Morphological and Pathogenic Characterization of Genetically Diverse Sclerotinia Isolates from European Red Clover Crops (Trifolium Pratense L.). Issue 4 (6th December 2012)

• Record Type: Journal Article
• Authors: Vleugels, Tim; Baert, Joost; van Bockstaele, Erik
• Is Part Of: Journal of phytopathology. Volume 161:Issue 4(2013:Apr.)
• Page Start: 254
• Page End: 262
• Publication Date: 2012-12-06
• Subjects: Plant diseases -- Periodicals; 632
• DOI: 10.1111/jph.12056
• Languages: English
• ISSNs: 0931-1785

Abstract

<abstract abstract-type="main" id="jph12056-abs-0001"> <title>Abstract</title> <p>Clover rot, an important disease in European red clover crops, is caused by <italic>Sclerotinia trifoliorum</italic> or <italic>Sclerotinia sclerotiorum</italic>. Until today, little is known about the variation in aggressiveness among <italic>Sclerotinia</italic> isolates from red clover. Aggressiveness has never been correlated with morphological characteristics. Rapidly growing isolates may be more aggressive, but this was never investigated in <italic>S. trifoliorum</italic> before. Also nothing is known about the link between sclerotia production and aggressiveness. Oxalic acid is an important pathogenicity factor in <italic>Sclerotinia</italic> species, but its effect on aggressiveness is unknown in <italic>S. trifoliorum</italic> isolates. For this study, we selected 30 <italic>Sclerotinia</italic> isolates from 25 locations Europe: 26 <italic>S. trifoliorum</italic> isolates and 4 <italic>S. sclerotiorum</italic> isolates from two locations in France (Fr.A and Fr.B). For each isolate, the <italic>in vitro</italic> growth speed, sclerotia production, oxalate production and aggressiveness were analysed and correlations were estimated between aggressiveness and the other characteristics. Aggressiveness was assessed <italic>in vitro</italic> on detached leaves and in a greenhouse on young plants. Our isolates differed significantly in growth speed, sclerotia production, oxalate production and aggressiveness. The infections on detached leaves and young plants revealed interaction between isolates and plant genotypes and between isolates and cultivars, but there was no indication that pathotypes exist. <italic>In vitro</italic> growth speed and <italic>in vitro</italic> aggressiveness on detached leaves were positively correlated with aggressiveness on young plants, while sclerotia production was negatively correlated with aggressiveness on young plants. These factors can be used as predictors of aggressiveness of <italic>Sclerotinia</italic> isolates from red clover crops.</p> </abstract>