Running title: Regulatory network for leaf angle on eight nodes in maize

32 Leaf angle (LA) is one of the most important canopy architecture traits of maize (Zea 33 mays L.). To date, there is an urgent need to characterize the genetic control of LA at 34 multiple nodes to bridge the information gap remain in optimizing canopy 35 architecture for maximum yield at different canopy levels. In this study, through the 36 cross between B73 (compact plant architecture) and SICAU1212 (expanded plant 37 architecture), 199 derived RIL families were used to perform QTL mapping for LA 38 from eight leaves at different nodes in three environments, utilizing 39 single-environment analysis and joint mapping. Combining the results of two 40 mapping strategies, we identified 15 common QTL associated with LA at eight nodes. 41 The phenotypic variation explained by the individual QTL ranged from 0.39% to 42 20.14% and the number of leaves controlled by a single QTL varied from 1 to 8. 43 Among them, QTL qLA2.1 and qLA5.1 simultaneously controlled LA of all the eight 44 nodes; however, qLA2.2 only affected that of 1stLA. The total phenotypic variation 45 explained by all QTL identified for LA at eight nodes ranged from 15.69% (8thLA) to 46 51.73% (1stLA). The number of QTL detected for LA at each nodes ranged from 4 47 (7thLA) to 11 (1stLA). These results provide comprehensive insights into the 48 molecular bases of regulatory networks in LA morphogenesis, and will benefit the 49 molecular design breeding of ideotype and further cloning of LA QTL at different 50 plant levels in maize. 51