Locus RM22418 on the short arm of Chr. 8 also showed a significant association with salinity tolerance, corresponding to the physical position of 3326 kb in Nipponbare genome. QTL for traits related to salt tolerance have been detected repeatedly in this region (Table S4). The QTL in RM38-RM25 (2115–4378 kb) interval showed significant effect to score of salt toxicity of leaves and survival days of seedlings at the seedling stage, as well as fresh weight at the tillering stage [25]. A QTL was also identified for Na+ in straw at high salt in the interval of RM1235-RM25 (1209–4378 kb) accounting for 14.05% of the total variation [26]. These results suggested that RM22418-contained region were essential for rice growth under salt stress.
In summary, of 86 southern Bangladeshi rice landraces, 11 (12.6%) were identified as having seedling tolerance (SES score 3.0) to salt stress, and 25 (28.7%) were moderately tolerant. These accessions could be suitable sources of salinity tolerance in breeding programs.