Sesame improvement through mutation induction for reduction of seed loss at harvest (semi-shattering capsules)

In 1994, the study of sesame improvement for reduction of seed loss by mutation was conducted at Ubonratchathani Field Crops Research Center (UBFCRC). There were two experiments carried out to improve sesame capsule for non-shattering characteristics using gamma rays and fast neutrons. The first experiment was performed to study the effect of irradiation doses on sesame when applied at doses varying from 200 to 750 Gy. Results of the experiments showed that all sesame lines had LD50 levels between 300-750 Gy when irradiated with gamma rays, and 20-80 Gy with fast neutron. The second experiment was done to investigate the effect of irradiation on shattering types of sesame capsules. Three local varieties, Red Pitsanulok, Black Burirum and white Granuan were irradiated with 500 Gy of gamma rays. In the dry season 1997-98, 24 plants of M7 generation (black- and red- seeded lines) and 8 plants of M5 generation (white-seeded lines) were selected for yield evaluation with three local varieties. The results show 3 shatter resistant lines, PMUB 1, PMUB 19 (both with shatter resistance scale 537) and GMUB 7 (with scale 637) in 1997-98 (772 in 1997) gave 27% higher seed yield than the original variety; 2 black seeded mutant lines BMUB 21 and BMUB 23 of which seed colour slowly fades and 2 mutant lines (GMUB 1, GMUB 3) with a high degree of tolerance to powdery mildew. (author)