Amplified Fragment Length Polymerase-Based Phylogenetic Relationships of Heirloom Tomato and Dark Green Vegetable Accessions

Abstract

Dark green vegetables such as broccoli, lettuce, and spinach are documented for their nutritional importance. Similarly, heirloom varieties also have value-added traits such as the attractiveness of fruits, limited availability, unique flavor, or other characters not found in commercial types. Since heirloom tomato varieties may require a little more care during production or handling, compared to commercial hybrids, producers can obtain a higher price when appropriately marketed. In this report, six heirloom tomato (Lycopersicon esculentum) varieties as well as four varieties of broccoli (Brassica oleracea), three varieties of lettuce (Lactuca sativa), and two varieties of spinach (Spinacia oleracea) were selected for comparative DNA fingerprinting. On quality DNAs from the leaf tissues of these vegetables, amplified fragment length polymorphism (AFLP) analyses were performed with 64 different primer pair combinations. The AFLP primer pairs, that produce ample polymorphic markers and provided desirable polymorphisms, were identified for further analyses. AFLP-generated DNA fragments were then separated by sequencing gel electrophoresis using an automated DNA analyzer (4300S NEN DNA Analyzer and Sequencer, Li-Cor Inc., Lincoln, NE, USA) through Saga™ Generation 2- AFLP® Analysis (Li-Cor Inc.) software. AFLP profiles were analyzed to generate binary code (0/1) reports on markers’ data, and then TreeCon-Dendrogram (Scanalytics Inc., Fairfax, VA, USA) software was used to deduce genetic relationships between accessions of selected vegetables. Although each accession had a distinctive DNA fingerprint, correlations between structurally similar plants and their DNA profiles were apparent enabling true to type identification and marker-assisted breeding programs.