Development of an efficient sea oats breeding program for coastal restoration

Uniola paniculata (sea oats) has been used extensively to build artificial dunes as well as stabilize existing dunes along the southern Atlantic and Gulf of Mexico coasts of United States. A breeding program could enhance coastal restoration by developing improved plants for beach restoration. Our goal was to initiate a successful breeding program for sea oats adapted to low dune profiles, with high seed yield and germination, and superior vegetative biomass essential for reducing coastal erosion. The specific objectives were to: 1) examine effect of storage environment on sea oats seed germination; 2) determine time necessary for sea oats seeds to germinate; 3) determine sea oats seed moisture content; 4) determine pathogen incidence during germination; 5) determine survival and performance of vegetative sea oats plants and sea oats seedlings at beach environments with shallow dune profiles; 6) develop efficient methods to identify saturation tolerant sea oats lines; 7) determine sea oats seed yield in natural and artificial environments and 8) identify fungal and bacterial pathogens of sea oats seed. Sea oats seed stored in hermetically sealed jars at room temperature had highest average germination and seed germination was highest 21 days after germination. Sea oats seed moisture content, ranged from 6 to 16 %, and was negatively correlated with germination. Small sea oats seedlings had highest mortality however, seedling cost significantly less than vegetative plants. Increasing seedling densities could reduce production costs and result in acceptable survival rates accompanied with genetic diversity. We found that small seedlings flooded continuously to 14 cm depth in greenhouse for 3 months could predict sea oats survival in saturated beach conditions after 6 months. In 2007, 2009, 2010, and 2011 we determined sea oats seed yield in natural and artificial environments. Consistent seed yields were not obtained for either environment; however, sea oats seed were produced in artificial production nurseries. Finally, to determine seed pathogens colonizing sea oats seed, bacteria and fungi were isolated from sea oats seed harvested in 2011 and identified using both morphological and molecular techniques. The dominant bacterial genera colonizing sea oats seed were Bacillus and Enterobacter; while the dominant fungal genera were Fusarium and Curvularia

Development of Perennial Grain Sorghum

Perennial germplasm derived from crosses between Sorghum bicolor and either S. halepense or S. propinquum is being developed with the goal of preventing and reversing soil degradation in the world’s grain sorghum-growing regions. Perennial grain sorghum plants produce subterranean stems known as rhizomes that sprout to form the next season’s crop. In Kansas, breeding perennial sorghum involves crossing S. bicolor cultivars or breeding lines to S. halepense or perennial S. bicolorn × S. halepense breeding lines, selecting perennial plants from F2 or subsequent populations, crossing those plants with S. bicolor, and repeating the cycle. A retrospective field trial in Kansas showed that selection and backcrossing during 2002–2009 had improved grain yields and seed weights of breeding lines. Second-season grain yields of sorghum lines regrowing from rhizomes were similar to yields in the first season. Further selection cycles have been completed since 2009. Many rhizomatous lines that cannot survive winters in Kansas are perennial at subtropical or tropical locations in North America and Africa. Grain yield in Kansas was not correlated with rhizomatousness in either Kansas or Uganda. Genomic regions affecting rhizome growth and development have been mapped, providing new breeding tools. The S. halepense gene pool may harbor many alleles useful for improving sorghum for a broad range of traits in addition to perenniality