Association analysis of charcoal rot disease component traits in sorghum minicore germplasm with EST-SSR markers

Abstract

Sorghum is an important crop of semi arid regions where it
suffers from several biotic stresses. Among biotic stresses,
charcoal rot/stalk rot is a major constraint for rabi (post
rainy) sorghum production. Identification of stable resistant
sources and incorporation of the genes or quantitative trait
loci (QTL1) governing resistance are the prerequisite to
make progress in breeding for charcoal rot resistance. A
set of 242 sorghum minicore collection were phenotyped
in sick plot of charcoal rot disease. A total of 31 polymorphic
EST-SSR markers were developed and mapped through
association analysis. The population structure analysis
indicated the partitioning of the genetic population
structure into four clusters. In the current study six new
markers were identified for charcoal rot disease resistance
(Xiabt 210, Xiabt 527, Xiabt 301, Xiabt 37, Xiabt 77, Xiabt 81)
and was validated previously identified flanking markers
for charcoal rot disease QTLs (locus Xiabt 275) at RARS
Vijayapura location. Six marker trait associations were stable
at two locations and these significant associations are
useful and suitable for marker assisted selection in charcoal
rot disease resistance breeding programs.