ENVIRONMENTAL AND INDUCED MUTATIONS INFLUENCES ON OIL CONTENT, OLEIC ACID AND ERUCIC ACID IN RAPESEED

A comparative study was conducted to see the mutational analysis for monounsaturated fatty acids in rapeseed (Brassica napus L.) mutant populations. By using gamma irradiation, a range of variability generated for oil content and fatty acid composition in rapeseed seeds. The induced genetic variability was analyzed for two consecutive years in two contrasting environments at elevations of 510 and 2039 meters. In both cases induced variability differences were estimated for oil content as well as oleic Acid (C18:1) and erucic Acid (C22:1). Across radiation treatments, the direction and magnitude of induced variability were related to environmental influence. The gamma irradiation enhanced synthesis of oleic acid but induced different spectrum of variability for this desirable monounsaturated fatty acid at two locations. Desirable canaola quality modification i.e. low erucic and high oleic acid in rapeseed oil have been observed but with diverge pattern in same gamma dose mutant populations at two locations. The gamma dose 1200 Gys reduced oleic acid at Peshawar but same dose increased oleic acid at Kaghan. Gamma irradiation also affected in different way for erucic acid trait at two locations. These results demonstrated that variation in growth environments can cause differences in genetic variability for monounsaturated fatty acids in rapeseed through induced mutations. Furthermore, environment influence can significantly affect the selection index for oil yield and oil quality traits in rapeseed.