Genotype identification through molecular reconstruction of an old pedigree of diploid and triploid Hydrangea macrophylla lacecap cultivars

P. Hempel, A. Hohe, C. Tränkner
We genotyped a Hydrangea macrophylla collection including 120 plants. These plants represented 43 cultivars that were developed between 1909 and 1987. These plants were genotyped with 12 SSR markers and 2 to 7 alleles were detected per marker. Surprisingly, we identified 62 instead of 43 distinct fingerprints, because 2 to 4 different genotypes were determined in 25 out of 43 cultivars. Frequently, these genotypes resembled each other very much in phenotype, suggesting a mix-up of genotypes under the label of one cultivar. However, also plants with lacecap and mophead inflorescences as well as diploid and triploid plants were wrongly grouped together. In order to determine cultivar-specific fingerprints, we reconstructed the “Wädenswil” pedigree at molecular level. Based on this pedigree, which encompasses 32 cultivars, we predicted cultivar-specific fingerprints and identified at least 20 “Wädenswil” cultivars by fingerprint (Hempel et al., 2018). Based on the 2C DNA content of these plants, we detected 4 putative interploid crosses between diploid and triploid plants. These interploid crosses resulted in diploid or/and triploid offspring, confirming that crosses with triploids were successfully performed in the “Wädenswil” breeding program. Here we present exemplarily the possibilities and limitations to predict cultivar-specific fingerprints.
Hempel, P., Hohe, A. and Tränkner, C. (2020). Genotype identification through molecular reconstruction of an old pedigree of diploid and triploid Hydrangea macrophylla lacecap cultivars. Acta Hortic. 1283, 65-70
DOI: 10.17660/ActaHortic.2020.1283.10
https://doi.org/10.17660/ActaHortic.2020.1283.10
microsatellite, SSR, fingerprint, vegetatively propagated crop, genotype identification
English

Acta Horticulturae