Induced Resistance to Wheat Yellow Rust by Chemical Inducers

Abstract

Four chemical inducers, DL-?-aminobutyric acid (BABA) and salicylic acid (SA) at 0, 250, 500 and 1000 µgml^-1, Benzothiadiazole (BTH) at 0, 0.3, 0.6 and 1mM and Indole acetic acid (IAA) at 0, 25, 50 and 100 µg ml^-1 were applied as foliage spray on two genotyps of wheat,Tamuz-2 and AL-8/70 to assess their ability to induce resistance against stripe  (Yellow ) rust disease (Srd) caused by Puccinia striiformis west. f.sp. tritici. Field trail was conducted during 2012/13 growing season in Bakrago experimental research station, Sulumani Province under natural infection conditions. All the test chemicals significantly (p=0.05) reduced disease severity (DS), coefficient of infection (C.I) and rate of infection (r). BABA and SA at 1000 µgml^-1, IAA at 100 µgml^-1 and BTH at 1 mM were the most effective treatments for induction of rust resistance in cv. Tamuz-2. Similar reduction in the above mentioned disease parameters were observed in cv. AL-8/70 when plants were treated with the high test concentrations of IAA, BTH, BABA and SA. However, the two cultivars reacted differently toward the chemical inducers in terms of rust disease development. Further research work is needed before effective and practical management of wheat stripe rust disease can be achieved by chemical inducers.

Keywords: Induced resistance, Puccinia striiformis f.sp. tritici, Chemical inducer, Wheat, Disease severity.