|Mccouch, Susan - Cornell University - New York|
Submitted to: Plant and Animal Genome Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 11/6/2015
Publication Date: 1/9/2016
Citation: Edwards, J., Eizenga, G.C., Yeater, K.M., McCouch, S.R., McClung, A.M. 2016. Transgressive variation for yield components and dynamic traits in Jefferson (Oryza sativa) x O. rufipogon introgression lines. Plant and Animal Genome Conference Proceedings. W012.
Technical Abstract: Alleles from wild progenitors of crops can be a source of transgressive variation in modern cultivars. Introgressions from the Oryza rufipogon donor (IRGC104591) in an O. sativa tropical japonica cultivar (Jefferson) were shown to confer a yield advantage in multi-location field trials. Yield loci were mapped in an advanced backcross population, and subsequently introgression lines (ILs) were developed by backcrossing and molecular selection to capture six promising yield loci. Field studies showed that these ILs have retained the expected yield advantage. To make effective use of the wild alleles and associated transgressive yield increases in breeding programs, it is useful to identify the specific yield components affected in each of the ILs. In the current study, the ILs were evaluated under controlled greenhouse conditions with the objective of determining the effects on yield component traits, the relationships between traits, and the changes in the effects throughout the life cycle. Dynamic traits were assessed by fitting a logistic model to measurements over time. To estimate above ground biomass, a novel image analysis pipeline was developed. Relative to Jefferson, the ILs were slower to develop and produced more biomass. At maturity ILs carrying yield loci were significantly different from Jefferson for: longer flag leaves and panicles (yld1.1, yld2.1, yld3.2, yld8.1, yld9.1), increased panicle branch number (yld6.1, yld9.1), and more seed per panicle (yld2.1, yld6.1, yld8.1). These results support a model of transgressive variation where alleles from an agronomically inferior wild donor increase yield by contributing to variation in growth and yield components.