Detection of Fusarium contamination of cotton seeds using morphological traits and molecular markers

In order to investigate the contamination of cotton seeds with Fusarium fungi, samples of different classes of 10 cotton cultivars were obtained from Southern Khorasan, Razavi, Golestan and Fars provinces. Various sections of a seed such as full seed, coat, kernel (endosperm and embryo), endosperm and embryo were cultured on the nutrient medium of potato dextrose agar and water agar. Of the 23 cotton seed samples, 76 isolates of Fusarium was obtained. The contamination in fuzzy and delinted seeds were 98.7 and 1.3 percent respectively. The hightest percentage of purified Fusarium was from kernel. Identification based on morphological traits showed that the isolates with the frequency of 39, 23, 10, 2, 1 and 1 isolates belonging to the species Fusarium equiseti, F. proliferatum, F. semitectum, F. compactum, F. nygamai and F. solani. Species of F. compactum and F. nygamai are reported for the first time from Iran. The application of Polymerase chain reaction and the use of specific primers of F. equiseti and F. proliferatum dominant species have led to the production of proprietary DNA bands using the DNA of the relevant fungal species, as well as the seed DNA that naturally contaminated these species. In this way, the results of identification of these two species based on morphological traits were confirmed by the molecular method. This study revealed that Fusarium traces are detected in infected seeds using the PCR reaction.