Development of Molecular Tools to Identify the Avocado (Persea americana) West-Indian Horticultural Race and Its Hybrids

Avocado (<i>Persea americana</i> Mill.) is cultivated in a wide range of environments, from tropical and semitropical to subtropical regions. Its fruit, of high nutritional value, is increasingly demanded worldwide. Spain is the main European producer, but avocado cultivation in certain areas, such as the Canary Islands, requires the genetic identification of <i>West-Indian</i> rootstocks because they often show tolerance to low-quality water and soil salinization. In the present study, eight novel Retrotransposon-Based Insertion Polymorphism assays, derived from previously characterized inter-Primer Binding Site markers, have been developed and evaluated by multiplex PCR across 58 <i>P. americana</i> cultivars. The results showed 100% specificity and sensitivity in detecting the <i>West-Indian</i> genomic component, both in pure and hybrid avocado cultivars. This cost-effective and fast molecular tool provides a valuable resource for characterization and selection programs of avocado cultivars genetically related to the <i>West-Indian</i> horticultural race.