Our research is directed on understanding the genetics of edible mushrooms in order to improve breeding efficiency. The focus is on button mushrooms (Agaricus bisporus) and oyster mushrooms (Pleurotus ostreatus). For this we also explore the biological variation within our large collection of varieties (>5000 strains representing 125 species) by assessing genetic relatedness within species and quantifying several phenotypic characteristics.
Other uses of fungi
We also explore the utilisation of fungi for selective degradation of lignin in organic (waste) materials. Research done so far has shown that a number of species degrade substantial portions of lignin while hardly consuming cellulose. These fungi can thus be used to make cellulose bioavailable in low value organic waste, upgrading it into animal feed or feedstock for the production of bioenergy.
Plant Breeding has a large collection of fungi that produce edible mushrooms (the collection contains 5000 strains representing more than 125 species). The focus is on button mushrooms (Agaricus bisporus), oyster mushrooms (Pleurotus spp.) and shiitake (Lentinula edodes).
Phenotyping edible mushrooms
Unifarm has an experimental climate controlled growing facility for small scale production of edible mushrooms. The design allows cultivation comparable to commercial production, and reliable phenotyping (a.o. resistance to diseases, quality, yield, etc.). The rooms are also designed for contained cultivation of genetically modified strains.
Substrate utilisation by button mushrooms
Substrate (compost) is one of the main cost factors in button mushroom production. Research is directed to unravel the way vegetative mycelium is degrading organic matter and how this is used for the formation of mushrooms. This knowledge is used to improve the efficiency of the cultivation system. In addition, the biological variation in the collection is used to improve the substrate utilisation by commercial varieties.
Breeding: mapping traits in segregating populations
The mushroom research group generates segregating populations for traits relevant for the primary producers (yield, quality, disease resistance) or consumers (taste, bioactive compounds, etc.). Linkage maps are generated using SNP markers or GBS (genotyping by sequencing). Markers linked to traits are subsequently used for selection in offspring. An example of a breeding product of the group is a sporeless oyster mushroom.
Button mushrooms as a model for studying meiosis
Button mushroom is represented by two compatible subspecies differing in the interchromosomal crossovers. In commercial lines and most wild isolates, crossovers are mainly restricted to chromosome ends whereas in the other subspecies crossovers take place over the entire chromosome. Segregating populations are used now to study mechanisms behind these two recombination landscapes. This might generate knowledge to control meiosis either to enhance or retain allele combinations.
Mushrooms and biobased economy
The utilisation of lignocellulose is limited by the presence of recalcitrant lignin. Physical and chemical pretreatments are now used to reduce/modify lignin and enhancing the access to (hemi)cellulose. White rot fungi (including many edible fungi) selectively degrade lignin during vegetative growth and can thus be used to valorise lignocellulose in a low tech, low cost and sustainable way.
Research is directed to:
- Screening optimal fungal-organic matter combinations
- Optimize conditions for selectively degrading lignin
- Using biological diversity within each fungal species to optimize lignin degradation (including breeding)
Genetic regulation of mushroom formation
Genes that are differentially expressed in vegetative growth and initiation of mushrooms (pins) are overexpressed or knocked-out using Atum transformation (via cross-over and CRISPR-Cas). The aim is to unravelling the mechanism of mushroom formation which allows a better control of a mushroom crop and might lead to the commercial production of until now non-cultivable mushroom species.
Critical factors involved in primordia building in agaricus bisporus : A reviewMolecules 25 (2020)13. - ISSN 1420-3049
Prospects and feasibility of fungal pretreatment of agricultural biomass for ruminant feedingAnimal Feed Science and Technology 268 (2020). - ISSN 0377-8401
Preference of fresh and stored Ceriporiopsis subvermispora and Lentinula edodes treated wheat straw by goatsLivestock Science 236 (2020). - ISSN 1871-1413
Wheat bran addition improves Ceriporiopsis subvermispora and Lentinula edodes growth on wheat straw, but not delignificationAnimal Feed Science and Technology 259 (2020). - ISSN 0377-8401
Quality assurance program in HBM4EU: first results and future challenges
Variation in the fungal pretreatment of wheat straw into ruminant feedIn: Book of Abstracts IFTC 2019 - 1st International Feed Technology Congress. - - p. 15 - 16.
Evaluation of fungal degradation of wheat straw cell wall using different analytical methods from ruminant nutrition perspectiveJournal of the Science of Food and Agriculture 99 (2019)8. - ISSN 0022-5142 - p. 4054 - 4062.
The nutritional value of the lower maize stem cannot be improved by ensiling nor by a fungal treatmentAnimal Feed Science and Technology 247 (2019). - ISSN 0377-8401 - p. 92 - 102.
Improving ruminal digestibility of various wheat straw types by white-rot fungiJournal of the Science of Food and Agriculture 99 (2019)2. - ISSN 0022-5142 - p. 957 - 965.
Mechanistic insight in the selective delignification of wheat straw by three white-rot fungal species through quantitative 13C-IS py-GC–MS and whole cell wall HSQC NMR: Wageningen University and Research