Field survey of Glycyrrhiza plants in Central Asia (1). Characterization of G. uralensis, G. glabra and the putative intermediate collected in Kazakhstan.

The characteristics of Glycyrrhiza plants from 12 collection sites in southeastern Kazakhstan were investigated. G. uralensis was observed at 9 of the sites from Almaty to Shu, and G. glabra was observed at 8 sites. At 4 sites near Shu, and 1 site near Almaty, G. glabra and G. uralensis grew together forming a mixed population, and intermediate-type plants between them were also observed at 3 sites. Although two nucleotide substitutions of the chloroplast rbcL gene were observed between G. uralensis and G. glabra, rbcL sequences of the intermediate-types were divided into G. uralensis-type (G-A type) and G. glabra-type (A-T type). HPLC analysis of the roots indicated that species-specific flavonoids, glabridin and glycycoumarin, were detected in the roots of G. glabra and G. uralensis, respectively, but neither flavonoid was detected in underground parts of the intermediate-types. HPLC analysis of their leaves indicated a significant difference among G. uralensis, G. glabra and the intermediate-type plants. Both G. glabra-specific and G. uralensis-specific compounds were detected in the leaves of the intermediate-type, thus suggesting that the intermediate plants are hybrids of G. glabra and G. uralensis.