Diversity Analysis of Bangladeshi Coastal Rice Landraces (Oryza sativa) for Morpho-Physiological and Molecular Markers’Responses to Seedling Salinity Tolerance

Development of salt tolerance in rice through breeding program is mainly depends on the salinity responses of thepotential rice germplasms. Coastal rice landraces of Bangladesh possess diverse morphological and physiological responses to salinity. Hence, our target is to identify candidate salt-tolerant coastal rice genotypes as a new source of salt tolerance (12 dS/m). Here, weannotated 20 Bangladeshi coastal Aus landrace rice regarding their phenotypic and genetic relatedness to salinity tolerance throughmultivariate analyses of five morpho-physiological traits namely, salt injury score (SIS), ion-leakage, chlorophyll concentration,root-shoot reduction percentage and profiling of DNA using simple sequence repeat (SSR). Based on the standard evaluation score(SES) the salt-induced coastal rice landraces were grouped into highly susceptible (HS), susceptible (S), moderately tolerant (MT),tolerant (T) and highly tolerant (HT). Besides, a canonical discrimination analysis of the mean trait values of five morpho-physiologicalparameters confirmed the above mentioned five categories of salinity tolerance. Based on all morpho-physiological parameters onegenotype (Kalihytta) as highly tolerant (HT), two genotypes (Manikmuri and Monsur IRRI) as tolerant (T) and five genotypes (Nara,Iratom 27, Matichak, Abdul high IRRI and Parija) were identified as moderately tolerant (MT) against salinity. Finally, the molecularcharacterization using two SSR markers (RM493 and RM3412) revealed Kalihytta, Nara, Iratom 27, Parija, Lal jamaibabu andFullbadam, as tolerant against salt stress. Our candidate salt tolerant Aus rice genotypes could be useful as novel sources of salttolerance for thriving salt-tolerant high yielding varieties in the coastal ecosystem of Bangladesh.