Fatty acid composition of resynthesized Brassica napus L., B. campestris L. and B. alboglabra Bailey with special reference to the inheritance of erucic acid content

Abstract

The fatty acid composition of the oil of four resynthesized rapeseed (Brassica napus L.) lines resulting from crosses between B. campestris L. and B. alboglabra Bailey was compared with that of the mid-parent value. Low palmitic acid content was partially epistatic over high. High oleic acid content could be either partially hypostatic to or transgressively epistatic over low content of this fatty acid, depending on the erucic acid contents of the parental species. Epistasis was observed for low linoleic acid content in two crosses whereas additive gene action was shown for this fatty acid in the other two crosses. Partial or transgressive epistasis was observed for low linolenic acid content. High eicosenoic acid content was generally epistatic over low. Partial epistasis was observed for high erucic acid content in three crosses but hypostasis was also observed in one cross. Oleic acid content played a key role in the change of fatty acid composition. Regarding the inheritance of erucic acid content, the hypothesis was substantiated that B. napus contained two genes for this fatty acid residing in the genomes from B. campestris and B. oleracea. Caution should be taken in accepting the proposed hypothesis (Krzymanski and Downey, 1969) that there is a series of erucic alleles based on the phenotypic value of erucic acid content, because the influence of different genetic backgrounds and/or ploidy level on the allelic performance is not taken into consideration.

Genetic control of fatty acid composition in seed oil of Sinapis alba L.

“…Similar conclusions have been reported for various Brassica crops (Chen & Beversdorf, 1990;Chen & Heneen, 1989) . The limited genetic variances found for linoleic and linolenic acids (Tables 1, 2 and 3) demonstrate the relatively minor effect of the alleles at the two desaturation loci, in the investigated diallel system .…”

“…In contrast, the inadequacy of the additive-dominance model for eicosenoic level (Table 3) Table 3) . A similar mode of inheritance has been reported for erucic acid in B. napus and in B. campestris by others (Chen & Heneen, 1989) .…”

“…The effect of the embryonic cytoplasm plus the non-genetic (maternal) effect of the mother plant were of minor importance (Table 3) . Prevailing embryogenic control of oleic and erucic acid content was found in rapeseed and in its diploid relatives (Chen & Heneen, 1989;Robbelen & Thies, 1980) . The adequacy of the additive-dominance model proved highly significant for oleic, linoleic and erucic acids, therefore, it seems that other genetic effects were negligible (Table 3) .…”

“…Heterotic eicosenoic level was also demonstrated by resynthesized B. napus lines (Chen & Heneen, 1989 (Fehling & Mukherjee, 1990 ;Harwood, 1989 ;Kunst et al ., 1992) . Additionally, oleic acid can go through two successive desaturation steps, 18 :1 to 18 :2 and 18:2 to 18 :3, each probably controlled by different loci (Stymne et al ., 1987) .…”

Interspecific cross of Brassica oleracea var. alboglabra and B. napus: effects of growth condition and silique age on the efficiency of hybrid production, and inheritance of erucic acid in the self-pollinated backcross generation

“…Taking the dose eVect of the erucic acid alleles into account, nine seed genotypes would be possible in BC 1 S 1 with respect to erucic acid alleles (Table 3). The phenotypes of these genotypes could be inferred based on the reports of earlier researchers (Chen et al 1988;Rahman 2002; Table 3). …”