JK100-1 and JK100-2 were two subcultures from a single basidiospore (JK100) of basidium 84. Basidiospore JK100 was completely heterozygous for all the marker loci on chromosome 1. However, analyses of the two subcultures identified that the two subcultures showed reciprocal genotypes for chromosome 1 with JK100-2 showing an identical genotype to the genotype of a different spore JK99. JK200-1 and JK200-2 were two subcultures from a single basidiospore JK200. Four recombination breakpoints were identified for chromosome 1 within this basidium and a minimum of three Chromosome 1 haploid genotypes (137-H1 to 137-H3) was inferred for this basidium to explain the observed genotypes. However, meiosis generates reciprocal recombinant genotypes. Thus, three additional Chromosome 1 genotypes are further inferred. Haploid genotypes 137-H4-cH1, 137-H5-cH2, and 137-H6-cH3 are the reciprocal genotypes for 137-H1, 137-H2, and 137-H3 genotypes respectively. Since each round of meiosis generates a maximum of four haploid nuclear genotypes, mitotic chromosomal crossing-over must be involved to produce the six haploid genotypes chromosome 1.