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High‐Temperature Sodium Hypochlorite Effects on Viability of Tilletia Controversa Teliospores and Wheat Seed
Author(s) -
Chastain T. G.
Publication year - 1991
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci1991.0011183x003100050049x
Subject(s) - germination , biology , sodium hypochlorite , seedling , seed treatment , agronomy , cultivar , spore , horticulture , botany , chemistry , organic chemistry
Contamination of wheat ( Triticum aestivum L.) grain by Tilletia controversa Kühn teliospores is a constraint to expanding international markets for U.S. Pacific Northwest wheat. Developing a method to kill teliospores on wheat grain and seed could be very beneficial for the region's agricultural economy. This study was conducted to evaluate high‐temperature NaOCl as a disinfestant for T. controversa teliospores and to ascertain the effect of NaOCl treatment on wheat seed viability. Contaminated ‘Stephens’ and ‘Daws’ winter wheat seed lots were exposed for 15, 30, or 60 s to 0, 0.07, 0.13, 0.27, or 0.67 M NaOCl solutions heated to 50, 55, or 60 °C. Wheat seed quality and teliospore viability were determined by standard germination tests and by lipase assays, respectively. Maximum teliospore mortality was achieved when the NaOCl concentration was ≥0.13 M . Stephens germination was generally not reduced by NaOCl heated to 50 and 55 °C, regardless of exposure time, but was reduced at 60 °C when exposed for 60 s. Germination was proportionally reduced by increased NaOCl concentration and time of NaOCl exposure. Daws was more susceptible to high‐temperature NaOCl treatment than Stephens. Seedling coleoptile length of both cultivars was not reduced when seed was exposed for ≤30 s to 0.13 M NaOCl when treatment temperature was ≤55 °C. The safest NaOCl concentration for killing teliospores on seed of both cultivars was 0.13 M when treatment temperature was ≤55 °C. Germination was similar regardless of seed moisture content prior to NaOCl treatment. The high‐temperature NaOCl treatment may be an important tool for solving phytosanitary restrictions imposed due to the presence of teliospores of T. controversa on wheat grain and seed.