Abstract:

Maize ear rot, mainly caused by Fusarium moniliforme, is one of the most destructive diseases of maize in the world. Infected maize is lower yielding and contains toxins that are dangerous to livestock and human. The aims of this study were to identify quantitative trait loci (QTL) associated with genetic resistance to F. moniliforme, their positions and effects in the maize genome; investigate the consistency of QTL across two environments and their utilization in a marker-assisted selection programme. A previous genetic map containing 88 AFLP and 151 microsatellite markers and 230 F₂ plants were used for QTL mapping in Maize. QTL analysis was performed using joint composite interval mapping. In Ya’an, six QTL conferring Fusarium moniliforme ear rot resistance on chromosomes 2, 3, 4, 6, and 9 were detected and explained 8.3%–25.7 % of the phenotypic variance; while in Mianyang, four QTL were identified on chromosomes 1, 6, 7, and 9 that accounted for 11.3%–26.4% of the total phenotypic variance. Two QTLs on chromosomes 6 and 9 were identified consistently in both environments, which revealed that resistance to F. moniliforme was determined by genetic factors. Three QTLs on chromosomes 1, 6 and 7 that accounted for 8.9%–17.2% of the total phenotypic variance were detected using the mean resistant disease index of two locations. QTL mapping results will be helpful to further understand genetic basis of ear rot resistance in maize and lay a basis for marker-assisted selection for the resistance species.

Key words: Maize (Zea mays L.), Ear rot, SSR, AFLP, QTL mapping