Salvia is a genetically diverse genus in the Lamiaceae family, with hundreds of species distributed globally. With base chromosome numbers ranging from 6 to 19 and ploidy levels ranging from diploid to octoploid, the genus has been proposed to be subdivided based on molecular data rather than morphology. However, little is known about total DNA content across the genus. The DNA content of 141 Salvia genotypes were analyzed using flow cytometry. Samples of Salvia were stained with propidium iodide and compared with the internal standards Pisum sativum ‘Ctirad’ and Solanum lycopersicum ‘Stupické’ to generate estimations of DNA content. Holoploid 2C genome sizes of the analyzed Salvia ranged from 0.63 pg to 6.12 pg. DNA content showed a wide distribution across chromosome number, ploidy, and clade. The wide distribution of DNA content across the genus further indicates the diversity of Salvia and may be useful for future breeding efforts.

We documented a successful embryo rescue (ER) protocol for butterfly weed (Asclepias tuberosa), a member of the milkweed family (Asclepiadaceae). Milkweed (Asclepias sp.) includes more than 100 species native to the United States, is an important pollinator plant, and has many commercially desirable traits. However, there is little commercial production outside of native plant nurseries because milkweed species are typically seed-grown and suffer from low seed set during pollination, late-term abortion of seed pods, and nonuniform germination. This project determined the optimal growing media (study one) and embryo maturity (study two) to recover mature seedlings from excised embryos and compared the results to those of traditional methods of seed germination (in soilless substrate). Study one investigated three different media: Murashige and Skoog (MS) medium at full strength and half strength and woody plant medium. MS medium at half strength was optimal for butterfly weed germination and maturation, with greater root and shoot lengths at the time of harvest. In study two, the effects of MS medium at half strength on embryo maturation 90, 60, and 30 days after pollination (DAP) were investigated. The optimal time to harvest embryos was 60 DAP; embryos at 30 DAP were capable of germination but not maturation. A mean germination rate of 97.4% was observed when using embryo rescue, but it was 72.3% with mature seed germinated in soilless substrate typical of commercial production. A similar increase in germination rates was observed for all embryo maturities when compared with seed germinated using soilless substrate. The protocol developed for this study should help to standardize production, reduce propagation time, and improve the commercial acceptance and profitability of milkweed.

Salvia coccinea is a valuable flowering annual that attracts hummingbirds and bees to the garden, but few cultivars are commercially available. There is a limited range of petal colors and no leaf variegation. This research aimed to improve the ornamental value of S. coccinea by inducing mutations with ethyl methanesulfonate (EMS). The standard, red-flowered species was selected for treatment by exposing seeds to 0%, 0.4%, 0.8%, or 1.2% EMS for 8, 12, or 24 hours. The optimal treatment rate was determined to be 1.2% EMS for 8 hours, which generated desirable mutations near the median lethal dose (LD50). The M1 population had a 53% germination rate and was completely morphologically uniform. By the M2, mutations included differences in leaf shape and flower size in addition to albina, chlorina, virescens, and chimeral chlorophyll changes. A 1% mutation rate was achieved in this breeding program with seven unstable mutations and six stable mutations. The normalized difference vegetation index (NDVI) values were measured to determine differences in chlorophyll content between lethal albina mutations, chartreuse chlorina and virescens mutations, and typical leaf color. Future work will investigate the stability and heritability of chlorophyll variegation by hybridizing these selections with coral-flowered accessions of S. coccinea.

Salvia is the largest genus in the Lamiaceae with more than 1000 species. The species S. coccinea used in this study has naturalized in the southeastern United States and is an important plant for pollinators. This project aimed to improve phenotypic characteristics of S. coccinea for use in the landscape by selecting for increased petal size and unique petal color. Two elite accessions were selected for hybridization using the pedigree method. One selection displayed compact habit with bicolored coral and white flowers, while the other was slightly larger with solid red flowers. Selections were made based on improved flower color and larger petal size. The breeding program achieved a 25% increase in petal width and a more vivid petal color for the coral bicolored selections. Additionally, a 60% increase in petal width was achieved for red flowers. These novel selections are attractive plants for the landscape, displaying improved ornamental value and supporting local pollinator populations.