Saline stress severely affects rice (Oryza sativa L.) growth and development and reduces crop yield. Therefore, developing salt-tolerant and high-yielding rice using quantitative trait loci (QTLs) and linkage markers is a priority for molecular breeding.
In a study published in Agronomy, researchers from Xishuangbanna Tropical Botanical Garden (XTBG) first used the salt-tolerant germplasm SR86 to cross with salt-sensitive japonica variety Dianjingyou1 (DJY1) to generate F1 and F2 populations, and cross with Yunnan japonica rice to generate introgression lines, respectively.
The researchers identified a QTL designated as qST1.1 that played a significant role in salt tolerance in SR86 grown under soil conditions. This QTL was further validated by homozygous substitution lines and introgression lines.
This qST1.1 not only improves the ability of plants to resist salt stress, but also does not affect yield; it therefore shows potential as a genetic resource for breeding salt-tolerant rice using MAS.
They further applied salt stress using high concentrations of NaCl in soil, and the saline soil environment was simulated to avoid undue disturbance of normal growth conditions.
The results showed that the methods we used in this study were able to provide a new and effective way to select salt-tolerant rice varieties.
Furthermore, the identification of qST1.1 enabled analysis of the major salt-tolerant gene of SR86.
Finally, by investigating some yield characteristics of the introgression lines (ILs), they found that the ILs not only showed high salt tolerance, but also had high yield and high quality, and thus might provide potential resources for rice breeding.
XU Peng Principal Investigator
Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun 666303, Yunnan, China