Kenaf (Hibiscus cannabinus) is an annual herbaceous plant of the family Malvaceae that has been planted in Africa for more than 4000 years and used as source of fiber, energy and feed stock. Also, kenaf seeds are good source for edible oil used for first class cooking oil and margarine production. The seeds can be used for lubrication, soap, paint and varnishes. This study was carried out to evaluate fatty acids variation among sixteen kenaf germplasm and gamma-ray induced mutants derived from Jinju and Auxu. Linoleic, oleic, and palmitic acid were the predominant fatty acids in all kenaf seed oils. The sixteen accessions showed a wide range of fatty acid compositions, spanning from 28.94 to 43.36% saturated, 56.64 to 71.05% total unsaturated, 15.52 to 46.85% monounsaturated, and 13.56 to 48.97% polyunsaturated fatty acids. The mutant lines derived from Jinju, significantly surpassed parental mean for all the palmitic and oleic acid. Also, the mutant lines derived from Auxu showed broad ranges of variation in oleic and linoleic acid and narrow ranges of variation in stearic and palmitic acid. The relative amount of monounsaturated fatty acids (MUFA) were increased at all the gamma-ray induced mutants. These results will provide a valuable information to assist parental selection of kenaf breeding.

Mutation breeding is characterized by its merit, creation of new mutant characters and addition of very few traits without disturbing other characters of variety. Gamma ray is generally used to induce mutation in various crops. Heading dat is one of the key factors in the regional and seasonal adaptation of rice verity. This study was carried out to evaluate agronomic characteristics, genetic variation and grain quality of early heading rice (Oryza sativa L. cv. Dongjin 1) lines derived from gamma-ray (Co60, 300 Gy) irradiation. The average heading date of the early heading lines in M7 and M8 generation was faster than that of mother verity as 11 (line γ-2), 10 Aug (line γ-5), 6 Aug (γ-1 line), 5 Aug (γ-3 and X-1), 4 (line γ-4) days, respectively. The selected lines showed shorter culm length and ear length compared with the control. Total spikelets per panicle, percent ripened grain and thousand grain weight of the lines were also mostly shorter or lower than those of the control except total spikelets per panicle of γ-4 and γ-5 lines. When genetic variations of rps16-trnK region were evaluated by nucleotide analysis, nucleotide length of the rps16-trnK region was 664 bp in all the early-heading lines and control. Out of 5 sites of nucleotide transposition detected in the region, however, 2 sites were appeared only in the early-heading lines. Amylose content of the early heading lines ranged from 18.3% to 18.4% and the content was included in high eating quality. Protein content of the lines ranged from 6.6% to 7.0%. The content belonged to Top-rice showing under 7% of protein content. Toyo taste value of the lines ranged from 76.3% to 84.8%.