Genetic relatedness among Aechmea species and hybrids inferred from AFLP markers and pedigree data

Bromeliads are among the most economically important potted ornamentals, however little is available about genetic variability among bromeliad cultivars or hybrids for breeding purposes. In this study, genetic relatedness among cultivars and selected hybrids of Aechmea bromeliad was investigated using amplified fragment length polymorphism (AFLP) markers and pedigree data. Eight AFLP primer combinations produced 1498 DNA fragments, of which 1465 (97.8%) were polymorphic. The AFLP-based genetic similarity ranged from 0.20 to 0.61 and averaged 0.33, while the corresponding pedigree-based coefficient of coancestry varied from 0 to 0.5, with an average of 0.07. This reveals large variability and genetic diversity among the investigated Aechmea bromeliads. The AFLP-based cluster analysis grouped the Aechmea bromeliads well according to their breeding years and ancestors, whereas pedigree-based cluster analysis divided the Aechmea bromeliads corresponding only to their ancestors. Additionally, the AFLP-based genetic similarity followed a normal distribution, while pedigree-based coefficient of coancestry displayed a skewed distribution. A significant though moderate correlation (r = 0.35, P < 0.001) and a significant linear relationship with low coefficient of determination (R2 = 0.12) were observed between the two measures. This indicates that AFLP is more effective in quantifying genetic relatedness among Aechmea bromeliads. The present study provides useful implications for the efficient conservation and utilization of bromeliad germplasm.