Algerian Annals of Agronomy
Volume 32, Numéro 1, Pages 11-21
2018-12-15

Morphological And Molecular Identification Of Some Algerian Trichoderma Isolates

Authors : Boureghda Houda . Bouznad Zouaouia .

Abstract

Eighteen Trichoderma isolates with high potential antagonist against phytopathogenic fungi were obtained from soil, chickpea rhizosphere and seed. Based on morphological character, two groups were distinguished among the eighteen Trichoderma isolates obtained. The first group consisted on 10 isolates (T1, T2, T4, T5, T8, T9, T10, T11, T14 and T17), of which the conidiophore morphology, as well as the branches and the phialides morphology corresponds to the Longibrachiatum section. These isolates exhibited a morphological variability, which made species identification very difficult. While, the second group (8 isolates) consisted on isolates with inflated phialides disposed in pairs or in verticils such as Pachybasum section. The second group isolates presented globular conidia, and based on conidia sizes this group was subdivided in two subgroups. The first one included the isolates: T6, T12, T15, T16, and T18 while the second one included the isolates: T3, T7, and T13. The first subgroup isolates have conidiophore with short branches such as Pachybasum section, while the second ones show long branches. Phylogenetic analysis based on ITS clustered the eighteen Trichoderma strains on two branches and three groups. The first group includes the ten Longibrachiatum section isolates which clustered with reference strains of T. longibrachiatum species. The second contains the 5 isolates T6, T12, T15, T16 and T18 with reference strains of T. harzianum and its teleomorph H. lixii. The third one grouped isolates T3, T7 and T13, reference strains of T. atroviride and its teleomorph Hypocrea atroviridis. Species determination based on classical approaches has shown that morphological criteria are not enough to determine species identity

Keywords

Morphological characteristics PCR ITS region molecular phylogeny