학술논문
Efecto de Trichoderma asperellum cepa T34 y compost en plantas de tomate frente estrés biótico
Document Type
Dissertation/Thesis
Author
Source
TDX (Tesis Doctorals en Xarxa)
Subject
Language
Spanish; Castilian
Abstract
This thesis consists of 3 chapters. In Chapter I, we evaluated the induction of resistance in tomato plants grown in olive marc compost (OMC) compared to perlite, inoculated or not with Trichoderma asperellum strain T34 (T34). OMC induced the greatest control of Botrytis cinerea leaf infection (60%); followed by perlite inoculated with T34 (35%), being perlite a disease conductive substrate. The SA / ABA route was involved in the induction of systemic resistance by OMC but not by T34. OMC and perlite inoculated with T34 used as growth media increased plants growth. Some physiological parameters showed that plants grown in OMC were close to stress, suggesting a eustress situation. In Chapter II, we evaluated tomato plants root exudates and their relation with the induction of resistance in perlite inoculated with T34 against B. cinerea. Tomato plants infected with B. cinerea in leaves induced changes in the secretion pattern of root exudates, increasing gluconic acid levels and decreasing sucrose and inositol levels. T34 induced systemic resistance and reduced disease severity. Tomato plants infected with B. cinerea maintained T34 root populations, while T34 populations decreased in plants not inoculated with the pathogen. Gluconic acid (same concentration as in exudates) had a positive effect in the in vitro growth of T34. These results indicate the existence of leaf to root communication that also involves an increase in the populations of T34 and a reduction of disease severity. In Chapter III, we evaluated light and nutrient availability effect on the growth of tomato plants grown in perlite inoculated or not with T34, its effect in plants gene expression and its relation with growth improvement. T34 in the rhizosphere induced changes in the expression of 64 genes. The biological process terms response to stress, response to stimulus and proteolysis were enriched mong the 63 up-regulated genes. These changes promoted plants growth under favorable conditions (complete nutrient solution and 300-400 μmol m-2 s-1 PPFD), and similarly they could be related to growth promotion at low availability of nutrients (1: 3 dilution of complete nutrient solution) at both 60-80 and 300-400 μmol m -2 s -1 PPFD.