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Germplasm development of Vernonia galamensis as a new industrial oilseed crop

Thompson, A.E., Dierig, D.A., Johnson, E.R., Dahlquist, G.H., Kleiman, R.
Industrial crops and products 1994 v.3 no.3 pp. 185
crossing, Vernonia, plant breeding, hybridization, germplasm, varieties, flowering, photoperiodism, seed set, hybrids, seed germination, seed dormancy, seed oils, long chain fatty acids, genotype-environment interaction, artificial selection, vernolate, oilseed crops
Genetic transfer of the day-neutral flowering habit found in Vernonia galamensis ssp. galamensis var. petitiana [A 20295 (V 029)] has been successfully accomplished by intraspecific hybridization. Crosses were made in 1990-1991 utilizing var. petitiana as the female parent and five other accessions from the V. galamensis complex as male parents. The F1 progenies of the crosses were grown in the greenhouse in 1991-1992. Single plant selections were made within F2 and F3 field-grown populations in 1992 and 1993, respectively, in Arizona and various locations throughout the continental United States. Seed increase of selected F3 plants was made in Puerto Rico in 1993-1994 for wide-scale evaluation, further selection, and initiation of agronomic crop production research. Selection for rapid germination in the seedling stage in F2 and F3 populations was effective in minimizing seed dormancy. Early germination, nine days after planting, increased from 10.9 ± 1.6% for the F2's, to 34.3 ± 1.8% for the F3's. Among the 59 F2 crosses grown under long-day conditions in the field in 1992, the percentage of F2 plants flowering ranged from 31% to 100%, with a mean of 77.3 ± 2.5%. Flowering percentage of F3 progenies from within 38 crosses increased to 94.2 ± 1.6% with a range of 50% to 100%. Mean seed weights of greenhouse-grown F1's was 5.73 ± 0.12 g/1000. Field-grown F2's and F3's had smaller seed weights, 2.50 ± 0.05 and 2.11 ± 0.06 g/1000, respectively. The F1's also had higher seed oil and vernolic acid contents (39.8 ± 0.4% and 80.8 ± 0.4%) as compared to the F2's (33.2 ± 0.4% and 62.0 ± 1.0%) and the F3's (32.1 ± 0.6% and 64.9 ± 0.8%). The relatively wide range in seed weight, and in oil and vernolic acid contents in both F2's and F3's demonstrate that directed selection for these yield factors should be effective. High genotype × environment interaction suggests that plant selection and evaluation should be conducted over a range of geographic and climatic conditions within the temperate zone to identify the most favorable production sites. The rapid progress made within the past five years indicates that commercialization of vernonia as a new industrial oilseed could be a reality within the next seven to ten years.