THE EFFECT OF WATERLOGGING ON SEEDLINGS OF EUCALYPTUS MARGINATA

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Summary

Three- to four-month-old Eucalyptus marginata Donn ex Sm. (jarrah) were grown in the glasshouse in peat/sand at 20 °C root temperature, and either waterlogged continuously for up to 14 d, or waterlogged for a shorter time and then drained. During waterlogging, the O2 concentration of the soil solution declined to less than 1 mg l−1within 1 d. There was an increase in the resistance to water movement into or through the plant within 4 d of flooding the pots. The number of xylem vessels blocked by tyloses increased with the duration of flooding, and did not increase further when waterlogging ceased. The transpiration rate of plants continuously waterlogged and maintained in a dry atmosphere for 13d was closely correlated (r =− 0.98) with the proportion of occluded vessels in the tap-root. The rate at which wilting developed depended on both the duration of waterlogging and the transpiration rate.

Ancillary

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