Assessment of Salinity Tolerance and Analysis of SSR Markers Linked with Saltol QTL in Sri Lankan Rice (Oryza sativa) Genotypes

Aim: This research was aimed at assessing Sri Lankan rice varieties for the salinity tolerance using morphological traits and to analyze the SSR markers closer to Saltol QTL of the chromosome 1 to be used in rice breeding and gene mapping studies.

Place and Duration of Study: The research was conducted at the Faculty of Agriculture and Plantation Management, Wayamba University of Sri Lanka, from April 2013 to October 2013.

Study Design: Morphological traits were analyzed by ANOVA and polymorphic bands obtained from SSR markers were analyzed by Jaccard’s similarity coefficient following the unweighted pair group method with arithmetic mean (UPGMA).

Methodology: Morphological traits of twenty rice germplasm of Sri Lankan origin, including traditional and improved varieties were assessed under 12 dS/m saline stress and five SSR markers located between 10 -15 Mb to Saltol QTL were analyzed in relation to salinity tolerance.

Results: A novel weighted indicator, Salinity Survival Index, revealed that Goda Wee, At354 and Al Wee varieties were highly salinity tolerant compared to the tested varieties including an accession of Pokkali and the morphological traits also showed the same validation. Diversity analysis of SSR marker alleles linked with Saltol QTL clustered the salinity tolerant and salinity susceptible germplasms as compatible with the distribution pattern of salinity survival index and the marker, RM1287 was more informative for the screening of rice germplasm for salinity tolerance.

Conclusion: Information derived on morphological traits under salinity stress and the polymorphic SSR marker patterns obtained from tolerant and susceptible varieties near Saltol region would be useful in selecting parental lines from the tested varieties for rice breeding and gene mapping programs designed for salt tolerance