Project Number: 5030-21000-059-02
Start Date: Jun 27, 2014
End Date: Apr 30, 2015
Objective 1. GEM materials to be used in this study include three isogenic lines of waxy GEM releases: GEMS-0185, GEMN-0186, GEMS-0206, and in addition their three corresponding normal (non-waxy) counterparts. Two F1 waxy hybrids (GEMS-0185 × GEMN-0186 and GEMS-0203 × GEMN-0186) and their normal counterparts will be studied which include six hybrids; waxy × waxy, waxy × normal, and normal × normal for each of the two F1 pedigrees. Yield trials will be planted at four locations, and in the GEM nursery and hand pollinated for starch analysis. The dosage effects of waxy gene will be studied using an enzymatic method for total-starch content. Starch will be isolated from kernels and physical properties analyzed which include gelatinization, retrogradation rate, swelling power of starch granules, pasting properties, and enzyme digestive rates. Dosage effects of waxy gene on the structure and properties of the starch will be determined. The hand pollinated grain (F2 generation seed) of waxy × waxy, waxy × normal, and normal × normal will be subjected for ethanol production studies in the lab to evaluate the dosage effect of waxy gene on ethanol yield. Objective 2. High-amylose popcorn hybrids have been developed using GEMS-0067 × three popcorn public inbreds; GEMS-0067 × Sg1533, GEMS-0067 × Hp301, and GEMS-0067 × Hp72-11. Comparison will be made with B73 crossed to the same popcorn inbreds. Starch of the six hybrids will be isolated and subjected to structural analyses to determine the amylose content and amylopectin structure. The isolated starch will be analyzed for gelatinization properties and enzyme digestibility. The high-amylose popcorn will be subjected to popping tests to determine the effect of high amylose-content on the popping ability. After popping, the high-amylose popcorn will be sampled for sensory evaluations to find consumer acceptance of the product as a healthy alternative for traditional popcorn. High-amylose × high-oil germplasm have been developed using two GEM lines; GEMN-0131, and a 50% tropical inbred derived from CUBA164:S15. The two lines were crossed to a high-amylose inbred line from Truman State University designated Truman 40. The hybrid corn will be analyzed for the starch, oil, and protein contents. Starch of the hybrid corn and the parent lines will be isolated and subjected to structural and property analyses. The amylose and lipid contents of the starch will be analyzed, and correlations between the lipid content of the starch and oil content of the kernels will be determined. Thermal properties of the starch, swelling power, and pasting properties of isolated starch will be determined and correlated with the lipid content. Enzyme digestibility of isolated starch and starch in dry-grind corn will be analyzed, and the effects of lipid contents on the starch digestibility will be evaluated.