CBL - Campus del Baix Llobregat

Projecte llegit

Títol: Capacitat de Bacillus firmus I-1582 i de Trichoderma asperellum T34 per colonitzar l¿arrel de cultius hortícoles

Estudiant que ha llegit aquest projecte:

Tutor/Cotutor: SORRIBAS ROYO, FRANCISCO JAVIER

Departament: DEAB

Títol: Capacitat de Bacillus firmus I-1582 i de Trichoderma asperellum T34 per colonitzar l¿arrel de cultius hortícoles

Data inici oferta: 07-10-2021      Data finalització oferta: 07-05-2022

Estudis d'assignació del projecte:
    GR ENG SIS BIOLÒGICS

Lloc de realització:
EEABB

Segon tutor extern: Aïda Magdalena Fullana

Paraules clau:
Cucurbitàcies, solanàcies, qPCR, M. incognita, Trichoderma asperellum, Bacillus firmus

Descripció del contingut i pla d'activitats:
Bacillus firmus I-1582 i Trichoderma asperellum T34 han estat
citats com a promotors del creixement de plantes i com
antagonistes de nematodes fitoparàsits per la capacitat
d'induir mecanismes de defensa de la planta, encara que és
dependent de l'espècie vegetal. La resiliència d¿aquests
microorganismes un cop aplicat podria dependre de la capacitat
de colonitzar les arrels de les plantes, mantenint o
incrementant la seva densitat al sòl i contribuir a mantenir un
estat saludable de la planta i la tolerància envers factors
biòtics i abiòtics. L¿objectiu general del treball és el
conèixer la capacitat de colonitzar les arrels de cultius
econòmicament importants de cucurbitàcies i de solanàcies per
aquests microorganismes, a fi d¿incrementar l¿estat del
coneixement de la interacció planta-microorganisme que es
produeix.

Overview (resum en anglès): Plant parasitic nematodes are invertebrates that have adapted to almost every ecological niche and are vastly distributed in all the natural and cultivated soils around the world. The infection of crops caused by this parasite causes both direct diseases such as galls on roots, necrosis and deformities on the stem and indirect diseases due to the interaction with other phytopathogen organisms that cause severe reductions in the crop¿s yields. Traditionally we have flighted nematode infections using chemical nematicides but due to the current trend on its reduction, the necessity for alternative sustainable tools for pest control has increased.
One alternative is the use of biological agents such as fungus or bacteria capable of directly affect the nematode populations and/or inducing nematode resistance to the plant in order to reduce the nematode population density under a certain economic loss threshold.
In this final degree project, we will study the ability of the fungus Trichoderma asperellum soca T34 (T34) and the bacteria Bacillus firmus soca I1582 (BF) to induce resistance towards the nematode Meloidogyne incognita in the following crops: watermelon, melon, pepper, tomato and eggplant.
Tests were carried out in turrets with a capacity of 200 cm3 containing sterile sand, in order to determine the effect of applying 2·106 UFC de T34 o 109 UFC de BF, one week after transplanting the crops, to the populations of M. incognita inoculated with 200 second-stage juveniles per plant one week after applying the microorganisms. An untreated control group was included for comparison. The plants were kept in a climate chamber at 25 ºC long enough for the nematode to complete its life cycle. Nematode infectivity, reproduction, and fertility were determined at the end of the trials and each crop was statistically compared to determine possible resistance induction by the microorganisms. Likewise, root colonization by both microorganisms was determined using PCR and qPCR and correlated with nematological results.
These results were correlated with a quantitative analysis of the amount of Trichoderma asperellum or Bacillus firmus found on the plants roots to corroborate whether the suppressive effect was caused by the presence of said microorganisms and evaluate the capacity of both microorganisms to colonize the roots of the studied crops. Bacillus firmus I-1582 has shown capable of colonizing the roots and inducing resistance against M. incognita when added to tomato cv. Durinta and watermelon cv. Sugar Baby plants but not when added to eggplant cv. Cristal. Trichoderma asperellum has shown capable of colonizing the roots of tomato cv. Durinta and watermelon cv. Sugar Baby but has only induced resistance against M. incognita when added to tomato plants.
No significant correlation has been observed between the colonization capacity of the microorganisms and its effect on the nematode population.
The melon crop was excluded from the trials due to an insufficient number of viable control samples. Pepper plants were not infected by M. incognita in these trials and were also excluded.


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