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Abstract
The classic filamentous fungus Neurospora crassa propagates asexually through the dissemination of conidia. These spores are produced through specialized structures called conidiophores. While the genetic, environmental, and circadian cues guiding conidiophore development are well understood, little is known about the morphological variation of these structures, particularly in wild populations. In other filamentous fungi, conidiophore architecture has been shown to impact both spore dispersal patterns and pathogenicity. This dissertation utilizes a wild population collection of 21 strains from Louisiana, USA to explore natural conidiophore morphological variation. We identified three novel and distinct architectural phenotypes, named Wild-Type (WT), Wrap, and Bulky, that are upheld throughout conidiophore development. We show that these phenotypes have ecological implications through sporulation and germination behavior, particularly in different environments. To screen morphology in a high-throughput manner, we developed an automatic image classifier specifically designed to assign conidiophore phenotype. After conducting crosses, this tool was used to classify progeny conidiophores to fit a genetic model for heritability. Lastly, we performed RNA-Sequencing to identify genes differentially expressed in the mycelia and conidiophores of strains representing each conidiophore phenotype, finding that the Bulky strain exhibits a unique transcriptional profile from that of WT and Wrap. Together, this work lends novel insight to phenotypic variation of the conidiophore and its robustness to environmental perturbations, as well as genetic differences underlying this variation in a natural population.