Relationships and inheritance of linolenic acid and seed lipoxygenases in soybean crosses designed to combine these traits

Abstract

Reinprecht, Y., Rajcan, I., Poysa, V. W., Ablett, G. R. and Pauls, K. P. 2005. Relationships and inheritance of linolenic acid and seed lipoxygenases in soybean crosses designed to combine these traits. Can. J. Plant Sci. 85: 593-602. To improve oxidative stability of soybean oil and reduce off-flavours, we previously developed low linolenic acid, lipoxygenase-free (LLA.3lx) soybean germplasm. The objectives of this study were to characterize the patterns of inheritance and determine the relationships between the low linolenic acid (LLA) trait derived from the lines RG10 and PI 361088B and seed lipoxygenase nulls (3lx) from a triple null line OX948 that were used to create the new LLA.3lx germplasm. Reciprocal crosses between RG10 and OX948 and between PI 361088B and OX948 were made and populations derived from them were evaluated for their fatty acid profiles and seed lipoxygenases (LX) at the F 2 , F 5 and F 6 generations. Both RG10 and PI 361088B contain a single gene that controls linolenic acid (LA) content with alleles acting in an additive manner. No significant cytoplasmic effects were observed on LA content. The LLA trait was highly heritable in both RG10 × OX948 (RO) and PI 361088B × OX948 (PO) crosses and stable in different environments (Belize and Ontario, Canada). The three seed LX were each controlled by single genes, but lipoxygenase 1 (Lx1) and lipoxygenase 2 (Lx2) were tightly linked. No significant correlations were observed between LA content and seed LX. The simple and independent inheritance of LA and seed LX in these crosses should simplify breeding for soybean cultivars that are resistant to oxidative degradation. La teneur en LA ne subit aucune influence significative du cytoplasme. Le caractère LLA se transmet très facilement dans les croisements RG10 × OX948 (RO) et PI 361088B × OX948 (PO), et reste stable dans divers milieux (Bélize, Ontario au Canada). Les trois lipoxygénases de la graine sont régulées par des gènes uniques, mais la lipoxygénase 1 (Lx1) et la lipoxygénase 2 (Lx2) sont étroitement associées. Les auteurs n'ont observé aucune corrélation significative entre la teneur en LA et les LX de la graine. L'héritabilité simple et indépendante des deux caractères dans les croisements devrait simplifier l'hybridation de cultivars résistants à la dégradation par l'oxydation.

Molecular basis of the low linolenic acid trait in soybean EMS mutant line RG10

“…(1998). However, in a cross between RG10 and a wild‐type line OX948 evidence for minor genes interacting with the major gene was observed (Reinprecht et al. 2005).…”

“…OX948 was developed at Agriculture and Agri‐Food Canada, Greenhouse and Processing Crops Research Centre, Harrow, (R. I. Buzzell, unpublished data) as a seed lipoxygenase triple null mutant line (normal linolenic acid). RG10 and OX948 were crossed to produce a recombinant inbred line (RIL) population to map linolenic acid and lipoxygenase genes and to develop novel lines with improved oxidative stability (triple seed lipoxygenase nulls and low linolenic acid levels; Reinprecht et al. 2005, 2006a).…”

Agronomic performance of soybean with seed lipoxygenase nulls and low linolenic acid content

“…It is conceivable that a larger population of LLA.3lx lines would contain some higher yielding lines. It has been demonstrated previously that the LLA and 3lx are independently and simply inherited in the new germplasm (Reinprecht et al 2005) and in a RO mapping study no linkage and correlation between LA, LX and yield were detected (Reinprecht et al unpublished data). Moreover, the current population study showed that the LLA.3lx and HLA.3LX lines were very similar.…”

“…The consistently low content of LA (< 30 g kg -1 ) and the absence of seed LX in the LLA.3lx lines tested in different environments (Reinprecht et al 2005) suggests that this novel germplasm may be useful for developing soybean cultivars resistant to oxidative degradation. The 12% lower yield of the six LLA.3lx lines compared with the parental lines may be a real limitation of the unique combination of LLA and 3lx or may reflect the fact that a relatively small number (6) of genotypes with the combined LLA and 3lx traits were tested.…”

“…Previously, we combined LLA trait from a soybean line RG10 and seed 3lx trait from a line OX948 (Reinprecht et al 2005). The objective of this study was to evaluate the agronomic performance of RIL populations developed from reciprocal crosses between these two lines and LLA.3lx lines selected from these populations.…”