MOLECULAR-CLONING OF PHENYLALANINE AMMONIA-LYASE CDNA AND CLASSIFICATION OF VARIETIES AND CULTIVARS OF TEA PLANTS (CAMELLIA-SINENSIS) USINGTHE TEA PAL CDNA PROBE

Tea (Camellia sinensis) phenylalanine ammonia-lyase (PAL) cDNA was clo ned using labelled rice PAL cDNA as a probe. The PAL genes of the tea plant were investigated by restriction fragment length polymorphism (R FLP) analysis using tea PAL cDNA. PAL genetic variation in tea plants was much larger than predicted due to the presence of various hybridiz ed fragments in the Assam hybrids, which are hybrids between C. sinens is var 'assamica' and var 'sinensis'. On the other hand, hybridized ba nd patterns of Japanese green tea cultivars belonging to var 'sinensis ' could be divided into five groups. Furthermore, a short-length PAL p robe, about 280 bp including the 3' untranslated sequence, detected 3 DNA fragments of different lengths, which were named A, B and D. An ex periment tracing the PAL gene heredity showed that A, B and D fragment s were inherited according to the Mendelian monogenic ratio. Therefore , PAL genes identifiable by A, B and D fragments are multiple alleles, and the PAL gene is present as a single gene in the tea haploid genom e. It was also clear that five groups of Japanese green tea cultivars were characterized by the composition of these PAL fragments. From RFL P analysis using tea PAL cDNA, we succeeded in distinguishing Assam hy brids and Japanese green tea cultivars with high and low catechin cont ent, respectively, and in grouping Japanese green tea at the cultivar level.