Effet de biostimulants issus de cultures cellulaires végétales sur le développement morphologique de la tomate (Solanum lycopersicum) en conditions de stress hydrique et évaluation de percolats de vermicompost

Details

Supervisors

Quinet, Muriel ; Annet, Marie

Faculty

Faculté des sciences

Degree label

Master [60] en sciences biologiques

Abstract

enEffect of biostimulants derived from plant cell cultures on the morphological development of tomato (Solanum lycopersicum) under water stress conditions and evaluation of vermicompost percolate Against the backdrop of increasing drought stress driven by climate change, biostimulants represent a sustainable alternative to conventional chemical inputs for maintaining crop productivity. This thesis evaluates the effect of two experimental biostimulants derived from plant cell cultures, identified as SL and CC, on the morphological development of tomato (Solanum lycopersicum cv. Moneymaker) subjected to controlled water deficit. A full factorial design comprising 24 treatment combinations was established across 216 plants, crossing two water regimes (100% and 30–35% of field capacity), two biostimulants applied at two concentrations in either crude or filtered form, via two application routes: foliar spraying and soil amendment. Leaf area, stem height, aerial and root dry biomass, root length and root-to-shoot allocation ratio were measured at harvest. In parallel, a vermicomposting experiment compared leachates from two feeding modalities: fresh plant material versus seven-day pre-composted material, by monitoring pH, electrical conductivity, density, and concentrations of polyphenols, flavonoids, proline and soluble sugars. Water deficit emerged as the dominant factor, causing a drastic reduction in biomass and leaf area alongside a shift in biomass allocation toward the root system. No biostimulant produced a statistically significant effect, although consistent descriptive trends favoured crude extracts over filtered ones and indicated a functional complementarity between the two application routes. Regarding vermicomposting, only electrical conductivity and density differed significantly between the two modalities, reflecting early ionic mineralisation in the pre-composted material. These findings highlight the need for protocols incorporating repeated applications, chemical characterisation of the extracts and biochemical measurements on plant tissues, while opening the way for the agronomic valorisation of vermicompost leachates as potential biostimulants within a circular economy framework.