| Oleic acid is monounsaturated fatty acid, which is one kind of essential components of rapeseed fatty acids. It has high nutrition value and can be easily absorbed and digested. It was reported that high oleic acid content (> 75%) of rapeseed oil has huge using value as the cooking oil and in industry. But the oleic acid content in the normal rapeseed oil is 40%-60%; so it is one of the most important aims of rapeseed quality improvement to increase the content of oleic acid.This study applied six generations high-oleic acid materials and two normal materials (middle oleic acid lines) as male and female parents each other to design the oleic acid 8×8 complete diallel.The research result will provide some basis evidences for high oleic acid breeding by preliminarily analyzing the inheritance mechanism of high-oleic acid in Brassica napus mutant materials. Main contents and results are as follows:1. The fatty acids components of B.napus L. were analyzed by applying 8×8 complete diallel cross and GGE biplot. The results showed that:(1) As paternal, Y511 and Y539 had higher general combining ability (GCA) than other paternals, L308, Y511 and Y539 had higher specific combining ability (SCA). As female parent, Y511, Y520 and Y539 had higher GCA, and L121, L307, L331 and Y539 had higher SCA.Y511,Y520,Y539 and L307,L331,Y539 had higher combining ability, L121 and L308 owned the lowest combining ability; (2) Y539 was the optimum paternal for L121,L307,L308,L332,Y511,Y520,Y539 as well as Y511 for L331.Y520 was the optimum female parent with L121,L307,L331,L332,Y511, as well as Y539 with L308,Y520,Y539; (3) It had higher SGA of L307×L308, L331×L332, L332×Y511, Y520×Y511, Y539×L121; (4) When erucic acid (C22:1) content was zero, carbon acid (C20:1) content was around 0.87% and stearic acid (C18:0) content was 1.36%-1.75%, the paternal GCA of palmitic acid (C16:0), linoleic acid (C18:2) and linolenic acid (C18:3) were negative correlated with the GCA of oleic acid (C18:). As female parents, the GCA of stearic acid was positively correlated with the GCA of oleic acid and palmitic acid, linoleic acid, but linolenic acid were negatively correlated; (5) According to fatty acids in the hybrid phenotype relationship:stearic acid was positively correlated with oleic acid, palmitic acid was negatively correlatedwith oleic acid, linoleic acid and linolenic acid were significantly negatively correlated with oleic acid. These results were consistent with the relations between fatty acids components of female parent.2. Applying plant quantitative traits of major gene plus polygenes mixed inheritance model, to six generations (P1, F1, P2, B1,B2 and F2) from the high oleic acid lines Y539 and middle oleic acid lines L121 of Brassica napus were analyzed by joint analysis of multi-generations. The results indicated that:The oleic acid content of Y539 x L121 was controlled by 2 additive-dominance-epistasis major genes with additive-dominance-epistatic multiple genes, and dominantly affected by major genes, whereas affected by the environment. The highest major gene heritability of oleic acid content of the crosses is B1 which is 80.11%, B2 is 59.54%, and F2 is the lowest, only 48.04%; F2 had the highest heritability of multiple genes, which is 35.28%; B2 is 15.63% and B1 is 0. In this study, the environment contributed to the content of oleic acid, for its variance holded 16.68-24.83% of the total. The two major genes had equal additive effect, which indicated that these two genes owned the same cumulative effect. The dominance effects of two genes were also significant; for the No.1 main gene, | ha/da│> 1, sign of over dominance; for the No.2 main gene,0<| ha/da|<1, which denoted partial dominance.In epistasis effect, the dominance×dominance effects (1) and the interaction effect of additive of no.2 major genex the dominant of no.1 major gene (jba) is significantly obvious. In this study, ha< 0, hb< 0, this results showed that the low oleic acid content of rapeseed was partial dominant to high levels.3. In this study, cross-validation correlation coefficient (1-VR) of Near Infrared Spectroscopy of oleic acid model was 0.9205. Cross-test standard deviation (SECV) was 1.5264. The external validation correlation coefficient (RSQ) was 0.9300. Standard deviation of the external validation (SEP) was 1.4510 to test deviation was 0.0440. It indicated that the model had good accuracy and predictive power of analysis. It can be used for rapidly screening early material of high oleic acid breeding. In other fatty acids content models, almitic acid, linoleic acid and linolenic acid model had better internal cross-examination,1-VR were 0.8192,0.8050 and 0.8820, respectively; SECV 0.1814,1.8159 and 0.6234, respectively, RSQ were over 0.8220,0.8850 and 0.8170, respectively; SEP were 1.6180,0.6270 and 0.1950, respectively, test deviations were-0.1310,-0.0410 and 0.0120,respectively. It indicated that the models reached a relatively satisfactory result, and can be applied in practical breeding. |
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