Biological control of one species belonging to the dominant mycobiota of rice of Valencia

The possible biological control of the seed-associated fungus,Nigrospora oryzae byTrichoderma harzianum under different environmental conditions was investigated. A study of the fungal growth in dual cultures revealed thatT. harzianum inhibited by contactN. oryzae at all testing temperatures and water activities tested except at 0.95a w and 15 °C, whereT. harzianum inhibited pathogen growth before hyphal contact and exhibited an inhibition zone between the colonies of both fungi. Suppression of the sporulation, loss of turgor and cell collapse, wall’s disintegration, coiling and penetration ofT. harzianum around different structures ofN. oryzae were observed by cryo-scanning electron microscopy. The effect of abiotic factors water activity and temperature on fungal growth was determined.