Submitted to: Meeting Abstract
Publication Type: Proceedings
Publication Acceptance Date: 7/1/2009
Publication Date: 10/18/2009
Citation: Ni, X., Xu, W., Blanco, M.H., Wilson, J.P., Buntin, G. 2009. Evaluation of elite corn inbred lines and hybrids for multiple ear-colonizing insect resistance. In: Proceedings of the 6th Asia-Pacific Congress of Entomology, October 18-22, 2009, Beijing, China. p. 324-325. Interpretive Summary: not required
Technical Abstract: Multiple ear-colonizing insects and diseases are critical impediments for corn production in the southern US states. These pests reduce yield and impose health threats by aflatoxin and fumonisin contaminations in the grain. Insect damage on corn ears was evaluated in 20 elite inbred lines and 20 hybrids from the Germplasm Enhancement of Maize (GEM) Project in 2007 and 2008 with a local resistant and susceptible control for inbred lines and hybrids, respectively. Insect damage on corn ears was separated as ear and kernel damage using four parameters. Ear penetration was used to assess corn earworm [Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae)] and fall armyworm [Spodoptera frugiperda (JE Smith) (Lepidoptera: Noctuidae)] feeding on corn cobs, while kernel damage was further separated into three parameters. They are: 1) percentage of discolored kernels by the stink bugs [that is, the brown stink bug, Euschistus servus (Say) and the southern green stink bug, Nezara viridula (L.) (Heteroptera: Pentatomidae)]; 2) percentage of maize weevil [Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae)]-damaged kernels with small uniform holes, and 3) percentage of kernels with irregular damage symptom caused by three other insect pests [that is, sap beetle, Carpophilus spp. (Coleoptera: Nitidulidae), chocolate milkworm,Moodna spp. (Lepidoptera: Pyralidae), and pink scavenger caterpillar, Pyroderces (Anatrachyntis) rileyi (Walsingham) (Lepidoptera: Cosmopterigidae)]. The smut infection was only assessed on the GEM inbred lines, but no smut infection was found on the GEM hybrids. In addition, ear protection traits (i.e., husk tightness and extension) were also examined. Significant difference was detected on the six parameters among the GEM inbred and hybrid entries. The correlation among all damage assessment parameters was also examined. Nine of the 20 GEM inbred lines and 8 of the 20 GEM hybrids were identified as multiple insect resistant. The tactics and ramifications of developing multiple insect-resistant corn inbred lines and experimental hybrids will also be discussed.