Bringing spontaneous plants to cultivation: issues and constraints for medicinal and aromatic plants

In many places on Earth, MAPs have been representing for centuries the basic sources for food and medicines for local populations. In their traditional utilization form, they were collected from the wild, a sustainable practice only until it is not too massive. Many studies demonstrate that when the needs from market and industry overpass a definite threshold, only specialized cultivation can guarantee high-quality and abundant quantities of plant biomass to address to industrial purposes. However, large sections of public and buyers are deeply convinced that herbal products keep their maximum activity level only when collected from the wild, as the wild product holds a “naturality” feature that is often not perceived when the same product is obtained by cultivation. As a matter of fact, there is no actual reason to believe that a cultivated plant could gain a lower quantity or quality of active principles with respect to wild plants. Examples from Hypericum perforatum and H. perfoliatum, as well as Thymus spinulosus and T. longicaulis, confirm that in these species no significant decrease occurs in the most representative phytochemicals detected, after the shifting from wild to cultivated. It is true, instead, that a finely tuned cropping technique can in some case enhance the level of some metabolites of interest. However, many issues arise in this transition, mostly due to several morphological and biological features of MAPs that can represent significant constraints to an efficient large- and medium-scale cultivation, such as (i) the shattering of fruits/seeds, (ii) the simultaneous presence of reproductive parts at different development stages, and (iii) a non-optimal reaction to the major agronomic inputs (i.e. irrigation or fertilization) that often induces an unwelcome production of plant biomass rather than seeds (as often recorded in many Apiaceae, e.g., coriander or fennel).