This is the report from a BSPP Incoming Fellowship.
Click here to read more/apply for one yourself.
After my PhD on white lupin (Lupinus albus L.) and anthracnose disease, caused by Colletotrichum lupini, at the research institute of organic agriculture (FiBL, Switzerland) and the university of Hohenheim (Germany), I had the opportunity to continue my research on C. lupini during a three-month fellowship at the University of Bologna. In Bologna I worked at the Department of Agricultural and Food Sciences (DISTAL) under the supervision of associate professor Riccardo Baroncelli, who is a specialist on Colletotrichum evolution and host interaction. The focus of the fellowship was on studying the population structure of C. lupini.
White lupin is a grain legume that is known for its high protein content, nutritional quality, efficient nitrogen fixation and unique ability to form specialized cluster roots that support phosphorus uptake. Despite a severe production decline at the end of the past century, white lupin has seen a recent revival to sustain the demand for plant-based protein and reduce Europe’s dependency on imported soybean. A major problem in (white) lupin cultivation is anthracnose disease, caused by the globally dispersed, seed- and air-borne fungal pathogen C. lupini. Understanding the population structure and evolutionary potential of C. lupini is crucial to design successful disease management strategies.
A collection of seventy-six globally representative C. lupini and related Colletotrichum isolates was genotyped through triple digest restriction-site associated DNA sequencing (3D-RADseq), resulting in a high-resolution dataset. Phylogenetic and structural analysis could distinguish four (I – IV) independent lineages and a high overall standardized index of association (rbarD) indicated that C. lupini reproduces clonally. Isolates representing the four different lineages were tested for virulence on two white lupin and two Andean lupin (L. mutabilis) accessions. This revealed differences in virulence between and within clonal lineages, with lineage II isolates being consistently the most aggressive on white lupin. Isolates belonging to lineage II appeared to have a mini chromosome which was also partly present in lineage III and IV, but not in lineage I isolates. Variation in the presence of this mini chromosome could indicate a role in host interaction. All four lineages were present in the South American Andes region, which was already suggested by others to be the center of origin of this species. Only members of lineage II have been found outside South America since the 1990s, indicating it as the current pandemic population. As a seed-borne pathogen, C. lupini has mainly spread through infected but symptomless seeds, stressing the importance of phytosanitary measures to prevent future outbreaks of strains that are yet confined to South America. We were able to publish the results in Molecular Plant Pathology: https://doi.org/10.1111/mpp.13332.
To control anthracnose disease more sustainably and effectively an integrative approach, including modern breeding efforts, disease prevention strategies and mixed cropping systems is recommended. Further research is required to increase our understanding on white lupin-C. lupini interaction and to identify genetic regions involved in resistance or virulence, respectively, which could support white lupin breeding.
If you are further interested in white lupin and anthracnose disease, here is the link to my thesis: http://nbn-resolving.de/urn:nbn:de:bsz:100-opus-20578.
Dr. Joris A. Alkemade
TOP IMAGE: Canale delle Moline in Bologna.
White lupin pods infected by Colletotrichum lupini.
This is the report from a BSPP Incoming Fellowship.
Click here to read more/apply for one yourself.
