The scope for nuclear selection within Termitomyces fungi associated with fungus-growing termites is limited

摘要: We investigate the scope for selection at level of nuclei within fungal individuals (mycelia) mutualistic Termitomyces cultivated by fungus-growing termites. Whereas in most basidiomycete fungi number and kind is strictly regulated to be two per cell, mycelia cell highly variable. hypothesised that natural on these not only occurs between mycelia, but also mycelium. test this hypothesis using vitro tests with five nuclear haplotypes a species. First, we studied transition from mixture homokaryons (mycelia identical nuclei) each different haplotype heterokaryons genetically nuclei). In cultivation multiple asexual transfers led formation heterokaryotic reduction mycelial diversity over time. All contained exactly types nucleus. The success heterokaryon during was mainly determined spore production lesser extent growth rate. Second, invariably produced more spores than implying will outcompeted. Third, no homokaryotic ‘escapes’ via were found, despite extensive genotyping. Fourth, contrast fungi, sp. migration mating, limiting competition Our experiments demonstrate species nucleus an established mycelium limited. Although ‘mate choice’ particular possible infer primarily (heterokaryons).