Quantitative Trait Locus Mapping of Salt Tolerance in Wild Rice Oryza longistaminata.

Lei Yuan,Gaili Chen,Shaoying Huang,Shaoqing Li,Jianxiong Li,Xiao Wei,Fengfeng Fan,Nannan Li,Ruihua Wang,Licheng Zhang

doi:10.3390/ijms23042379

Abstract

Salt stress is one of the most severe adverse environments in rice production; increasing salinization is seriously endangering rice production around the world. In this study, a rice backcross inbred line (BIL) population derived from the cross of 9311 and wild rice Oryza longistaminata was employed to identify the favorable genetic loci of O. longistaminata for salt tolerance. A total of 27 quantitative trait loci (QTLs) related to salt tolerance were identified in 140 rice BILs, and 17 QTLs formed seven QTL clusters on different chromosomes, of which 18 QTLs were derived from O. longistaminata, and a QTL for salt injury score (SIS), water content of seedlings (WCS) under salt treatment, and relative water content of seedlings (RWCS) was repeatedly detected and colocalized at the same site on chromosome 2, and a cytochrome P450 86B1 (MH02t0466900) was suggested as the potential candidate gene responsible for the salt tolerance based on sequence and expression analysis. These findings laid the foundation for further improving rice salt tolerance through molecular breeding in the future.

Highlights

Soil salinity is one of the major environmental stress factors limiting the growth and yield of rice around the world [1], more than one third of the world’s irrigated lands are salinized to varying degrees [2]
In order to know if the wild rice O. longistaminata harbor favorable genes for salt tolerance, we investigated the performance of the O. longistaminata backcross inbred line (BIL) lines treated with
We found that the water content is the most sensitive to the salt treatment than the others (Table 1); correlation analysis revealed that the water content showed the highest coefficient of variation with the salt injure score, and showed a relatively stable and high correlation with the other five indicators (Figure 2), meaning that the water content in rice tissues is disturbed by the salt stress

Summary

Introduction

Soil salinity is one of the major environmental stress factors limiting the growth and yield of rice around the world [1], more than one third of the world’s irrigated lands are salinized to varying degrees [2]. Rice, which feeds more than half of the world’s population, is the most salt-sensitive cereal crop plant [3]. Developing salt-tolerant rice varieties is the most effective and economical way to improve yield and expand rice production in salinized areas. Rice responds differently to salt stress at different growth stages; seedling and reproductive stages are relatively more sensitive, and germination, tillering, and maturity stages are relatively more tolerant to salt stress [6].

Methods

Results

Conclusion