Selection and characterization of Argentine isolates of Trichoderma harzianum for effective biocontrol of Septoria leaf blotch of wheat

Abstract

Species of the genus Trichoderma are economically important as biocontrol agents, serving as a potential alternative to chemical control. The applicability of Trichoderma isolates to different ecozones will depend on the behavior of the strains selected from each zone. The present study was undertaken to isolate biocontrol populations of Trichoderma spp. from the Argentine wheat regions and to select and characterize the best strains of Trichoderma harzianum by means of molecular techniques. A total of 84 out of the 240 strains of Trichoderma were able to reduce the disease severity of the leaf blotch of wheat. Thirty-seven strains were selected for the reduction equal to or greater than 50% of the severity, compared with the control. The percentage values of reduction of the pycnidial coverage ranged between 45 and 80%. The same last strains were confirmed as T. harzianum by polymerase chain reaction amplification of internal transcribed spacers, followed by sequencing. Inter-simple sequence repeat was used to examine the genetic variability among isolates. This resulted in a total of 132 bands. Further numerical analysis revealed 19 haplotypes, grouped in three clusters (I, II, III). Shared strains, with different geographical origins and isolated in different years, were observed within each cluster. The origin of the isolates and the genetic group were partially related. All isolates from Paraná were in cluster I, all isolates from Lobería were in cluster II, and all isolates from Pergamino and Santa Fe were in cluster III. Our results suggest that the 37 native strains of T. harzianum are important in biocontrol programs and could be advantageous for the preparation of biopesticides adapted to the agroecological conditions of wheat culture.

Trichoderma as an efficacious bioagent for combating biotic and abiotic stresses of wheat-A review

“…Trichoderma harzianum isolates T4 and T2 showed the greatest effectiveness for controlling disease, with similar reduction values to that shown by the fungicide (Folicur) application treatment (Perello et al, 2009). Stocco et al (2016) characterized 240 isolates of Trichoderma harzianum from the Argentine wheat regions by means of molecular techniques and selected 37 strains which reduced the severity of Septoria leaf blotch 50%. These 37 native strains of T. harzianum are important in biocontrol programs and could be advantageous for the preparation of biopesticides adapted to the agroecological conditions of wheat culture.…”

Biological Management of Basal Rot of Onion by Trichoderma harzianum and Withania somnifera

“…Application of culture filtrates and spore suspension of T. harzianum reduced the size of necrotic spots of black scorch disease of date palm caused by Ceratocystis radicicola (Al-Naemi et al, 2016). T. harzianum is also known to reduce severity of leaf blotch of wheat caused by Zymoseptoria tritici (Stocco et al, 2016). The modes of action of Trichoderma are competition, antagonism and production of certain antifungal compounds (Nederhoff, 2001).…”

“…Management of plant pathogens by biological means is considered an alternative environment friendly strategy for sustainable agriculture (Al-Naemi et al, 2016;Youssef et al, 2016). Trichoderma is among the most commonly used biocontrol agents and is an effective antagonist against plant pathogenic fungi ( Kumar and Mukerji, 1996;Stocco et al, 2016). Recent studies have shown that Trichoderma spp., especially T. harzianum, can control diseases caused by Rhizoctonia solani, Macrophomina phaseolina and Ceratocystis radicicola (Al-Naemi et al, 2016;Javaid et al, 2017b;Youssef et al, 2016).…”

Selección y caracterización de microorganismos con capacidad antifúngica y fertilizante aislados de la rizosfera de plantas de yerba mate de la provincia de Misiones para su aplicación como promotores del crecimiento vegetal

“…• disminución de la severidad de la mancha de la hoja en trigo causada por Zymoseptoria tritici (Stocco et al, 2016).…”

“…Las múltiples funciones de Trichoderma en las asociaciones planta-Trichoderma son de particular importancia para la sustentabilidad de los ecosistemas tanto naturales como agrícolas. La aplicabilidad de los aislamientos de Trichoderma a diferentes ecozonas depende del comportamiento de las especies seleccionadas en cada una de ellas y, como ya se ha mencionado durante este trabajo de tesis, los mejores aislamientos podrían seleccionarse de áreas de la planta y del suelo donde se espera que funcionen mejor como PGPM y donde crezcan en condiciones ecológicas similares a las que se encuentran en forma natural (Stocco et al, 2016). Diferentes especies de Trichoderma pueden exhibir variación en la actividad como PGPM, lo que hace que un estudio específico de su biodiversidad sea esencial para aprovechar al máximo el potencial de estos microorganismos (Hoyos-Carvajal & Bissett, 103 2011).…”