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Quantitative
trait loci for resistance to maize streak virus disease in
maize genotypes used in hybrid development
Martin Lagat,
Jedidah Danson*, Michael Kimani and Alex Kuria
Biotechnology Center, Kenya Agricultural Research Institute,
P.O. Box 58711-00200, Nairobi, Kenya.
*Corresponding author. E-mail:
j.danson@cgiar.org.
Accepted 6 June, 2008 |
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Maize streak virus disease is
an important disease of maize in Kenya. In this study, we
mapped and characterized quantitative trait loci affecting
resistance to maize streak virus in maize populations of S4
families from the cross of one resistant MAL13 and one
susceptible MAL9 recombinant inbred lines. Resistance was
evaluated in replicated field trials under artificial
inoculation while selecting using microsatellite markers.
The method of composite interval mapping was employed for
QTL detection with a linkage map based on 13 polymorphic
microsatellite markers. Phenotypic variances for maize
streak virus resistance were highly significant in the
population, where the three families were selected. The
three families expressed acceptable levels of resistance
(1.0 - 1.5) with virus pressure.
The three QTLs were for umc2228 with LOD score of 27.7 and
explained 93% of the variance, umc2229 with LOD of 13 and
explained 78.9% of the variance, and bnlg1832 with LOD of
18.7 and explained 71.3% of the variance. A total of 95% of
the lines in the three families were found to be resistant
to maize streak virus disease.
Key word: MSVD, QTLS, resistance, maize, SSR markers. |
