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Description:
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Atriplex halimus L . plants were grown in nutrient culture solutions of full -strength Hoagland's , and fullstrength Hoagland's supplemented with either 0 .174 M NaCl or 0 .345 M NaCl . Observations were made on growth habit , net growth , and leaf cell ultrastructure of plants from the various treatments . Plants grown under control conditions (full -strength Hoagland's with no supplemental salt ) had an erect habit with no lateral branching , but had a reduced net growth in comparison to plants in either of the salt treatments . Plants in the 0 .174 M NaCl treatment were relatively erect (some recumbency was noted ) and exhibited much better growth than either the control treatment or the high -salt (0 .345 M NaCl ) treatment . This is an indication of the plant's need for sodium chloride in the medium as either a nutrient or an osmoticum , and leads to the classification of A . halimus as a halophyte . Plants grown in the high -salt treatment showed a marked recumbency and a reduction in growth , but nevertheless showed a better net growth than plants in the control treatment .
The fine structure of the leaf cells is correlated to salinity treatments . Plants grown in high -salt treatments showed swelling of organelles (chloroplasts and mitochondria ) and other structural differences . The hair cells , which showed little ultrastructural response to high -salinity treatments , were characterized by unique ultrastructural features directly related to salinity tolerance . |