Inheritance of Low Linolenic Acid Content in Zero-Erucic Acid Ethiopian Mustard

Zero-erucic acid Ethiopian mustard (Brassica carinata A. Braun) seed oil has very high linolenic acid content (210 g kg(-1)), which confers low oxidative stability to the oil. The line AB4 with low linolenic acid content (<30 g kg(-1)) has been developed. The objective of this research was to study the inheritance of low linolenic acid content in AB4. Plants of AB4 were reciprocally crossed with plants of the line 25X-1, with wildtype linolenic acid content. A genetic study was conducted through the analysis of the fatty acid profile of F-1, F-2, and F-3 seed generations. Low linolenic acid content in AB4 seeds was partially recessive and not subject to maternal nor to cytoplasmic effects. F-2 seeds segregated following a 1:63 (<17:>23 g kg(-1)) ratio, which suggested segregation of alleles at three independent loci. The three-gene model was confirmed in the analysis of linolenic acid content in F-2:3 families. Nine out of 341 F-2:3 families had stable low linolenic acid content, which fitted the 1:63 ratio observed in the F-2. Additionally, 1:2:1 (<8:12-33:>35 g kg(-1)), 1:4:11 (<8:25 - 40:>43 g kg(-1)), and 1:6:57 (<7:27 - 43:>47 g kg(-1)) segregation ratios were identified in F-2:3 families, which confirmed a genetic model of three independent loci with additive effects for low linolenic acid content in the Ethiopian mustard line AB4.