Pak. J. Bot., 39(1): 135-140, 2007. | Back to Contents | ||||
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Updated: 09-07-09 | ||||
ROLE OF MERCURY AND EXOGENOUS IAA ON XYLEM VESSELS AND SIEVE ELEMENTS IN CUCUMIS SATIVUS L. NAJMA YAQUB CHAUDHRY1* AND AISHA SALEEM KHAN Abstract: High concentration of Hg i.e., 50 ppm and 100 ppm HgCl2 was
used to find the deleterious effects in internode of Cucumis sativus
L. Xylem vessels and sieve tube members showed inhibition with mercury
in both transverse and longitudinal planes. All data was compared with
control plants grown under same conditions. When Hg was applied with
IAA, there was less inhibition in growth as compared to plants treated
with Hg alone, revealing the dominant role of IAA. Therefore, IAA can
be beneficial in reducing the inhibition caused by mercury stress. The
arrangement of vascular tissues within the bundle is bicollateral and
hence the development of phloem region on both sides was studied. Xylem
vessels and phloem cells showed more inhibition with Hg in large inner
vascular cylinder (IVC) as compared with cells in smaller outer vascular
cylinder (OVC).
Punjab University, Botany Department, Lahore, Pakistan.
1 Tel: 042-5889564, 2Tel: 042-7514264 |
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