Screening of Tomato Inbred-Lines for Drought Tolerance at Germination and Seedling Stage

This investigation was carried out to screen 45 tomatoes inbred-lines’ response to drought at germination and seedling stage. These inbred-lines which were collected from different countries were screened with osmotic concentration of 12.5% polyethylene glycol 6000 while their respective control treatments were treated using distilled water for twelve days at germination stage. Relative germination energy, relative germination rate, relative germination index, relative vitality index and the relative PEG injury rate were computed to identify the most tolerant inbred-lines on germination stage. Inbred-lines TTI1103B-2, A0911, Roma, L12, and TTD210B were found to be the most tolerant. While inbred-lines L9, TTI1109B-1-2-1, A4, B6 and A7 were the most sensitive to drought. Moreover, analysis of variance revealed significant differences among the inbred-lines studied. The experiment was repeated for confirmation and the result was similar. An additional study was conducted on 30 days old seedlings to observe their water stress response at their seedling stage. A total of 30 inbred-lines, 10 inbred-lines each from tolerant, moderate and sensitive; were selected based on the results found at germination stage. After proper watering for 30 days, watering was stopped for the following 10 days. After that, the dead and alive was counted. The seedlings were then re-watered for the following one week and those recovered from dead were counted again. Finally, the dead percentage and recovery percentage was computed as an indicator of water stress tolerance. And the result was very similar to the experiment done on germination stage.