Cell and tissue plant cultures are used either to save vulnerable species from extinction or to multiply valuable genotypes, or both, and are widely applied for economically important plant species. For medicinal plants, the use of in vitro technologies for the production of secondary metabolites and pathogen-free plants has been greatly developed. Two opposite aspects characterize the in vitro micropropagation of medicinal plants: maintaining genetic fidelity for the perpetuation and preservation of elites, and the identification and exploitation of somaclonal variations associated with new, useful traits. A balance between what is advantageous and what is undesirable is necessary, and this implies the identification of somaclonal variability at all levels, from the phenotypic to molecular ones. This review addresses the somaclonal variation arising from the in vitro multiplication of medicinal plants from three perspectives: cytogenetics, genetics, and epigenetics. The possible causes of the appearance of somaclones, the methods for their identification, and the extent to which they are desirable are presented comparatively for different plant species with therapeutic properties. The emphasis is on the subtle changes at the genetic and epigenetic level, as it results from the application of methods based on DNA markers.

It is well known that modern agriculture would not be able to meet the current demand for food without the help of pesticides. However, conventional pesticides have been proven to be extremely harmful to the environment, to the species they are applied to, and, ultimately, to humans. As a result, bio-pesticides have been introduced in recent years and include natural substances that control pests, such as biochemical pesticides, microorganisms used as pest control agents (microbial pesticides), and pesticide substances produced by plants containing added genetic material, known as plant-incorporated protectants (PIPs). Although these are natural products, their widespread use has led to an increased presence in the environment, raising concerns regarding their potential impact on both the environment and human health. The aim of our study was to determine the phyto- and cytogenotoxicity caused by two insecticides, both certified for use in ecological agriculture: one biochemical (BCP) and the other microbial (MP), which were applied in three concentrations (the maximum recommended concentration by the manufacturers (MRFC), 1.5X MRFC, and 2X MRFC) to the meristematic root tissues of Allium cepa. The results were compared to a negative control (tap water) and a positive control (a chemical pesticide (CP) containing mainly Deltamethrin). Phytotoxic and cytogenotoxic effects were analyzed at two time intervals (24 and 48 h) by measuring root length, growth percentage, root growth inhibition percentage (phytotoxicity tests), and micronuclei frequency and chromosome aberrations (anaphase bridges, chromosomal fragments, anaphase delays, sticky chromosomes, laggard/vagrant chromosomes) (cytogenotoxicity analyses), respectively. The tests conducted in this study showed that the microbial insecticide provides greater safety when applied, even at higher doses than those recommended by the manufacturers, compared with the biochemical insecticide, whose effects are similar to those induced by the chemical pesticide containing Deltamethrin. However, the results suggest that both insecticides have clastogenic and aneugenic effects, highlighting the need for prior testing of any type of pesticide before large-scale use, especially since the results of the A. cepa tests showed high sensitivity and good correlation when compared to other test systems, e.g., mammals.