TITLE:
QTL Mapping for Partial Resistance to Southern Corn Rust Using RILs of Tropical Sweet Corn
AUTHORS:
Kitti Wanlayaporn, Jetsada Authrapun, Apichat Vanavichit, Somvong Tragoonrung
KEYWORDS:
Sweet Corn; Southern Corn Rust; Partial Resistance; Quantitative Trait Loci (QTLs); Combined across Locations
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.4 No.4,
April
23,
2013
ABSTRACT: Southern corn
rust is one of destructive diseases in maize caused by Puccinia polysora Undrew. A mapping population of tropical sweet corn recombinant inbred lines
(RILs) derived from a cross between hA9104 and hA9035 inbred lines were set up
to detect quantitative trait loci (QTLs) involved in partial resistance to
southern corn rust. Eighty nine RILs were used to evaluate resistance levels
using nine-point relative scale (1-9) at Sweet Seeds, Suwan Farm, Thailand include
combined analysis. A genetic linkage map was constructed with 157 SSR markers,
with a total length of 2123.1 cM,
covering 10 chromosomes. Broad-sense heritability of individual location ranged
from 0.76 and 0.82 and combined across locations was 0.87. Multiple QTL mapping
(MQM) was applied for the identification of the QTLs. Fifteen QTLs were
detected on chromosome 1, 2, 5, 6, 9 and 10 in both locations and combined across locations.
QTLs on chromosome 1, 5 and 6 were contributed by alleles of resistant
parent hA9104 while others were contributed by alleles from the susceptible
parent, hA9035. Phenotypic variance of each QTL explained ranged from 6.1% to 41.8% with a total of 69.8% - 81.9%. QTL on chromosome 1, 6
and 10 were stable QTLs detected in both locations.