Comparative genomic analysis of Korean and Japanese green tea trees by using molecular markers

Abstract

Although green tea is one of the most popular beverages in many countries, the evolutionary origin of Korean and Japanese green tea trees has not been extensively elucidated in a molecular level. Lineages of the five Korean green tea populations and cultivars growing in Hadong area were examined in comparison with the six Japanese and one Chinese cultivars using phylogenetic analysis and restriction fragment length polymorphism (RFLP) analysis with cleaved amplified polymorphic sequence (CAPS) markers. Molecular phylogenetic analyses using the non-transcribed region (NTS) region of the 5S rRNA suggested that the Korean Hadong cultivar was a minor variant of the Korean Hadong Cheon-nyeon wild tea plant, which has grown in the Hadong area more than 800 years. RFLP analysis with CAPS markers of the genes in phenylpropanoid biosynthetic pathway showed that all of the Korean Hadong wild tea populations and cultivar had unique polymorphism patterns, when compared with those of the six Japanese and one Chinese cultivars. In addition, Hadong Cheon-nyeon wild tea showed unique CAPS patterns in the phenylalanine ammonia-lyase (PAL) locus, indicating that the three CAPS markers in the PAL gene are sufficient to distinguish Hadong Cheon-nyeon wild tea from the others. Thus, our genetic analyses suggested that the Korean Hadong Cheon-nyeon wild tea plant might have evolved as a different lineage from the other wild green tea populations in the Hadong area or the Japanese tea cultivars. Key words: Restriction fragment length polymorphism, cleaved amplified polymorphic sequence marker, green tea, Hadong wild tea, evolutionary origin