Fusion of two compatible hyphae in Zygomycota produces
Compatible mating types in heterothallic Zygomycota sense each other via trisporic acid pheromones inducing progametangial hyphal tips to meet and swell. Contact triggers septation to form progametangia, walls dissolve at contact point, plasmogamy merges cytoplasm containing haploid nuclei. Nuclei pair then karyogamy produces diploid zygote enlarging into thick-walled zygospore surrounded by zygosporangium exhibiting warty ornamentation. Conidia and sporangiospores asexual mitospores, ascospores belong to ascomycetes. This conjugation process names conjugation fungi, essential for genetic recombination and dormancy surviving unfavorable conditions before meiospore formation inside germ sporangium after meiosis.
Ref: Campbell Biology 12th ed., Chapter 31: Zygomycota Conjugation Zygospore Formation; NCERT Class 11 Phycomycetes Fusion; NCBI Mating Mucorales