A Simple Formula of the Endophytic Trichoderma viride, a Case Study for the Management of Rhizoctonia solani on the Common Bean

Abstract

The utilization of beneficial endophytic microorganisms presents a promising and innovative strategy for attaining environmental sustainability and fostering development. The majority of microbial bioagents are unsuitable for preparation in a suitable granular formula, and few are prepared in complicated formulas. In this work, Trichoderma viride was simply prepared in a marketable granular formula to manage Rhizoctonia solani and improve common bean growth. The GC-MS analysis showed several antimicrobial compounds in the fungal filtrate. T. viride was able to suppress the phytopathogenic R. solani in the laboratory. The formula had up to 6 months of shelf-life viability. Under greenhouse conditions, the formula improved plant resistance against R. solani. Moreover, the vegetative plant growth and physiological performance (peroxidase, polyphenol, total phenols, phenylalanine ammonia-lyase, and photosynthetic pigments) of the common bean showed obvious promotion. The formula reduced the disease incidence by 82.68% and increased the yield by 69.28%. This work may be considered a step in the right direction for producing simple bioactive products on a large scale. Moreover, the study's findings suggest that this method can be considered a novel approach to enhancing plant growth and protection, in addition to reducing costs, improving handling and application, and maintaining fungal viability for enhancing plant growth and protecting against fungal infections.

Keywords: GC-MS analysis; bioagent; growth; marketable formula; molecular identification; physiological features; simple formula; yield.

Figure 1

Phylogenetic tree constructed using partial sequences of the ITS, showing the location of T. viride AKW (MW041259) and R. solani (OQ119628), represented by a red dot, in relation to other related sequences attained from GenBank.

Figure 2

GC-MS chromatogram of bioactive metabolites of T. viride.

Figure 3

The antagonistic ability of T. viride AKW on R. solani. The radius of R. solani mycelium after 8 days of incubation in the control plate (A), the radius growth of T. viride (B), and the radius of R. solani and T. viride, showing that the bioagent covers the pathogen colony after 8 days of inoculation in dual culture plates (C).

Figure 4

The growth of T. viride on Petri plates (A) and its granulated formula (B).

Figure 5

Influence of the tested GBTF treatment on the progress of disease severity, and incidence of Rhizoctonia solani infection of common bean under greenhouse conditions. Tukey’s test was conducted with a significance level of 0.05; the columns (means ± SD) that have a diverse letter within a parameter are considered significantly different. P; R. solani pathogen only, PGBF; P + PGBF, and PF; P + Rhizolex T50, NC; the negative control (no treatment), GBEF; the sole GBEF formula without infection, and F; the recommended fungicide without infection (15 pots/treatment).

Figure 6

Growth and yield of common bean as affected by GBEF treatment under greenhouse conditions. Tukey’s test was conducted with a significance level of 0.05; the columns (means ± SD) that have diverse letter(s) for each criterion are considered significantly different. P; R. solani pathogen only, PGBF; P + PGBF, and PF; P + Rhizolex T50, NC; the negative control (no treatment), GBEF; the sole GBEF formula without infection, and F; the recommended fungicide without infection (n = 15 plant/treatment).

Figure 7

Influence of GBTF treatment on common bean growth under greenhouse conditions: (1) R. solani pathogen (P), (2) P + GBTF, (3) P + the fungicide (F), (4) control without any treatment, (5) the single GBTF formula without infection, and (6) the single F without infection.