Quantitative Trait Loci Analysis of Maize (Zea mays L.) for Maize Streak Virus Resistance

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.