Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: July 15, 2010
Publication Date: September 18, 2010
Citation: Tomasi, P., Dierig, D.A., Dyer, J.M., Coffelt, T.A. (2010). An interspecific BC2 Lesquerella hybrid yield trial. 22nd Annual Meeting of the Association for the Advancement of Industrial Crops, September 18 - 22, 2010, Fort Collins, CO, p. 14. Technical Abstract: Lesquerella [L.fendleri (A. Gray) S. Watson] is a domestic oilseed source of hydroxy fatty acids (HFAs) that could be grown on thousands of acres in the arid southwestern USA. The oil from lesquerella is similar to castor oil and can be used in lubricants, greases, coatings, and as an additive to biodiesel to improve lubricity. Increased yields of seed, oil content, and hydroxy fatty acid content are needed to successfully commercialize lesquerella. Wild relatives of L. fendleri, such as L. pallida, have lesquerolic acid contents up to 85% compared to 55% from L. fendleri, indicating that enzymes must be present to selectively incorporate the fatty acid at the sn-2 position of triacylglycerol. Hybrids between the two species thus could potentially increase the HFA content of L. fendleri from the current levels. The objective of this study was to evaluate six yield and six oil traits of an improved lesquerella germplasm line, WCL-LO3 (Reg. no. GP-33, PI 642047) compared with four interspecific BC2 generation hybrid lines of L. fendleri x L. pallida. The five lines were planted in a randomized complete block of three replications during the 2007-08 lesquerella growing season. Silique subsamples were analyzed from 68 plants to determine the mean values of seed per silique, sound seed weight, and total seed weight per silique. Plant dry weight and total seed weight were used to determine percent seed produced from 74 harvested plants. Seventy one plants produced enough seed for half gram NMR total oil percent analysis. Ten single seed subsamples from each of 74 harvested plants were analyzed for fatty acid composition on a HP 6890 gas chromatograph. The means of the four hybrid lines compared to the control line WCL-LO3 were not significantly different either as a group or individually for five of the six yield traits (seed per silique, total seed weight/silque, plant dry weight, total seed weight, and percent seed). As a group the hybrids were significantly heavier (0.667 g/1000 seed) than WCL-LO3 (0.573 g/1000 seed). The total oil for the group of hybrid lines (22.95%) was significantly less (P<0.05) than that of the WCL-LO3 (28.67%). In contrast the percentage of linolenic acid was significantly higher (P<0.05) for the hybrids (11.65%) than for WC-LO3 (11.04%). No significant differences were found between the hybrid lines and WC-LO3 for the percentage of the other fatty acids evaluated (oleic, linoleic, lesquerolic, and auricolic). Twenty six of the hybrid plants expressed varying yellow seed color characteristics. Utilization of an interspecific backcross/selection method is a conventional breeding strategy that may introgress desirable yield traits from L. pallida to L. fendleri.