Identification of QTLs for Morph-Physiological Traits Related to Salinity Tolerance at Seedling Stage in Indica Rice

This study was carried out to identify the QTLs, associated with salinity tolerance at seedling stage, in indica rice using. F2:3 populations. QTL mapping was performed using microsatellite markers. Twelve linkage groups, covering a total size of 1648.9 cM, with an average interval distance 15.2 cM, were made. A total of 22 QTLs were identified, 9 and 13 for four morphological and six physiological traits, respectively. Correlations between salt injury score (SIS) and physiological traits reflected that damage of leaves was attributed to accumulation of Na+ in shoot by transport of Na+ from root to shoot in external high concentration. Microsatellite locus, RM 80 on chromosome 8, was found to be associated with SIS, Na+, K+ and Na:K in shoot. The correlated traits were found to be associated with the same locus or very close on the same chromosomal region. The QTLs detected for Na+, K+ and Na:K in the shoots and the roots did not share the same map locations, suggesting that the genes controlling the transport of Na+ and K+ between the shoots and the roots may be different.