Thai jasmine rice cultivar KDML105 carrying Saltol QTL exhibiting salinity tolerance at seedling stage

• Published in: Molecular breeding 2016-11, Vol.36 (11), p.1-13, Article 150
• Main Authors: Punyawaew, K., Suriya-arunroj, D., Siangliw, M., Thida, M., Lanceras-Siangliw, J., Fukai, S., Toojinda, T.
• Format: Article
• Language: English
• Subjects: Abiotic stress; Agronomy; Alleles; Amylose; Biomedical and Life Sciences; Biotechnology; Cooking; Cultivars; Gene mapping; Heating; Homeostasis; Jasmine; Jasminum; Life Sciences; Molecular biology; Oryza; Plant biology; Plant Genetics and Genomics; Plant growth; Plant Pathology; Plant Physiology; Plant Sciences; Quantitative trait loci; Saline water; Salinity; Salinity effects; Salinity tolerance; Salts; Seedlings; Stresses
• ISSN: 1380-3743; 1572-9788
• DOI: 10.1007/s11032-016-0574-8

Saltol , the major salinity tolerance quantitative trait loci (QTL) in rice, was introgressed from IR66946-3R-230-1-1 (FL530) into Khao Dawk Mali 105 (KDMl105) by two rounds of marker-assisted backcrossing (MAB). Twenty-eight BC 2 F 2 introgression lines (BILs) with positive Saltol allele (BIL +Saltol ) and 19 BILs with negative Saltol allele (BIL −Saltol ) were validated for the effect of Saltol as key salinity tolerant trait at seedling stage. A hydrophonic system with salt stress of 12 dS m −1 (130 mM Na + ) was conducted, and significant differences between BILs +Saltol and BILs −Saltol were observed for the period of plant survival (PPS), total K + (T-K + ) and Na + (T-Na + ) concentration, whole plant Na + -K + ratio (T-Na + /K + ), shoot Na + (S-Na + ) and K + (S-K + ) concentration, and shoot Na + -K + ratio (S-Na + /K + ). BILs +Saltol displayed higher PPS, uptake less Na + (T-Na + ; 43.4 ppm), and more K + (T-K + ; 30.9 ppm), while the BILs −Saltol uptake more Na + (T-Na + ; 45.7 ppm) and less K + (T-K + ; 28.2 ppm). Direct effects on PPS and salt injury score (SIS) were observed, indicating Na + /K + homeostasis mechanism by the Saltol under hydrophonic salt stress. All BILs +Saltol recovered KDML105 cooking quality profile such as low apparent amylose content (AAC), high score of alkaline spreading value (ASV), intermediate gel consistency (GC), and strong fragrance. However, variation in agronomic traits was observed. The possibility of lowering S-Na + /K + ratio under salt stress at seedling stage in KDML105 by introgression of the Saltol was demonstrated. Currently, BC 2 F 7 of the BIL +Saltol selected lines are being tested for salinity tolerance in the salt-affected areas in the northeast of Thailand.