Reactions of Various Cultivars of Almond to Toxin-Producing Aspergillus flavus Isolates

Samples were collected from different regions of two provinces, Markazi and Semnan, their contamination by Aspergillus flavus was examined. The results of A. flavus colony counts in different samples of almond showed that among 20 experimented samples, 11 samples were contaminated by fungus; therefore, 8 cultivars of almond, Shahroud 6, Shahroud 21, Shahroud 12, Shahroud 8, Shahroud 17, Rabie, Mengha, and Sangi Shireen, were collected in order to evaluate their sensitivity to fungal colonization and the sporulation rate of fungus on them. The results of statistical analysis showed that on the third, fifth, and seventh days, Shahroud 12 was the least resistant cultivar [average pollution (99.5%)], whereas Shahroud 6 was the most resistant [average contamination (7.36%)] at a level of 5 % for growth of A. flavus after 7 days. Experiments related to the testa of almond show that the testa can be a barrier against penetration of fungus into the inner part of the almond, decreaseing fungal growth, and thus reducing the weight of mycelium and sporulation in almonds.