Oilseed cultivars developed from induced mutations and mutations affecting fatty acid composition

Abstract

One hundred and sixty-three cultivars of annual oilseed crops, developedusing induced mutations, have been officially approved and released forcultivation in 26 countries. The maximum number of cultivars have beenreleased in soybean (58), followed by groundnut (44), sesame (16), linseed(15), rapeseed (14), Indian mustard (8), castorbean (4), white mustard(3) and sunflower (1). The majority (118 of 163) of the cultivars havebeen developed as direct mutants and 45 of 163 by using the inducedmutants in a crossing programme. While in soybean 53 out of 58 cultivarswere selected as direct mutants, in groundnut 22 from 44 were developedafter hybridization. Eighty-three cultivars were developed directly byexposing seeds to gamma or X-rays. Attempts have been made to inferthe successful dose range, defined as the range which led to thedevelopment, registration and release of the maximum number of mutantcultivars for gamma and X-rays. The successful dose ranges in Gy forthe main oilseed crops are: soybean 100-200, groundnut 150-250, rapeseed600-800, Indian mustard 700 and sesame 100-200. The maincharacteristics of the new cultivars, besides higher yield, are altered planttype, early flowering and maturity and oil content. Mutants altering fattyacid composition have been isolated in soybean, rapeseed, sunflower,linseed and minor oil crops. New cultivars having altered fatty acidcomposition have been released in rapeseed, sunflower and linseed. Thelatter, previously grown for non-edible oil, has been converted to a newedible oil crop.