A healthy diet requires a shift from the consumption of highly refined and processed foods with low nutritional value and towards whole grain food that have increased levels of antioxidants and phenolic compounds. Certain specialty sorghum genotypes have been identified as potential whole grain foods that have high levels of desired chemical compounds. Specifically, sorghums with a black pericarp are excellent sources of antioxidant compounds, including the unique compound 3-deoxyanthocyanin (3-DOA). Although extensive work has been performed on the chemistry and food properties of black sorghum inbreds, little research has been done studying the grain phenolic composition and agronomic performance of black sorghum hybrids in production environments. The goal of this study was to evaluate black sorghum hybrids with differing genetic backgrounds for grain phenolic composition and agronomic performance across multiple environments and identify the best lines for producing these hybrids. Results from this study confirm that sorghums with a black pericarp contain elevated levels of phenols, tannins and 3-DOA. Concentrations of these beneficial compounds were many times the concentration levels seen in traditional grain hybrids. Grain yields of black sorghum hybrids averaged 36% below commercial hybrids in this study. Lower grain yields could be due to reduced heterosis in black sorghum hybrids and other unknown factors associated with the black phenotype. From this study, the Texas AgriLife Sorghum Breeding Program has developed two elite black sorghum lines for release as the first publicly available black pericarp seed parents. These newly developed seed parents, proposed for release as Tx3363 and Tx3364, allow for the creation of the first temperately adapted black seeded grain hybrid. These hybrids help address the growing demand for products that are healthy, and provide natural and stable antioxidant compounds for a growing health food industry.

Thesis (Ph.D.)--Cornell University, August, 2008. / Includes bibliographical references.

Typescript, etc. / Digitized by Kansas State University Libraries

No description available.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1994. / Vita. Abstract. Includes bibliographical references (leaves 56-62). Also available via the Internet.

Thesis (Ph.D.) - University of Queensland, 2005. / Includes bibliography.

This study evaluated relative responses of two grain sorghum (Sorghum bicolor (L.) Moench) hybrids to moisture stress treatments imposed during the seedling, early boot, flowering and grain-filling stages. The two hybrids, T.E. Y77 and FUNK HW6125, are high and low yielding respectively, having similar maturity periods. Twelve phenological characters were measured. The height to upper leaf collar, peduncle exsertion, panicle length, total plant height and total leaf area showed significant differences between the hybrids. Early boot stage stress was most sensitive to vegetative characters. T.E. Y77 produced more heads/m², grains, panicle, 500 grain weight (seed size), and grain yield/ha than FUNK HW 6125 across all treatments. Seed size was the most important determinant of grain yield in both hybrids. Moisture stress during the seedling and early boot stages enhanced grain yield, whereas during the grain-filling stage it was detrimental to grain yield in both hybrids.

In sorghum, a single recessive gene Wx conditions waxy endosperm type. While parental inbred lines and hybrids with waxy endosperm have been developed, there has been little to no adoption of these hybrids by producers, primarily because waxy hybrids consistently yield 5-10% less than non-waxy hybrids and end-use buyers will not pay for the utilization benefits. While current waxy germplasm does not yield competitively at this time, there is a question as to whether the yield reduction is due to a negative relationship between waxy per se or due to the lack of effort to develop high yielding waxy germplasm. The purpose of this study is to determine the relationship between the waxy endosperm phenotype and grain yield in sorghum. From each of two F2 breeding populations segregating for waxy endosperm, 50 inbred lines were derived, selected only for homozygosity of endosperm type. No selection for yield was practiced during the development of these lines. Approximately 25 waxy and 25 non-waxy lines were selected for further evaluation from each population. These lines and a set of testcross hybrids were evaluated in four environments. When combined across environments and populations, waxy inbred lines and hybrids yielded 17% less than non-waxy inbred lines and hybrids. However, analysis of the individual inbred lines and hybrids indicated that several waxy inbred lines were competitive in yield with the best non-waxy genotypes. The results indicate that it should be possible to develop waxy hybrids that are competitive in yield, but that this will require additional breeding efforts to identify the correct inbred lines and hybrids.

In sorghum, a single recessive gene Wx conditions waxy endosperm type. While parental inbred lines and hybrids with waxy endosperm have been developed, there has been little to no adoption of these hybrids by producers, primarily because waxy hybrids consistently yield 5-10% less than non-waxy hybrids and end-use buyers will not pay for the utilization benefits. While current waxy germplasm does not yield competitively at this time, there is a question as to whether the yield reduction is due to a negative relationship between waxy per se or due to the lack of effort to develop high yielding waxy germplasm. The purpose of this study is to determine the relationship between the waxy endosperm phenotype and grain yield in sorghum. From each of two F2 breeding populations segregating for waxy endosperm, 50 inbred lines were derived, selected only for homozygosity of endosperm type. No selection for yield was practiced during the development of these lines. Approximately 25 waxy and 25 non-waxy lines were selected for further evaluation from each population. These lines and a set of testcross hybrids were evaluated in four environments. When combined across environments and populations, waxy inbred lines and hybrids yielded 17% less than non-waxy inbred lines and hybrids. However, analysis of the individual inbred lines and hybrids indicated that several waxy inbred lines were competitive in yield with the best non-waxy genotypes. The results indicate that it should be possible to develop waxy hybrids that are competitive in yield, but that this will require additional breeding efforts to identify the correct inbred lines and hybrids.

Thesis (Ph. D.)--Wageningen University, 2003. / Thesis propositions sheet inserted. Includes bibliographical references (p. 183-185).