Photoperiod Insensitive Mutant White-seeded Sesame Line

Abstract

Aromatic sesame varietal improvement for photoperiod insensitive was conducted in Ubon Ratchathani Field Crop Research Centre (UBFCRC). Loei seeds (white local variety) were irradiated by Gamma-Ray at 400 Gy in 2000, and 20 M₂-plants were selected. Selection of M₂-plants comparing to Loei was carried out in early and late rainy season of 2001-2002. Fifty percentage of flowering date and harvesting date of mutant lines were 45-47 and 130 days after emergence (DAE) respectively. Where as those of Loei were 70 and 152 DAE respectively. Forty-four M₃-plants were selected in 2001. In 2002, 65 M₄-plants were selected. Their flowering and harvesting dates were 45-55 and 120-124 DAE respectively; on the other hand, Loei did not flowered. Mutant lines yielded 17.2-22.7 g/plant and 1,000 seed weight were 1.89-2.08 g Whereas Loei yielded 10.3 g/plant and 1,000 seed weight 1.75 g twenty mutant lines were selected as they had good taste equivalent to Loei. Yield evaluation of 20 mutant lines comparing to Ubon Ratchathani 2 (recommended variety), was conducted in early and late rainy in 2003-2004. In early rainy season, the results showed that flowering and harvesting date of mutant lines were 54-60 and 120-130 DAE, respectively while Ubon Ratchathani 2 was 35-37 and 89-90 DAE respectively. The mutant lines yielded 54-86 kg/rai and 1.75-2.01 g/1,000 seed weight. Whereas Ubon Ratchthani 2 yielded 90 and 108 kg/rai and 3.34 and 3.30 g/1,000 seed weight. However, in late rainy season, flowering and harvesting dates of mutant lines and check were not significant difference (32-35 and 87-90 DAE respectively). The Mutant lines yielded 36-93 kg/rai and 1.61-2.03 g/1,000 seed weight. Ubon Ratchathani 2 yielded 78 and 118 kg/rai and 3.07 and 3.42 g/1,000 seed weight. Yield and seed size of mutant lines were lower than Ubon Ratchathani 2. Therefore, 3 mutant lines, Lm 3-2-1-1 Lm 14-1-1-3 and Lm 14-1-1-1, photoperiod insensitive and has as good taste (aromatic) as Loei were selected for further breeding improvement. The mutant lines had higher oil content (34.6-43.9%) and protein (25.2-25.8%) than Loei (33.4 and 24.6%) and Ubon Ratchathani 2 (37.6 and 25.5%)