Univrsity of Tehran Press Iranian Journal of Field Crop Science 2008-4811 44 4 2013 12 22 Mapping of QTLs Controlling Tolerance to Drought and Salt Stress at Germination Stage of Rice Mapping of QTLs Controlling Tolerance to Drought and Salt Stress at Germination Stage of Rice 585 596 50340 10.22059/ijfcs.2013.50340 FA Babak Rabiei Associate Professor, Dept. of Agronomy and Plant Breeding, Faculty of Agricultural Sciences, University of Guilan, Iran 0000-0001-5432-4498 Zahra Mardani Former graduate Student, Dept. of Agronomy and Plant Breeding, Faculty of Agricultural Sciences, University of Guilan, Iran Hosein Sabouri Assistant Professor, Dept. of Plant Production, Faculty of Agriculture and natural resources, Gonbad Kavous University, Iran Atefeh Sabouri Assistant Professor, Dept. of Agronomy and Plant Breeding, Faculty of Agricultural Sciences, University of Guilan, Iran Journal Article 2012 10 21 Salinity and drought are two major abiotic stresses that affect rice (<em>Oryza sativa</em> L.) production in worldwide. Salt and drought tolerance and high seedling vigor of rice is one of the important traits in the establishment of seedling in direct planting system and saline and drought environments. In this research, the mapping population of F_2:4 families derived from the cross between local variety Gharib (salt and drought tolerant) and improved variety Sepidroud (salt and drought sensitive) was used for identification of molecular markers linked to salt and drought tolerant genes at Faculty of Agriculture and Natural Resources, Gonbad Kavous University and Biotechnology Laboratory, Guilan University in 2010-2012.  A linkage map of 2475.7 cM with an average interval of 10.48cM was constructed using 105 AFLP markers and 131 SSR markers. QTL analysis using composite interval mapping detected ten QTLs for germination stress index, vigour seed index, traits germination rate, germination percentage, radicle length, plumule length, coleorhiz length, plumule dry weight, coleoptile fresh weight and seedling dry weight under drought stress conditions of either mannitol (8) and salinity (8 dS). Among the identified QTLs, seven QTLs associated with drought stress, and seven QTLs associated with salt stress, explained over 15% of the total phenotypic variance of traits. It seems that these QTLs can be the major QTLs controlling traits of drought and salinity tolerance and with more confidence they could be used in marker assisted selection program. Salinity and drought are two major abiotic stresses that affect rice (<em>Oryza sativa</em> L.) production in worldwide. Salt and drought tolerance and high seedling vigor of rice is one of the important traits in the establishment of seedling in direct planting system and saline and drought environments. In this research, the mapping population of F_2:4 families derived from the cross between local variety Gharib (salt and drought tolerant) and improved variety Sepidroud (salt and drought sensitive) was used for identification of molecular markers linked to salt and drought tolerant genes at Faculty of Agriculture and Natural Resources, Gonbad Kavous University and Biotechnology Laboratory, Guilan University in 2010-2012.  A linkage map of 2475.7 cM with an average interval of 10.48cM was constructed using 105 AFLP markers and 131 SSR markers. QTL analysis using composite interval mapping detected ten QTLs for germination stress index, vigour seed index, traits germination rate, germination percentage, radicle length, plumule length, coleorhiz length, plumule dry weight, coleoptile fresh weight and seedling dry weight under drought stress conditions of either mannitol (8) and salinity (8 dS). Among the identified QTLs, seven QTLs associated with drought stress, and seven QTLs associated with salt stress, explained over 15% of the total phenotypic variance of traits. It seems that these QTLs can be the major QTLs controlling traits of drought and salinity tolerance and with more confidence they could be used in marker assisted selection program. https://ijfcs.ut.ac.ir/article_50340_4cd436bf13296d674d046c80f7e7ecde.pdf