in Blumeria graminis f. sp. tritici. Phytopathology, 105 (6). pp. 797-804. ISSN 0031-949X

Abstract

Although Blumeria graminis is an intensively studied pathogen, an important part of its life cycle (namely, the way ascospores initiate primary infections on cereal leaves) has not yet been explored in detail. This study reports, for the first time, the direct observation of this process in B. graminis f. sp. tritici using light and confocal laserscanning microscopy. All the germinated ascospores produced a single germ tube type both in vitro and on host plant surfaces; therefore, the ascosporic and conidial germination patterns are markedly different in this fungus, in contrast to other powdery mildews. Germinated ascospores penetrated the epidermal cells of wheat leaves and produced haustoria as known in the case of conidial infections. This work confirmed earlier studies reporting that B. graminis chasmothecia collected from the field do not contain mature ascospores, only asci filled with protoplasm; ascospore development is induced by moist conditions and is a fast process compared with other powdery mildews. Although ascosporic infections are frequent in B. graminis f. sp. tritici in the field, as shown by this study and other works as well, a recent analysis of the genomes of four isolates revealed the signs of clonal or near-clonal reproduction. Therefore, chasmothecia and ascospores are probably more important as oversummering structures than genetic recombination factors in the life cycle of this pathogen.


Statistics for USQ ePrint 31883
Statistics for this ePrint Item
Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Permanent restricted access to Published version due to publisher copyright policy.
Faculty / Department / School: No Faculty
Date Deposited: 25 May 2017 01:49
Last Modified: 02 Nov 2017 04:47
Uncontrolled Keywords: Blumeria graminis; Blumeria graminis f. sp. tritici; Erysiphales; Fungi; Triticum aestivum; Ascomycetes; cereal; cytology; fungus spore; genetics; microbiology; physiology; plant disease; plant leaf; wheat; Ascomycota; cereals; plant diseases; plant leaves; spores, fungal; Triticum
Fields of Research : 06 Biological Sciences > 0605 Microbiology > 060505 Mycology
Socio-Economic Objective: E Expanding Knowledge > 97 Expanding Knowledge > 970106 Expanding Knowledge in the Biological Sciences
Identification Number or DOI: 10.1094/PHYTO-10-14-0268-R
URI: http://eprints.usq.edu.au/id/eprint/31883

Actions (login required)

View Item Archive Repository Staff Only