Allele mining of HKT1;5 from O. sativa and O. glaberrima. Sequencing and phylogeny of HKT1;5 from O. sativa and O. glaberrima. A. Regions amplified and sequenced. These total approximately 6.5 kb, including the full coding region and approximately 3.5 kb of promoter. Exons of the OsHKT1;5 gene are shown as filled, linked arrows, primers/PCR products by linked green and red arrows. B. Minimum-evolution tree of sequenced regions, based on the number of differences (10,000 bootstrap replicates, pairwise deletion of gaps). Selected lines possessing each allele are indicated. Yellow shading indicates high tolerance and high Na+ exclusion, and green indicates moderate tolerance and exclusion. Blue shading indicates sensitivity and low Na+ exclusion. The Daw allele lines (unshaded) are tolerant/highly tolerant but do not show the same amount of Na+ exclusion. Other unshaded lines have not been tested for salinity tolerance or leaf Na+ concentrations.