GENETICS OF MULTIPLE DISEASE RESISTANCE IN MAIZE INBRED NY22613 AND SCIENCE COMMUNICATION OF QUANTITATIVE GENETICS
Given unpredictable pathogen pressures caused by changing climatic patterns, plant breeders aim to breed crop varieties with durable resistance to multiple plant pathogens. Understanding the genetic basis of multiple disease resistance will aid in this endeavor. Maize inbred NY22613, developed at Cornell University, have shown resistance to northern leaf blight (NLB), gray leaf spot (GLS), common rust, and Stewart’s wilt (SW). A BC3S3 bi-parental mapping population (resistant inbred NY22613 and susceptible inbred Oh7B) was used to map the QTLs responsible for disease resistance. The analysis revealed that 16 quantitative trait loci (QTL) were associated with NLB resistance, 17 QTL with GLS resistance and 16 QTL with SW resistance. No QTL were colocalized for all three diseases. Three QTL were shared for NLB and GLS and one QTL was shared for GLS and SW. To select individuals with multiple disease resistance, we demonstrated a selection method that uses phenotypic data, QTL data and high density marker information in a cluster analysis, designated the high density marker phenotype (HEMP) QTL selection strategy. A differential expression study was conducted using susceptible inbred Oh7B and resistant inbred NY22613 in both field and greenhouse conditions, to identify genes that are differentially expressed when inoculated with Setosphaeria turcica (NLB). The Zm00001d024772 gene (unknown function in maize) was differentially expressed between the uninoculated and inoculated Oh7B in field and greenhouse conditions. Zm00001d027691, Zm00001d011152, Zm00001d008951, Zm00001d033623, Zm00001d021770 and Zm00001d034421 were differentially expressed in response to NLB inoculation in NY22613 in field and greenhouse conditions. None have a previously known function in maize, but Zm00001d033623 plays a major role in rice disease immunity. QTL analyses implicates liguleless1 to be associated with disease resistance to GLS and SW and the differential expression study implicates liguleless1 gene to be associated with disease resistance for NLB. This suggests that liguleless1 is an important candidate gene for multiple disease resistance. Direct-to-consumer genetic testing companies conduct low cost genotyping and genome sequencing for humans. This has led to the public having access to their genomic data more than ever before. Quantitative genetics is essential to understand genomic data. Science communication of quantitative genetics to the public is an under-explored strategy to address this issue. The story of quantitative genetics in humans is ugly due to its eugenic origins, however, the story of quantitative genetics in agriculture is inspiring. Using the achievements of quantitative genetics in agriculture, key concepts can be communicated to a diverse audience. Further, the quantitative genetics methods used in plant and animal breeding are being used in human genomic data. This necessitates plant and animal breeders/geneticists to participate in the communication of quantitative genetic methods to the public, so that the public can make informed decisions with their genomic data.
Supplemental file(s) description: Appendix
Maize; Quantitative Genetics; Genetics; Communication; science communication; Multiple Disease Resistance; QTL mapping; RNA Seq; Plant sciences
Smith Einarson, Margaret Elizabeth
Lewenstein, Bruce Voss; De Jong, Walter S.
Ph.D., Plant Breeding
Doctor of Philosophy
Attribution-NonCommercial-NoDerivatives 4.0 International
dissertation or thesis
Except where otherwise noted, this item's license is described as Attribution-NonCommercial-NoDerivatives 4.0 International