Abstract:
L'utilisation des agents de biocontrôle et les agents PGPR est considérée comme une solution
intéressante pour la production et la protection des cultures. Le présent travail consiste à étudier l’effet
PGPR et Biocontrol de quatre souches de streptomyces (TM52, IA1, D54, D15) sur des plants de
tomate en comparaison avec deux témoins. Des semences de tomates (Solanum lycopersicum. L. cv
Marmande) traitées avec les souches bactériennes et les témoins ont été plantées pendant 40 jours, les
paramètres suivants ont été mesurés: pourcentage de germination, la biomasse, les pigments
photosynthétiques, la perméabilité membranaire, l’accumulation des sucres totaux solubles et de la
proline, les activités catalase et peroxydase.
Les résultats statistiques obtenus ont montré l’efficacité de ces souches "D15, D54, IA1 et TM52 " en
termes de promotion de la croissance des plants de tomates dans des conditions normales et en termes
de promotion de la résistance des plants de tomates dans des conditions de stress biotique. Ces
résultats ouvrent les perspectives d’une étude de terrain visant à valider l’utilité de ces souches dans
l’amélioration de la croissance de la tomate et sa résistance aux conditions de stress biotique.
Description:
This work aimed to evaluate the PGPR and the Biocontrol effects of 4 streptomyces
strains (TM52, IA1, D15, D54) on tomato seedlings (Solanum lycopersicum. L.
cvMarmande). Two controls were used; the first was an ordinary control (non-treated seeds)
and the second control represents tomato seeds treated with a chemical fungicide “Thirame”
used to explore the effect of a chemical fungicide on seeds and in order to derive a
comparison against with what is hopefully to be biopesticide “the bacterial strains”.
The studied parameters in this work were: percentage of germination, biomass,
chlorophyll content, cell membrane permeability, accumulation of total soluble sugars and
proline and enzymatic activity.
According to the obtained statistical results, seeds treated with the bacterial strains
showed an improvement under normal conditions as well as under biotic stress conditions.
For the PGPR effect, the strains “D15, D54, TM52” showed a high productivity than
controls because they were characterized by an increase in the percentage of germinationand a
decrease in the cell membrane permeability, accumulation of total soluble sugars and proline
For the Biocontrol effect, D15, D54, and TM52 strains revealed an important
resistance towards the biotic stress because they showed an increase in the percentage of
germination and a decrease in cell membrane permeability, accumulation of proline and total
soluble sugars. In addition to that D54 and TM52 strains showed lower peroxidase activity.
In the light of the results of this modest work, we conclude that the D15, D54 and
TM52 strains are the most efficient in terms of promoting tomato plants growth in normal
conditions and in terms of promoting tomato plants resistance towards Fusarium. These
results opens up prospects for exploitation of these four strains as excellent inocula for a field
study to confirm their utility in improving tomato plants production and resistance to
Fusarium.
