3.4 | FISH and GISH analysis
To further explore the genomic constitutions of natural hybrids, we selected some hybrids for in situ hybridization. St2-80 was a FISH marker for the St genome (Wang, et al., 2017). Signals produced by St2-80 were present on the entire arm of the St genome chromosomes, except at the centromeric region and near centromeric region (Wang et al., 2017). This marker was used to detect if the St genome presented in the putative parents and hybrids.
FISH results showed that 14 chromosomes of putative parents and hybrids displayed fluorescent signals indicating that they contained one set of St genome (Figures 6a, c, e and 7a, c, e). This result was confirmed by GISH analysis, where 28 chromosomes of putative parents and hybrids were hybridized with theStY probe from R. ciliaris (Figures 6b, d, f and 7b, d, f). The results of FISH and GISH indicated that the genomic constitution of putative parents and 11 hybrids (RH1-3, RH1-8, RH1-11, RH1-14, RH2-2, RH2-10, RH2-12, RH2-15, RH2-17, RH2-37, RH2-39) were StY .