A qPCR Assay for the Fast Detection and Quantification of Colletotrichum lupini.

Tim Kamber,Pierre Hohmann,Thomas Oberhänsli,Christine Arncken,Nachelli Malpica-López,Monika M Messmer,Joris A Alkemade

doi:10.3390/plants10081548

Tim Kamber, Pierre Hohmann + Show 5 more

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https://doi.org/10.3390/plants10081548

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Abstract

White lupin (Lupinus albus) represents an important legume crop in Europe and other parts of the world due to its high protein content and potential for low-input agriculture. However, most cultivars are susceptible to anthracnose caused by Colletotrichum lupini, a seed- and air-borne fungal pathogen that causes severe yield losses. The aim of this work was to develop a C. lupini-specific quantitative real-time TaqMan PCR assay that allows for quick and reliable detection and quantification of the pathogen in infected seed and plant material. Quantification of C. lupini DNA in dry seeds allowed us to distinguish infected and certified (non-infected) seed batches with DNA loads corresponding to the disease score index and yield of the mother plants. Additionally, C. lupini DNA could be detected in infected lupin shoots and close to the infection site, thereby allowing us to study the disease cycle of this hemibiotrophic pathogen. This qPCR assay provides a useful diagnostic tool to determine anthracnose infection levels of white lupin seeds and will facilitate the use of seed health assessments as a strategy to reduce the primary infection source and spread of this disease.

Highlights

White lupin (Lupinus albus L.) belongs to the Fabaceae family; it is cultivated worldwide and could play an important role in sustainable agricultural farming systems
Preliminary tests using internal transcribed spacer regions (ITS) of C. lupini as targets for quantitative real-time PCR (qPCR) assays indicated that they are unsuitable as they showed unspecific results when using DNA from non-target species
The limit of detection (LoD) and limit of quantification (LoQ) were both determined as 0.01 ng C. lupini DNA/reaction (Table 1)

Summary

Introduction

White lupin (Lupinus albus L.) belongs to the Fabaceae family (legumes); it is cultivated worldwide and could play an important role in sustainable agricultural farming systems. Anthracnose is a global threat to white lupin cultivation and is considered a main obstacle to its broader agricultural use, as most white lupin cultivars are susceptible to the disease. The current anthracnose outbreak is caused by globally distributed, highly aggressive C. lupini strains of genetic group II [8,9]. Severe outbreaks of C. lupini mainly occur in temperate zones under warm and humid weather conditions and can lead to high yield losses [10,11]. The pathogen can cause almost total yield loss when the infection is severe and left untreated [10]. The detection of the pathogen in symptomless but infected seeds could improve seed quality management and, help to reduce disease outbreaks in the field

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