In 2003, eight field studies were designed to address several aspects of the silage breeding and genetics program.
The third cycle of selection in the WQS breeding population involves testcrosses of S2 families from WQS C2 with the inbred tester HC33, and these appear in trial WQS. We have also initiated the development of a complementary breeding population from the Stiff Stalk heterotic group by using a promising GEM population CUBA164:S1517 and related materials. The testcross of S2 families from CUBA164:S1517 with LH279 appear in trial CUBA.
The Germplasm Enhancement of Maize (GEM) program has also provided our program with promising breeding populations from Latin America. GEM lines appear in two of our trials, GEMA and GEMB. GEMB also includes a number of the most promising hybrids developed from the WQS breeding program.
We also are continuing research involving a series of inbred lines with different starch and endosperm characteristics that are likely to be related to starch granule packing and ruminal starch degradation. The range of endosperm characteristics extend from the o2 types with very loosely packed starch granules to densely packed flint types. We will evaluate kernel hardness, grain density, vitreousness, and related traits.
The WQSVITA-C and CUBAVITA-C trials were designed to evaluate of relationships between WQS S2 topcrosses (both open-pollinated and self-pollinated) and S2 inbred lines from which they were derived for kernel and starch properties. The information from these trials will help us determine if or when to evaluate kernel properties that may influence starch degradability.
The CIMSEL trials involves and evaluation of two CIMMYT pools, P390 MIRT and P590, selected for borer resistance. We will measure NDF, IVTD, NDFD, and other quality traits in order to determine if selection for insect resistance in these pools has influenced nutritional quality for ruminants.
Most of the trials also included numerous checks and experimental germplasm used by the silage breeding program and the UW Corn Extension Program program directed by J.G. Lauer.
| Trial | Description |
|---|---|
| WQS | Evaluation of 226 S2 families from WQS C2 topcrossed to HC33. (See yield and quality summaries – XLS format). |
| CUBA | Evaluation of 169 S2+ families from CUBA164:S1517, CUBA164:S15, and CUBA117:S1520 topcrossed to LH279. (See yield and quality summaries – XLS format). |
| GEMA | Evaluation 31 promising GEM lines crossed to LH185, LH198, HC33, or LH283. (See yield and quality summaries – XLS format). |
| GEMB | Evaluation of 55 S1+ families from the GEM program as well as advanced lines from WQS and other breeding populations topcrossed to HC33 and LH198. (See yield and quality summaries – XLS format). |
| STARCH (XLS) | Evaluation of 19 hybrids with varying kernel characteristics (formed by crossing GEM lines with varying starch properties, flint inbreds, and several checks). These were evaluated at multiple harvest periods for several grain characteristics related to ruminal digestion. |
| WQSVITA-C (XLS) | Evaluation of relationships between WQS S2 topcrosses (both open-pollinated and self-pollinated) and S2 inbred lines from which they were derived for kernel and starch properties. |
| CUBAVITA-C (XLS) | Evaluation of relationships between CUBA164:S1517 S2 topcrosses (both open-pollinated and self-pollinated) and the S2 inbred lines from which they were derived for kernel and starch properties. |
| CIMSEL (XLS) | Evaluation of two CIMMYT pools, P390 MIRT and P590, selected for borer resistance for five and six cycles, respectively. Evaluation involved analysis of NDF, ADF, lignin, and ash. Stover digiestibility evaluated after the 2004 trial is completed. |