QTL mapping of agronomic traits in maize (Zea mays L.) grown in a low- phosphorus environment

Growing maize in soils that lack available phosphorus, an essential nutrient for plant growth, can lead to dwarf plants with weak roots and small leaves. It is also difficult for plants to absorb phosphorus from the soil environment. Developing maize varieties that efficiently utilize phosphorus would help to overcome this problem. However, relevant QTL need to be identified to achieve this goal. In this study, a QTL analysis was conducted of a maize F _2:3 population grown in a low-phosphorus soil environment at three different planting sites. The population consisted of 180 individual plants produced from a cross between a high-phosphorus efficiency genotype (082) and a low-phosphorus efficiency genotype (Ye107). The QTL analysis identified five stable QTLs associated with several important agronomic traits. The QTLs were identified in the same marker interval in the populations planted at the three different planting sites. Four QTLs identified the mapping population at one planting site were close to the five QTLs in the joint analysis of all planting sites, indicating that there may be common QTLs near these markers. Some one-cause-multiple-effect QTLs that may share genetic mechanisms were detected on chromosomes 1, 3, 4, 7, 9 and 10. These were QLA1-1 and QLW1-3, QLA3-1 and QLL3-3, QLA4-1 and QLL4-2, QPH7-1 and QTBN7-3, QPH9-2 and QTBN9-4, QLA9-1, QSD9-3 and QLW9-6, LA10-1 and QLW10-3, QLA10-1 and QLW10-3, and QLW10-3. QLW9-6, and LA10-1 and QLW10-3. This study provides a foundation for marker-assisted breeding of maize under low-phosphorus conditions.