Submitted to: Euphytica
Publication Type: Peer reviewed journal
Publication Acceptance Date: 9/7/2004
Publication Date: 1/15/2004
Citation: Dierig, D.A., Tomasi, P., Salywon, A.M., Ray, D.T. 2004. Improvement in hydroxy fatty acid seed oil content and other traits from interspecific hybrids of three lesquerella species; lesquerella fendleri, l. pallida and l. lindheimeri. Euphytica 139:199-206. Interpretive Summary: We found there is not enough natural variability to improve an important oil characteristic, hydroxy fatty acids (HFA), in plants from lesquerella a species being commercialized. Much higher amounts are present in the oil of related species, even though they do not produce as much seed. The species are prevented from producing seed (they are sterile) when crossed together because of a biological barrier. Hybrids were produced between species that do not normally cross using novel methods. We found different combinations of traits that confirmed they did not occur from either crossing with another plant of the same species or with itself. There was a substantial increase in the HFA amount in the seed oil in these hybrids above the range of variability normally found. These hybrids provide a new basis for opportunities in commercialization of this potential new crop, since oil will be cheaper and products will be more profitable.
Technical Abstract: Interspecific hybridization offers potential to improve the hydroxy fatty acid (HFA) content of lesquerella. Lesquerella fendleri is currently being developed for cultivation as a potential new industrial oilseed crop because of its seed productivity. However, it has lower HFA content compared to L. pallida and L. lindheimeri. The objectives of this research were to improve the HFA oil content of L. fenderi through interspecific hybridization and to characterized hybrids and successive generations for seed oil fatty acid profile, fertility, seed set and other morphological traits. In this work, three species were successfully hybridized, self-pollinated, and backcrossed. Ovule culture was used in some cases to produce progeny where interspecific hybrids did not produce viable embryos. The traits measured were petal length, ovules per silique, seeds per silique, and weight of 1000 seed. Patterns of leaf trichomes were used to distinguish between parents and hybrids. Seed per silique indicated that autofertility occurred in L. pallida but not in the other two species. HFA oil content of L. fendleri seed were 50.5% compared to 80 and 84% for L. pallida and L. lindheimeri, respectively. The HFA oil content of the hybrids ranged from 57 to 70% in A2 and A3 generations, and the range of values depended on the parents used in the crosses. These measurements will help predict the value of different interspecific crosses for breeding. Segregation for various yield related traits should allow selection for favorable improvements in the HFA trait and in seed yield.