VIEW ARTICLE

Differentiation of Transmission and Incubation Temperatures for Wheat Spindle Streak Mosaic Virus. J. T. Slykhuis, Research Scientist, Research Station, Research Branch, Agriculture Canada, Ottawa, Ontario K1A 0C6; Phytopathology 64:554-557. Accepted for publication 2 November 1973. DOI: 10.1094/Phyto-64-554.

The optimum and maximum constant temp for the development of wheat spindle streak mosaic on wheat (Triticum aestivum) were 10 C and 17 C if the plants were inoculated manually, and 8 C and 15 C if the plants were grown in infectious soil. More plants developed symptoms from soil-borne infection at temp that fluctuated between 5 C and 17 C than at any constant temp. Differences in temp requirements for infection from soil and for the development of symptoms were found by growing seedlings in infectious soil for periods up to 4 wk, then removing, washing the roots free from soil, and replanting them in noninfectious soil before subjecting them to specific incubation temp. The optimum and maximum temp for infection (15 C and 20 C) were each 5 C higher than for incubation after infection. In some tests, all wheat plants developed spindle streak mosaic if they were grown in infectious soil at 15 C for 4 wk then transplanted to noninfectious soil and kept at 10 C for 8-10 wk.