In vitro and In vivo Efficiency of Trichoderma harzianum against Phoma and Glocladium Soft Rot Occurred on Tomato Fruits (Lycopersicon esculentum)

Abstract

The present investigation aims to evaluate the in vitro and in vivo ability of T.harzianum to control the Phoma and Glocladium soft rot, that occurred on tomato fruits (Lycopersicon esculentum). Phoma sp. and Glocladium sp. were isolated from infected tomato fruits, which were brought from Oum-elbouaghi market, and identified in laboratory of microbiology, university of Oum-elbouaghi (Algeria).One isolate of T.harzianum / Hypocrea lixii was brought from the same laboratory. The results of direct confrontation (in vitro) of T.harzianum against Phoma sp. and Glocladium sp. on PDA medium, showed that a different inhibition in the mycelia growth of the tested fungus. That inhibition was equal in the fourth day of the experiment to 39.58 % and 25.92% in Phoma sp. and in Glocladium sp. respectively. The microscopic observations of mycelia showed that the mycelia of T.harzianum was capable of overgrowing and degrading mycelia and chlamydospores of Phoma sp., coiled around the mycelia of Phoma sp. and Glocladium sp. However, it did not show any growth of the tested fungus when re-planting a disk from the interaction hyphal area between T.harzianum and Phoma sp. or Glocladium sp. from dual cultures, while T.harzianum grew alone in plates. In vivo screening and after 7 days of incubation T.harzianum showed an antagonistic activity against the tested fungus on tomato fruits, with inhibition equal 71.43% and 100%, in Phoma sp. and in Glocladium s.p respectively, compared with controls. Beside we found after cutting the superficial layer of the tested tomato fruits, that the treated fruits with T.harzianum stayed saints, compared with control, when Glocladium rot infected their deep tissues. This strain of T.harzianum may offer potential for biological control of tomato Phoma and Glocladium soft rot