 หัวเรื่อง:ผลของรังสีแกมมาร่วมกับการชักนำให้เกิดยอดจำนวนมากต่อการเปลี่ยนแปลงลักษณะทางพืชไร่บางอย่างของข้าวหอม (Oryza sativa L.) พันธุ์ขาวดอกมะลิ 105 ผู้เขียน: ดร.ประภา ศรีพิจิตต์, รองศาสตราจารย์ ,  Pudcharaporn Tangman, นายวิทยา แสงแก้วสุข, ผู้ช่วยศาสตราจารย์ สื่อสิ่งพิมพ์:pdf AbstractMutation induction of aromatic rice (Oryza sativa L.) was conducted after in vitro multiple shoot induction and gamma irradiation. Seeds of aromatic rice variety Khao Dawk Mali 105 (KDML 105) were irradiated by gamma radiation at the doses of 0, 4, 8, 12, 16, 20, 24, 28, 32, 36 and 40 krad. After irradiation, the multiple shoots were induced from the seeds. The shoots were rooted and the plantlets (M subscript 1 R subscript 1) were grown under greenhouse condition until maturity. It was found that at the lower doses the height of M subscript 1 R subscript 1 plants increased and subsequently reduced at the higher doses. The doses from 4 to 20 krad caused a reduction in the number of days to flowering compared with the other doses. Number of tillers and panicles per plant increased as the dose increased. At the doses of 8 and 12 krad the number of fertile panicles per plant increased and gradually decreased at the doses higher than 12 kard. The percentage of seed fertility decreased as the dose increased. The 1,000 grain weight varied depending on the dose. Chlorophyll variation was observed among M subscript 1 R subscript 1 plants derived from the cultures of non-irradiated and irradiated seeds. In M subscript 2 R subscript 2 generation, plant height, number of tillers, panicles and fertile panicles per plant varied depending on the doses (0 to 36 krad) compared to control which grown directly from seeds of KDML 105. However, the percentage of fertile seeds still decreased when the dose increased. Chlorophyll mutation was also found in M subscript 2 R subscript 2 progenies. It is of interest that the M subscript 2 R subscript 2 progenies derived from cultures of non-irradiated and irradiated seeds were photoperiod insensitive. They flowered when they reached the maximum vegetative growth stage without the influence of short daylength. On the contrary the control grown directly from seeds of the photoperiod sensitive KDML 105, flowered after stimulation of short daylength. The inheritance of photoperiod insensitive character in M subscript 3 R subscript 3 generation will be investigated later. If the photoperiod insensitive character expressed in the M subscript 2 R subscript 2 progenies is heritable, it will be useful for selection of pure line KDML 105 for photoperiod insensitivity. |
หัวเรื่อง:ผลของรังสีแกมมาที่มีต่อการสร้างยอดหลายๆ ยอดของเมล็ดข้าวหอม (Oryza sativa L.) ในสภาพปลอดเชื้อ ผู้เขียน:ดร.ประภา ศรีพิจิตต์, รองศาสตราจารย์, Pudcharaporn Tangman, Wittaya Saengkaewsook สื่อสิ่งพิมพ์:pdf AbstractThe effect of exposure dose of gamma radiation on multiple shoot formation of aromatic rice seeds (Oryza sativa L. cv. Khao Dawk Mali 105) was investigated . The seeds were irradiated by gamma radiation with varying exposure doses of 0, 4, 8, 12, 16, 20, 25, 28, 32, 36, 40 and 44 krad. After irradiation, the seeds were surface sterilized and cultured on Murashige and Skoog medium supplemented with benzyladenine 25 mg/l to induce multiple shoot formation. After 5 weeks cultured the number of multiple shoot – forming seeds and the number of shoots per seed were counted. It was found that the number of multiple shoot-forming seeds was increased from 45.9% in the control to 83.3% in seeds irradiated at 24 krad. At the exposure dose of 28 krad the number of multiple shoot –formation seeds was decreased to 80% and was lowest (11.4%) at 40 krad. Multiple shoots formation was completely inhibited at the highest exposure dose of 44 krad. The exposure dose required to reduce the number of multiple shoot – forming seeds by 50 percent (RD50) was 38 krad. Similarly, the number of shoots per multiple shoot-forming seed was increasing as the exposure dose increased from 5.7 shoots in the control to 21.3 shoots in seeds irradiated at 40 krad, The number of shoots per seed was zero at the exposure dose of 44 krad. The multiple shoots regenerated from irradiated seeds were rooted. Then the M1R1 plantlets were transplanted into pots grown under greenhouse conditions. |