Resumen
Wheat stripe rust (WSR) caused by Puccinia striiformis F. tritici Erikss. (Pst) is one of the serious diseases that affect wheat planting areas around the world. Many efforts have been made to control such a serious disease including using fungicides and breeding highly resistant genotypes. However, due to Pst?s ability to produce new races that overcome these fungicides and break the resistance in the highly resistant genotypes, looking for other effective ways to restrict this disease is urgently required. One of the highly effective ways of controlling crop diseases is using biological control. In this study, the efficiency of three different Trichoderma species (Trichoderma asperellum T34, Trichoderma harzianum (TH), and Trichoderma verdinium (TV)) was tested in a set of 34 wheat genotypes at the seedling stage. The evaluation was conducted in two experiments with two different temperature regimes. In each experiment, four treatments were applied, namely, control, T34, TV, and TH. High genetic variation was found among all genotypes in each experiment and under each Trichoderma treatment. Notably, the symptoms of WSR were affected by temperature under all treatments except T34, which had a stable performance in the two experiments. The 34 studied genotypes were highly diverse, related to ten different countries, and consisted of durum and bread wheat. Out of the three studied Trichoderma species, T34 was able to improve WSR resistance in all the studied genotypes suggesting its effectiveness in inducing the resistance and producing a priming response in different wheat genetic backgrounds. The results of this study provided very useful information on the effectiveness of Trichoderma spp. in controlling WSR.