Variability of Fatty Acid Composition in Interspecific Hybrids of Mustard Brassica Juncea and Brassica Napus

In Sri Lanka, mustard (Brassica juncea) is cultivated as a subsidiary crop for the seeds used as a condiment in cooking. In the Indian sub-continent, however, it is an important oilseed crop used as a source of vegetable oil. Mustard has over 45% erucic acid (C22:1) which is unsuitable nutritionally for human consumption. The Brassica oilseed species, B. napus and B. campestris, were developed in Europe and Canada, known as canola, by conventional breeding methods to alter their fatty acid composition and reduce erucic acid and glucosinolates to nutritionally accepted levels for human consumption. Sri Lanka has over 60 accessions of B. juncea. In this study, the fatty acid composition of 12 accessions was determined. Erucic acid was in the range of 37 – 45%, oleic acid was low at 13.8% while the polyunsaturated linoleic and linolenic acids were 18.6% and 10.5% respectively. To alter the fatty acid composition of mustard, canola quality B. napus cultivars from W. Australia were crossed with B. juncea accessions. Only crosses with canola as the male parent set seeds. The crossability (podset per 100 pollinations) was dependent on the genotype of the canola parent. Hybrid embryos were rescued onto an artificial medium. Plants were raised from these embryos and F1 seeds were obtained by selfing. The fatty acid composition of the F1 seeds showed a shift towards the canola parent. To stabilize the fatty acid composition and improve the agronomic characteristics of B. juncea, a breeding strategy needs to be developed. Interspecific crosses and embryo rescue are a viable method to alter the fatty acid composition of B. juncea towards canola quality for human consumption.