New elements for assessing the morphogenesis of hops regenerants in vitro

Different indicators and methods for assessing microplants are used for plant culture in vitro: monitor the dynamics of development and new organs formation, use scales for visual assessment, qualitative grading scales, and scoring. The data obtained from assessing the growth characteristics of five Humulus lupulus L. genotypes revealed the correspondence of the internodes formation rate to an S-shaped, or sigmoid, curve. Based on the analysis of the morphological structures formation, the authors proposed a scale for assessing the growth parameters of Humulus lupulus L. in vitro. The authors noted significant variability in morphometric parameters depending on the maturity group of the variety. Thus, the Tsivilsky early season variety formed standard sizes of regenerants (6-7 internodes) 10 days earlier than the Taurus late season one. The following scale can be used to assess the influence of various factors on the growth and development of regenerant plants in species growing rapidly in vitro (hops, grapes, mint, etc.), and to develop clonal micropropagation programs.