Molecular Breeding to Improve Salt Tolerance of Rice (Oryza sativa L.) in the Red River Delta of Vietnam

Le Hung Linh,Le Huy Ham,Abdelbagi M Ismail,Tran Dang Khanh,Ta Hong Linh,Tran Dang Xuan

doi:10.1155/2012/949038

Abstract

Rice is a stable food in Vietnam and plays a key role in the economy of the country. However, the production and the cultivating areas are adversely affected from the threats of devastation caused by the rise of sea level. Using marker-assisted backcrossing (MABC) to develop a new salt tolerance rice cultivar is one of the feasible methods to cope with these devastating changes. To improve rice salt tolerance in BT7 cultivar, FL478 was used as a donor parent to introgress the Saltol QTL conferring salt tolerance into BT7. Three backcrosses were conducted and successfully transferred positive alleles of Saltol from FL478 into BT7. The plants numbers IL-30 and IL-32 in BC3F1 population expected recurrent genome recovery of up to 99.2% and 100%, respectively. These selected lines that carried the Saltol alleles were screened in field for their agronomic traits. All improved lines had Saltol allele similar to the donor parent FL478, whereas their agronomic performances were the same as the original BT7. We show here the success of improving rice salt tolerance by MABC and the high efficiency of selection in early generations. In the present study, MABC has accelerated the development of superior qualities in the genetic background of BT7.

Highlights

Salinity is one of the major impediments to enhancing production in rice growing areas worldwide
Our study focuses on combining the useful agronomic traits of BT7 with salt tolerance gene (Saltol) quantitative trait locus (QTL)/gen, which attached salt tolerance in backcross breeding lines by conversion to the recurrent parent genotype using molecular genotyping with simple sequence repeat (SSR) markers
Our results demonstrate that a major salt tolerance gene (Saltol) from the donor parent FL478 was successfully transferred into the BT7 genetic background and expressed similar phenotypic characteristics when compared with BT7

Summary

Introduction

Salinity is one of the major impediments to enhancing production in rice growing areas worldwide. The economic loss by salt intrusion in 2005 was up to 45 million USD, which is equivalent to 1.5% of annual rice productivity in the Mekong Delta [6] It has a salinity threshold of 3 dS/m, with a 12% reduction in yield per dS/m, beyond this threshold. In BC1F1, A total of 30 microsatellite markers were used for background selection in 25 BC1F1 plants resulting from foreground and recombinant selection (Figures 1 and 2). In the BC2F1 population, 43 polymorphic markers were used for background selection in 19 BC2F1 plants resulting from foreground and recombinant selection plants nos. 21 chromosomes 5 and 8 were of complete recipient types The recurrent genome recovered in the plants no.s IL-30 and IL32 is expected to be 99.2% and 100%, respectively (Figures 4 and 5)

Methods

Discussion

Conclusion