The influence of clonal micropropagation on productivity and differentiation of Mentha pіperіta plant tissues

Abstract

Peppermint grass, as a raw medicinal plant material, has great importance for the pharmaceutical industry. The influence of clonal micropropagation and chemotherapy has been established in vitro on six breeds of Ukrainian selection peppermint plants, in particular on the sprouts’ conductive system structure and tissue development, general biomass accumulation, and in vivo productivity of breeds. The influence of clonal micropropagation and chemotherapy on important productivity indices of the plants has been established in vitro in six breeds of Ukrainian selection peppermint plants as pharmacopeial plants. The linear meter method, the microscopic method, the standard histochemical methods, and the statistical analysis method were used in the studies. A clear tendency to increase in the leaf cover, air-dry leafage and rhizome was observed in breeds of Ukrainian selection peppermint to which propagation and in vitro improvement technology was applied. The air-dry leafage yield significantly increased after in vitro culture from 7.6% in the Lidiia breed to 51.4% in the Chornolysta breed recognized as a state mint standard in Ukraine. The leaf cover increased from 8% to 21% in peppermint plants improved in іn vitro culture. This method promoted essential oil quantity increase from 9.8 to 28.6 kg per hectare. The rhizome yield increased by 6.3–40.4% in all peppermint plants breeds after improvement in in vitro culture on average within one vegetation year. The Lebedyna Pisnіa and Mama breeds were characterised by the most intensive development of all investigated anatomic and morphological indices after in vitro culture: rhizomes yield increased by 40.4% and 40.1%, air-dry leafage by 37.1% and 26.6%, leaf cover by 21.0% and 13.0%, and essential oil quantity per hectare increased by 38.1% and 28.5% accordingly. Anatomical and histochemical studies of sprouts of Ukrainian selection peppermint plants breeds confirmed increase in xylogenesis intensity in the majority of the studied breeds (except Lidiia and Ukrains’ka Pertseva) after in vitro culture improvement. The xylogenesis process was most expressed in the Mama and Chornolysta breeds. Air-dry leafage, rhizome yield, and leaf cover increased in all peppermint plants breeds after in vitro improvement, which could be critical for the pharmaceutical industry.