Triallate absorption and metabolism in relationship to tolerance in wheat (Triticum aestivum and Triticum durum)

Research was conducted to determine the influence of temperature on triallate absorption and metabolism in triallate-tolerant durum wheat (Triticum durum L. 'Monroe'), moderately tolerant Hard Red Spring (HRS) wheat (Triticum aestivum L. 'Coteau'), and susceptible HRS wheat, Alex. Uptake of 14 C-triallate by the shoot was greater at 24 than at 8 °C by all species. Triallate uptake as influenced by soil temperature is a factor affecting triallate phytotoxicity to wheat. However, Monroe shoot meristematic tissue contained more 14 C-label than Alex or Coteau, indicating that 14 C-label content in the meristematic tissue was not related to triallate tolerance. Further, the coleoptile tissue of Monroe contained less 14 C-label than Alex or Coteau. The coleoptile tissue did not prevent 14 C-label entry into shoot tissue. Coleoptile tissue did not seem to be a factor influencing triallate tolerance. 14 C-triallate concentration in the shoot related to triallate tolerance at both 8 and 24 °C. Triallate metabolism was apparently involved in differential tolerance among cultivars as the more tolerant Monroe and Coteau had more 14 C-metabolites than susceptible Alex. Key words: Wheat, triallate, herbicide, temperature, absorption, metabolism