Simulating the effect of terminal drought stress by potassium iodide and its use in mapping QTLs for yield and yield components in bread wheat.

Terminal drought is the most important and dominating stress in areas of wheat cultivation with Mediterranean climates as prevails in Iran. However, evaluation of plants response to natural drought is difficult due to lack of uniform drought stress in the field. Successful experiments of simulating the effect of terminal drought by chemical desiccants like potassium iodide (KI) during grain filling have already been reported. In the present work we evaluated a mapping population of 118 F2:7 recombinant inbred lines (RILs) from a cross between a typical Iranian drought tolerant landrace Tabassi and a highly bred and non-drought tolerant European wheat variety Taifun for yield and yield component QTLs in three drought stress environments i.e. (1) under natural post anthesis drought stress in Iran, (2) under drought conditions provided by an electro automated shelter in Hungary, and (3) under a potassium iodide induced post anthesis drought applied in Austria. In this paper, the efficiency of KI treatment to simulate the effect of post anthesis drought and its utilization for QTL mapping in comparison with a natural drought stress is discussed.