Molecular mapping of quantitative trait loci (QTL) for salinity tolerance in Japonica rice (Oryza sativa L.) at seedling stage using microsatellite markers

Date

4-2007

Degree

Bachelor of Science in Biology

Major Course

Major in Cell Biology

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Cecilia S. Reamillo

Co-adviser

Rakesh Kumar Singh

Abstract

Microsatellite markers or simple sequence repeats (SSR) were utilized to determine salinity tolerance in an F2 population of the cross between IR73571-3B11-K2 (a tongil type rice line) and Hwayoungbyeo (a japonica cultivar). Phenotyping of the 185 individuals of the F2 population and their parents at the seedling stage was done using salinized culture solution (salinized at EC 12 dS/m and EC 18 dS/m) under controlled conditions. Standard evaluation screening (SES) scores was used in scoring salinity tolerance at the seedling stage. Physiological analysis of the F2 population was done by measuring the Na' and compartmentalization in the leaves, and the ratio of Na'/K'. A total of 47 microsatellite markers were utilized for constructing linkage maps for the 12 chromosomes. Through interval mapping, QTLs associated with salt injury tolerance in chromosome 1 were tagged in the region between markers RM562 and RM493, with a LOD value of 4.3. Based on the ratio of Na/K in the leaves, a QTL was tagged in the region of the marker RM562 in chromosome 1 with a LOD value of 3.9. Single marker analysis revealed possible QTLs for salt injury tolerance and K+ compartmentalization in RM23 and RM1287 in chromosome 1, and a possible QTL for salt injury tolerance and Na* compartmentalization was also revealed by RM537 on chromosome 4. Graphical genotype maps were created for chromosomes 1, 2, 5, and 6 where possible QTLs were detected for salt injury tolerance and K+ compartmentalization based on correlated data from single marker analysis and interval map values by using the Kosambi map function. In chromosome 1, for the salt injury tolerance trait and K' uptake trait, a greater percent of the genome was from the tolerant parent (66.6% and 70.9%, respectively). In chromosome 2, for the salt injury tolerance trait, 53% of the genome of the progeny was largely contributed by the heterozygous parents. In chromosome 5, 30.6% of the genome of the progeny was contributed by heterozygous parents. For chromosome 6, 57.5% of the genome was contributed by the tolerant parent for the salt injury tolerance trait. The map revealed that 36.2 % of the F2 population showed introgression of the salinity tolerance genes from the IR73571 parent.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

Thesis

Document Type

Thesis

This document is currently not available here.

Share

COinS