2013 Annual Report
1a.Objectives (from AD-416):
Evaluate GEM breeding crosses and develop germplasm for abiotic (drought and heat) and biotic stress (CEW and aflatoxin) tolerance; select, advance and release inbred lines from breeding crosses containing GEM germplasm.
1b.Approach (from AD-416):
GEM germplasm will be evaluated for abiotic and biotic stress tolerance under controlled irrigation management. Top crosses will be made with the most tolerant inbreds and yield trials conducted. Evaluation will be conducted for CEW, and aflatoxin level, and the most resistant sources advanced by inbreeding. New exotic breeding crosses will be evaluated to identify and prioritize for future breeding under abiotic and biotic stress conditions.
This is the final report which terminated 4/30/2013. The specific objectives of this project include selection and development of inbred lines with abiotic stress resistance including drought, heat, corn ear worm (CEW) resistance, and the evaluation of new breeding crosses. For the first objective approximately 100 testcrosses between GEM lines (developed in Lubbock) were evaluated for the past four years for grain yield, CEW, and drought tolerance at three locations in the Texas High Plains. Inbred lines were developed from fourteen GEM breeding crosses that included ANTIG01:N16, AR03056:N0902, BR52051:N04, CH05015:N12, CUBA117:S15, CUBA164:S20, DK888:N11, DK888:Na08f, DKXL380:S08a, FS8A(T):N11a, GUAT209:N19, SCROGP3:N1411a, SCROGP3:N2017, and SCROG1:N1318. The brown midrib trait (BMR) is an important component for silage digestibility. GEM lines were converted to BMR by backcrossing the gene bm1 into an inbred derived from GUAT209:N19, and the gene bm3 into an inbred derived from DK888:N11. Breeding development over the past four years resulted in release of five inbreds with the BMR trait. A manuscript is in progress to be submitted to the Journal of Plant Registrations. Approximately 50-60 breeding crosses were evaluated each year for drought tolerance, CEW resistance, and agronomic performance. Breeding cross evaluation was an important component for identification of promising germplasm for further development under abiotic stress tolerance.