2013 Annual Report
1a.Objectives (from AD-416):
Evaluate and develop germplasm and scientific information that support the use of maize for silage and as a feedstock for biofuel.
1b.Approach (from AD-416):
Three approaches will be used and consist of development of the GEM Quality Synthetic (GQS) population through recurrent selection, development of superior inbreds for silage yield and nutritional attributes through pedigree breeding methods, and identification and release of germplasm with lignocellulosic ethanol potential for use as a biofeedstock. Analytical methods used include conventional silage yield trials and near infrared spectroscopy (NIRS) for silage attributes, and for ethanol measurement.
This is the final report which terminated 5/31/2013. Eight silage inbreds derived from GEM germplasm were developed and released during the past four years which have become important components of the University of Wisconsin's breeding program. This includes GEM accessions from Argentina, AR17026 and AR16026 (W605S, and W616S respectively), St. Croix, SCRO1 (W606S), Brazil, BR52051 (W607S), Chile, CH05015 (W608S), the U.S., FS8B(T) (W609S), and Cuba, CUBA164 (W610S). In addition, one inbred (W615S) was released from the GEM Quality Synthetic (GQS) cycle 0 which was developed from CUBA164 and CUBA117 intermated germplasm beginning in 2007. Briefly, GQS was initially developed by selecting 20 S2 (selfed pollinated twice) families based on a performance index (MILK2006) that includes silage yield and compositional characteristics which are predictive of milk production per acre (if consumed by dairy cows). Following additional cycles of selection, further breeding, and crossing to a tester line for progeny testing, GQS is presently at cycle two, designated GQS C2. The GQS population was developed for high biomass yield and superior compositional quality of the stiff stalk heterotic group that can be crossed to the non-stiff stalk synthetic, Wisconsin Quality Synthetic (WQS). Over the past four years, the University of Wisconsin has evaluated approximately 50 breeding sources (with multiple selections per source) for yield and compositional attributes based on assessment of neutral detergent fiber (NDF), in vitro true digestibility (IVD), in vitro NDF digestibility (IVNDFD), crude protein (CP), and starch concentration. Based on these values, and milk/ton of forage, milk/acre was estimated based on the MILK2006 equations (Schwab et al., 2003). In 2012 and 2013, five and eight additional GEM populations were introduced respectively into the breeding program. Also included were GEM waxy populations CUBA164:S2012-966 wx and DKXL370:N11a20-36 wx, which will be evaluated for silage yield and composition. Plans are to continue the breeding effort and yield trials in summer 2013. Extensive rainfall in 2013 resulted in a late planted yield trial on June 3 at West Madison, and nothing was planted at Arlington. More information about GEM derived lines can be found on http://cornbreeding.wisc.edu/inbred releases.