Genetic difference analysis of Humulus lupulus L. (Hop) cultivars grown in Pazaryeri (Bilecik) using the ISSR PCR method

Abstract

Humulus lupulus L. (hop) is an important industrial plant grown only in the Bilecik-Pazaryeri district in Turkey. The most common usage area is the beer industry. It is preferred as a flavour and aroma raw material because it contains secondary metabolites. Different H. lupulus varieties are cultivated in the villages in Pazaryeri. Besides the registered varieties used by farmers, it is seen that some farmers also prefer unknown H. lupulus seeds in production. This study aimed to determine the genetic diversity of 18 H. lupulus varieties and samples cultivated in different locations for the beer industry in Pazaryeri using the ISSR (inter simple sequence repeat)-PCR method. DNA isolations were performed using a commercial kit from plant leaves grounded in liquid nitrogen. 25 ISSR primers were tested for DNA amplifications and 10 primers that produced reproducible DNA fragments were used for genetic diversity analysis. PIC (polymorphism information content) value and PCoA (principal coordinate analysis) were calculated for each primer. DNA bands obtained from PCR products electrophoresed in agarose gel were photographed. Band profiles were compared using the Phoretix1DPro program and binary data analysis was performed as present (1) / absent (0). Jaccard similarity and distance matrixes were created with UPGMA (unweighted pair group method with arithmetic mean) and a dendrogram showing genetic diversity was drawn using the MEGA 11 software. It was determined that different H. lupulus varieties grown in the same locations show location-dependent (together) branching in the dendrogram. While it is expected that registered varieties have separate branching from each other in the dendrogram, it was seen that different H. lupulus varieties grown in the same locations show location-dependent (together) branching.