Mapping QTLs Linked to Some Traits Related to Drought Stress in Rice

Identification of markers linked to genes controlling drought tolerance is necessary to breed high-yielding rice varieties for drought-prone areas. In the current study, some traits associated with drought tolerance in rice were investigated using microsatellite marker. One hundred and ninety two individuals and families derived from a cross between two genetically divergent, Shahpasand (tolerant) and IR28 (sensitive), were grown in Gonbad Kavous University to detect QTLs for traits related to drought tolerance on chromosomes 1 and 6. Linkage map was derived using 33 polymorphic markers in 2 linkage groups in parents and 192 F2 individuals. This map covered 366 cM of the rice genome. A total of 16 QTLs were detected for traits. The co-location of QTLs for traits for drought tolerance was shown to be on chromosome 1 in RM8115-RM5638 and chromosome 6 in RM7434-RM162 and RM4608-RM217 intervals. The results showed that QTLs controlling LFI (qLFI-1) overlapped with the QTLs for leaf rolling (qROL-1) on chromosome 1. Three QTLs were mapped for fertility (FER). Two QTLs were showed the large effects on the ROL and FER that explained 14.11% and 14.65%, respectively, of the total phenotypic variations. These QTLs may be useful for development of new varieties with a high level of grain yield under drought conditions. Since these regions explained significant percentage of the phenotypic variations, they have potential for being applied in selection programs using a marker for drought tolerance.