In order to study the proline accumulation in sugar beet plant two sensitive and tolerant lines were sown in sand under the growth chamber condtion and watered by a saline solution. By adding NaCl nutrient solution, proline accumulation for eight mM/Cm2 NaCl was higher in the sensitive line, but at 16 mM/Cm2 NaC1, the proline synthesis of tolerant line was higher than the sensitive one. After five hours of stress the synthesis of proline increased at. the beginning of the treatment and later decreased graduatly.The reasults showed that five hours of saline stress is enough to screen the sensitive and tolerant progeny lines in sugar beet. Moreover 28 days old plants are suitable for the study of proline accumulation. This physiological index can be utilized as a very easy and quick method of screening.
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