The improvement of wetland rice varieties to earliness short stature and the other important characteristics through induced mutation

Five wetland rice varieties or promising line such as Semeru, Cimandiri, Krueng Aceh, Batang Agam, and IR4432-28-5 were irradiated with gamma ray 60-C at doses 0, 0.3, and 0.4 kGy. Ml seeds generetion were planted at Muara, the experimental station in the rainy season 1982/1983. After selecting step, one mutant from rach varieties were selected in the drying season 1986. All mutant have a good performance in the field. Mutant Semeru is sorter about ten cm, ealier about seven days than parent and reacted moderately to brown planthopper (Nilaparvata lugens) biotype 3. Likewise mutant Cimandiri, which is shorter earlier than parent and 1000 grain weight about 27 g. Mutant Kruen Aceh have 1000 grain weight is higher than parent besides the stem colour change become violet and this plan reacted moderately to BPH 3. Mutant from Batan Agam reacted resistantly to bacterial leaf blight (Xanthomonas oryzae). IR4432-28-5 mutant was got which reacted moderately and resistently to BPH 2 and Sumatera Utara biotype. All mutant reacted resistantly to tungro virus and amylose content are lower than those of the parents. (author). 5 refs, 2 tabs