Leaf Na+ effects and multi-trait GWAS point to salt exclusion as the key mechanism for reproductive stage salinity tolerance in rice.

Background And Aims: Since salinity stress may occur across stages of rice (Oryza sativa L.) crop growth, understanding the effects of salinity at reproductive stage is important although it has been much less studied than at seedling stage.

Methods: In this study, lines from the Rice Diversity Panel 1 (RDP1) and the 3000 Rice Genomes (3KRG) were used to screen morphological and physiological traits, map loci controlling salinity tolerance through genome-wide association studies (GWAS), and identify favorable haplotypes associated with reproductive stage salinity tolerance.

QTL mapping under salt stress in rice using a Kalarata-Azucena population.

Unlabelled: Salt stress is a major constraint across large rice production areas in Asia, because of the high sensitivity of modern rice varieties. To identify quantitative trait loci (QTL) associated with salt tolerance in rice, we developed an F population from a cross between the salt-tolerant landrace, Kalarata, and the salt-sensitive parent, Azucena. F3 families from this population were screened and scored for salt tolerance using IRRI's (SES).

A GWAS approach to find SNPs associated with salt removal in rice leaf sheath.

Background And Aims: The ability for salt removal at the leaf sheath level is considered to be one of the major mechanisms associated with salt tolerance in rice. Thus, understanding the genetic control of the salt removal capacity in leaf sheaths will help improve the molecular breeding of salt-tolerant rice varieties and speed up future varietal development to increase productivity in salt-affected areas. We report a genome-wide association study (GWAS) conducted to find single nucleotide polymorphisms (SNPs) associated with salt removal in leaf sheaths of rice.

Assessing trait contribution and mapping novel QTL for salinity tolerance using the Bangladeshi rice landrace Capsule.

Background: Salinity is one of the most widespread abiotic stresses affecting rice productivity worldwide. The purpose of this study was to establish the relative importance of different traits associated with salinity tolerance in rice and to identify new quantitative trait loci (QTL) conferring tolerance to salinity at seedling stage. A total of 231 F plants derived from a cross between a sensitive variety BRRI dhan29 (BR29 hereafter) and Capsule, a salt tolerant Bangladeshi indica landrace, were evaluated under salt stress in a phytotron.

Fundamental parenchyma cells are involved in Na and Cl removal ability in rice leaf sheath.

Salt sensitivity in rice plants is associated with the accumulated amount of Na+ and Cl- in shoots and, more significantly, in photosynthetic tissues. Therefore, salt removal ability at the leaf sheath level is an important mechanism of salt tolerance. In the present study we attempted to determine whether rice leaf sheaths excluded Cl- as well as Na+, and to identify the tissues that were involved in the removal ability of both ions.

Exploring novel genetic sources of salinity tolerance in rice through molecular and physiological characterization.

Background And Aims: Agricultural productivity is increasingly being affected by the build-up of salinity in soils and water worldwide. The genetic base of salt-tolerant rice donors being used in breeding is relatively narrow and needs broadening to breed varieties with wider adaptation to salt-affected areas. This study evaluated a large set of rice accessions of diverse origins to identify and characterize novel sources of salt tolerance.