ANATOMICAL STUDIES ON RICE (Oryza sativa L.) PLANTS GROWN UNDER DIFFERENT LEVELS OF SALINITY AND TREATED WITH PACLOBUTRAZOL AND GIBBERELLIN | ||
| Journal of Plant Production | ||
| Article 6, Volume 27, Issue 5, May 2002, Pages 2969-2986 PDF (692.48 K) | ||
| Document Type: Original Article | ||
| DOI: 10.21608/jpp.2002.254187 | ||
| Author | ||
| A. M. Sabbour, | ||
| Botany Department, Faculty of Agriculture, Cairo University | ||
| Abstract | ||
| This study was carried out during the two successive summer seasons of 1998 and 1999. The aim was to determine the effect of salinity on anatomical characters of stem and leaf of rice plants and to ascertain to what extent the application of growth substances may compensate the reduction caused by salinity stress. Stem transverse sections illustrate that low salinity concentration of NaCl 68.4 mM reduced main stem diameter on account of the decrease occurred in number and average diameter of parenchymatous layers of the ground tissue. High concentration 205.5 mM NaCl caused a consecutive reduction in the diameter of the main stem. So, in general, salinity treatments cause a reduction in the dimensions of the vascular bundles, thickness of the bundle sheath and phloem tissue as well as the diameter of xylem vessels. Application of paclobutrazol at 250 ppm on plants grown under stress of 68.4 mM NaCl show decrease in stem diameter. This reduction accompanies with decrease in bundle length, bundle width, bundle sheath thickness, air cavities diameter, phloem tissue and xylem vessels diameter. On the other hand, plants stressed by 205.5 mM NaCl and treated with 2000 ppm paclobutrazol show an irrespective increase in bundle length, bundle width, bundle sheath thickness, phloem tissue and diameter xylem vessels. Rice plants grown under stress of 68.4 mM Na Cl and treated with GA3 at 50 ppm show an increase in stem diameter due to the increase occurred in the thickness stem wall. Unless GA3 treatments resulted in a decrease in the thickness of bundle sheath, thickness of phloem tissue and diameters of xylem vessels were increased. Internal structures of leaf as affected by salinity treatment show a reduction in diameter of midvien as well as leaf lamina thickness. This reduction compressed all tissues shared in leaf structure. Application of paclobutrazol at 250 ppm on plants grown under stress of 68.4 mM NaCl induced a decrease in midvein thickness. At the same time, paclobutrazol treated plants show an increase in the leaf lamina thickness. Mesophyll thickness was increased as well as both upper and lower epidermal cells. Plants grown under salinity stress of 68.4 mM Na Cl and treated with GA3 at 50 ppm show a considerable increase in the thickness of leaf lamina as a result to the increase occurred in the thickness of both upper and lower epidermis as well as mesophyll tissue. It could be concluded that using paclobutrzol and GA3 compounds may compensate the depression observed in internal structure of that moderately salinity stressed plants. But it did not compensate the inhibitory effects of the high level of salinity. | ||
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