ibclogo XVI International Botanical Congess


Abstract Number: 4132
Poster No. = 2398


THE SOLUTE ACCUMULATION: THE MECHANISM FOR DROUGHT TOLERANCE IN NEW THAI RICE (ORYZA SATIVA L.) CULTIVARS


Monthakan Vajrabhaya, Thavorn Vajrabhaya, Warunya Kumpun, and Supachitra Chadchawan, Dept. of Botany, Faculty of Science, Chulalongkorn University, Bangkok 10330 Thailand


Four new Thai rice cultivars were selected from somaclonal variation in vitro. They had been selected under the drought pressure for 5 generations before the progenies were used for the experiments. After five weeks in the nutrient solution containing 150g/L PEG, the six week-old drought tolerant seedlings performed approximately 4 fold increasing in sugar content, while the original drought sensitive line had only 2.5 fold increasing, when compared to the non-stressed plants. Proline content was also determined in these rice lines. When the seedlings were grown under the drought condition for five weeks, nine to fifteen fold increasing in proline content was detected in the drought tolerant rice lines, while the original line showed about five fold increasing in proline content. These data suggested that the better ability in solute accumulation contributed to the better performance in drought tolerance of these new Thai rice varieties.


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