The mycoflora of perennial ryegrass seed and their effects on the germination and seedling vigour

Twenty seed samples of perennial ryegrass Lolium perenne L. cultivars produced in different countries were analyzed to determine the species and location of seedborne fungi. Fifty-two species belonging to 36 genera were identified from seed without surface sterilization and thirty-three species belonging to 20 genera were identified from surface sterilized seeds. Most fungi were located in the endosperm followed by the pericarp and the embryo. The effects of twenty-seven seedborne fungi on the germination and seedling vigour index were also studied using the standard blotter method and the paper towel method. Seeds inoculated with Acremonium sp. showed insignificantly increase in percentage germination (P > 0.05), had significantly faster germination rates and increased shoot and root length growth and seedling vigour (P < 0.05). Cladosporium cladosporioides, C. sphaerospermum, Cylindrocarpon sp., Periconia sp. and Ulocladium sp. had no significant effect on these indexes compared to their respective control (P < 0.05). Other fungi had adverse effects on seed germination and seedling vigour (P < 0.05), especially Fusarium avenaceum, F. semitectum, F. culmorum, Marielliottia hiseptata, Bipolaris sorokiniana and Trichothechan roseum. Fusarium semitectum, M. biseptata, B. sorokiniana and T. roseum caused abnormal seedling growth and resulted in the root length, shorter than the shoot lengths.