Quantitative Trait Loci Analysis of Maize (Zea mays L.) for Maize Streak Virus Resistance
P. Arusei *
Department of Biological Sciences, Moi University, P.O.Box 3900-30100 Eldoret, Kenya.
S. Runo
Department of Biochemistry and Biotechnology, Kenyatta University, P.O.Box 43844 Nairobi, Kenya.
M. Warigia
Department of Biochemistry and Biotechnology, Kenyatta University, P.O.Box 43844 Nairobi, Kenya.
A. Ngetich
Jomo Kenyatta University of Agriculture and Technology, P.O.Box 62000-00200 Nairobi, Kenya.
P. Leley
Kenya Agricultural and Livestock Research Organization, P.O.Box 57811, 00200 Nairobi, Kenya.
*Author to whom correspondence should be addressed.
Abstract
Aims: This study was conducted to evaluate partial resistance to Maize Streak Virus (MSV) in F2 segregating population derived from a single cross of two inbred lines VLO73311 (resistant) and CLRCW92 (susceptible).
Study Design: The experimental design was an incomplete block design replicated two times.
Place and Duration of Study: Department of plant sciences Kenya Agricultural and Livestock Research Institute in Biotechnology center laboratory, in June 2014 to December 2015.
Methodology: Resistance was evaluated in replicated field trials under artificial inoculation while selecting using SNP markers. The method of composite interval mapping was employed for QTL detection with a linkage map based on 350 SNP markers.
Results: The final linkage map comprised of 100 individuals and 61 SNP markers distributed in ten linkage maps and covering a distance of 437.282cM. One QTL located in linkage group four was detected with a LOD score of above 2.0 with two SNP markers (PZA00413_20 and PZA03198_3) tightly linked to the QTLs. A significant QTL explaining 14% of the phenotypic variance for early resistance to MSV was detected on chromosome three.
Conclusion: The SNPs significantly associated with MSV resistance can be used in marker-assisted selection and will accelerate the breeding process for the development of MSV resistant maize genotypes.
Keywords: MSVD, QTLS, resistance, maize, SNP markers.