2012 Annual Report
Superior backcross-derived lines combining resistance to Fusarium ear rot and hybrid yield potential were identified and advanced to 2nd year yield trials. 50 advanced lines from the USDA Germplasm Enhancement of Maize (GEM) project and the North Carolina State University maize inbred development programs were tested for resistance to Fusarium ear rot and fumonisin contamination resistance. 100 GEM lines were tested for resistance to southern leaf blight.
Several loci associated with the maize hypersensitive defense response have been identified with extremely high precision using association mapping in a population of 300 diverse lines each of which was genotyped by our collaborators at ~50,000 SNP loci.
We created two maize chromosome segment substitution line populations of 300 lines each, designed specifically for the identification of disease resistance loci. Each line within a population shares a common genetic background that is susceptible to multiple diseases, carries a different genomic segment bred in from a more resistant variety. This will allow us to test the effect of small genomic substitutions on multiple disease resistance, as a way to locate resistance genes.
We have used RNA-seq technology to define a set of 8000 genes that are significantly up or down-regulated during the maize hypersensitive response.
Previously we identified several loci from teosinte, the wild progenitor of maize, which were associated with resistance to southern leaf blight and gray leaf spot. We have now produced populations segregating for these loci and using these populations in two cases have successfully verified their effects.
Hung, H., Browne, C.J., Guill, K.E., Coles, N., Eller, M., Garcia, A., Lepak, N.K., Melia-Hancock, S., Oropeza-Rosas, M., Salvo, S., Upadyayula, N., Buckler IV, E.S., Flint Garcia, S.A., Mcmullen, M.D., Rocheford, T., Holland, J.B. 2012. The relationship between parental genetic or phenotypic divergence and progeny variation in the maize nested association mapping population. Heredity. 108:490-499.
Holland, J.B., Coles, N.D. 2011. QTL controlling masculinization of ear tips in a maize (Zea mays L.) intraspecific cross. Genes, Genomes, and Genomics. 1:337-341.
Hung, H., Shannon, L.M., Tian, F., Bradbury, P., Chen, C., Flint Garcia, S.A., McMullen, M.D., Ware, D., Buckler IV, E.S., Doebley, J.F., Holland, J.B. 2012. ZmCCT and the genetic basis of day-length adaptation underlying the postdomestication spread of maize. Proceedings of the National Academy of Sciences. 109:E1913–E1921.
Avendano-Lopez, A., Sanchez-Gonzales, J., Ruiz-Corral, J., De La Cruz-Larios, L., Santacruz-Rubalcava, F., Sanchez Hernandez, C., Holland, J.B. 2011. Seed dormancy in Mexican teosinte. Crop Science. 51:2056-2066.
Sanchez-Gonzales, J.J., De La Cruz, L., Vidal, V.A., Parra, R.J., Taba, S., Santacruz, F., Sood, S., Holland, J.B., Ruiz, J.A., Carvajal, S., Aragon, F., Chavez, V.H., Morales, M.M., Barba, R. 2011. Three New Teosintes (Zea spp., Poaceae) From Mexico. American Journal of Botany. 98:1537-1548.
Chia, J., Song, C., Bradbury, P., Costich, D., De Leon, N., Doebley, J., Elshire, R., Gaut, B., Geller, L., Glaubitz, J., Gore, M.A., Guill, K., Holland, J., Hufford, M., Lai, J., Li, M., Liu, X., Lu, Y., McCombie, R., Nelson, R., Poland, J.A., Prasanna, B., Phyajarvi, T., Rong, T., Sekhon, R., Sun, Q., Tenaillon, M., Tian, F., Wang, J., Xu, X., Zhang, Z., Kaeppler, S.M., Ross-Ibarra, J., McMullen, M.D., Buckler IV, E.S., Zhang, G., Xu, Y., Ware, D. 2012. Maize HapMap2 identifies extant variation from a genome in flux. Nature Genetics. 40:803-807. DOI: 10.1038/ng.2313.
Brown, P.J., Upadyayula, N., Mahone, G.S., Tian, F., Bradbury, P., Myles, S., Holland, J.B., Flint Garcia, S.A., McMullen, M.D., Buckler IV, E.S., Rocheford, T.R. 2011. Distinct genetic architectures for male and female inflorescence traits of maize. PLoS Genetics. 7(11):e1002383.
Bloom, J.C., Holland, J.B. 2012. Genomic localization of the maize cross-incompatibility gene, Gametophyte factor 1 (ga1). Maydica. 56:1782.
Blecher, A., Zwonitzer, J., Santa Cruz, J., Krakowsky, M.D., Chung, C., Nelson, R., Arellano, C., Balint Kurti, P.J. 2011. Analysis of quantitative disease resistance to southern leaf blight and of multiple disease resistance in maize, using near-isogenic lines. Theoretical and Applied Genetics. 124:433-445.
Balint Kurti, P.J., Stapleton, A. 2011. Application of an antibiotic resets the maize leaf phyllosphere community and increases resistance to southern leaf blight. Acta Horticulturae. 905:57-62.
Chaikam, V., Negeri, A., Dhawan, R., Puchaka, B., Chintamanani, S., Gachomo, E.W., Zillmer, A., Doran, T., Weil, C., Balint Kurti, P.J., Johal, G. 2011. Use of Mutant-Assisted Gene Identification and Characterization (MAGIC) to identify novel genetic loci that modify the maize hypersensitive response. Theoretical and Applied Genetics. 123(6):985-997.