Abstract
This study examined extent of hyphal growth of Gaeumannomyces graminis var. tritici (Ggt) in seminal roots of wheat seedlings grown from seed of varying weight (12-60 mg). Hyphal invasion, measured microscopically in the inner cortex, endodermis and stele of root sections and in the early formation of stelar lesions, was found to be influenced in a complex manner by weight of seed. As weight of seed was increased, invasion of the inner cortex decreased linearly while invasion of stelar tissue varied in a non linear manner. These findings show that weight of seed must be considered when comparing levels of infection in seedlings of different cultivars of wheat.