Impact of mutant varieties in Malaysia: challenges and future perspectives for mutation breeding.

Malaysia has made substantial progress in plant mutation breeding with the use of nuclear techniques and related biotechnologies, not only in the development of new mutant varieties but also in the establishment of an excellent nuclear research centre. A total of 53 mutant varieties have been developed, including rice Oryza sativa (19), banana Musa acuminata (one), groundnut Arachis hypogaea (two), orchid Dendrobium 'Sonia' (six), chrysanthemum Chrysanthemum morifolium (seven), hibiscus Hibiscus rosa-sinensis (three), roselles Hibiscus sabdariffa L. (three) and other ornamental and landscaping plants (12). Most of the new ornamental varieties have been developed by both acute and chronic gamma-ray irradiation of seeds, rooted cuttings, bulbs and tissue cultures. Food crops that have an economic impact on sustainable agricultural production are mutant varieties of banana ('Novaria') and rice (MRQ74, MR219-9 and MR219-4). 'Novaria' is a selection made from a mutant, 'GN-60A', of 'Grande Naine' (AAA Musa) identified from gamma-ray treated populations of the Biotechnology Laboratory in Seibersdorf, Austria. 'Novaria' was the first mutant variety, officially released in 1995 by the Malaysian Nuclear Agency as a new variety for its improved characteristics such as early flowering, short stature and high yield. MRQ74 is a type of high-quality fragrant rice with newly induced traits such as resistance to blast, long and slender grain shape, non-sticky and with the elongation properties of cooked rice similar to those of Basmati-type rice. It is an indirect mutant variety released in 2003 and one of its parental lines for cross-breeding was the mutant 'Mahsuri', which was developed through mutation breeding using gamma-rays. In 2014, two new mutant varieties of rice, 'MR219-9' and 'MR219-4', which are drought tolerant, high yielding and resistant to blast, were selected from gamma irradiated material. Despite these achievements, applications of induced mutation have decreased during the past 10 years due to reduced funding. Mutation breeding is still a promising technique for the development of novel varieties which in combination with advanced molecular genetics can bring plant mutation breeding into a new era.