Pakistan Journal of Biological Sciences1028-88801812-5735Asian Network for Scientific Information10.3923/pjbs.2003.1059.10662 and Combinations of NaCl and CaCl2]]>AlamM. Z.StuchburyT. NaylorR.E. L.RashidM. A.122003612Water uptake and pattern of germination of two rice cultivars differing in seed size were
determined in iso-osmotic solutions of NaCl and polyethelene glycol, different
concentrations of CaCl2 and combinations of NaCl and CaCl2. The results demonstrated
that full imbibition of rice seeds occurred at around 30% moisture content (mc) and the
critical mc for germination was around 25-30%. Although rates of water uptake in rice
seeds were reduced with increasing salinity, rice seeds attained full imbibition by 48 h
up to 150 mM salinity and reached at least critical mc by 72 h up to 250 mM salinity.
Water uptakes in NaCl solutions were greater than in iso-osmotic solutions of PEG and
rice seeds did not attain even critical mc in PEG solutions lower than -0.232 MPa even
after 72 h. When Ca was added in combination with NaCl, water uptake in rice seeds
increased. Water uptake in smaller seed was less during the first 12 h of imbibition than
larger seeds. However, equilibrium mc was attained within 48 h in both large and small
seed. The onset of germination declined with increasing concentrations of NaCl and in
iso-osmotic solutions of PEG, particularly below-0.457 MPa osmotic potential. Large
and small grain rice seed differed significantly in their response to salt and osmotic
stress. Supplemental Ca (3 to 9 mM) significantly increased germination percentage
compared to no Ca salt stress. Three mM Ca completely offset the deleterious effects of
150 mM NaCl and 6 mM Ca partially offset the deleterious effects of 225 mM NaCl on
rice seed germination. Nine mM Ca significantly increased germination in large seed
cultivar but not in the small grain cultivar compared to 6 mM Ca.]]>Akhtar, L.H., J. Gorham and M. Nasrullah,1999Gossypium hirsutum L. cv. Acala SJ2.]]>42260272Alam, M.Z.,20012001Azaizeh, H., B. Gunse and E. Steudle,19922 on water transport across root cells of maize (Zea mays L.) seedlings.]]>99886894Bewley, J.D. and M. Black, 19941st Edn.,Bradford, K.J., P. Dahal and B.R. Ni,19921239248Cramer, G.R., A. Lauchli and E. Epstein,19862 on ion activities in complex nutrient solutions and root growth of cotton.]]>81792797De, R. and R.K. Kar,1995Vigna radiata) under water stress induced by PEG-6000.]]>23301308Falleri, E.,1994Pinus pinaster Ait.]]>22591599Gulzar, S. and A. Khan,2001Aeluropus lagopoides.]]>87319324Gurmu, M. and R.E.L. Naylor,1991Sorghum cultivars.]]>19373383Hadas, A.,197627480489Hampson, C.R. and G.M. Simpson,1990Triticum aestivum). II. Early seedling growth.]]>68529532Hegarty, T.W.,19781101119Huang, J. and R.E. Redmann,1995Hordium and Brassica species during germination and early seedling growth.]]>75815819Katembe, W.J., I.A. Ungar and J.P. Mitchell,1998Atriplex species (Chenopodiaceae).]]>82167175Khan, M.S.A., A. Hamid and M.A. Karim,1997Oryza sativa L.).]]>179163169Kurth, E., G.R. Cramer, A. Lauchli and E. Epstein,19862 on cell enlargement and cell production in cotton roots.]]>8211021106Lauchli, A. and E. Epstein,197045639641Mexal, J., J.T. Fisher, J. Osteryoung and C.P.P. Reid,197555914916Nakamura, Y., K. Tanak, E. Ohta and M. Sakata,19902+ on elongation and intracellular concentration of K+ in intact mung bean roots under high NaCl stress.]]>31815821Rogers, M.E., C.L. Noble, G.M. Halloran and M.E. Nicolas,1995Trifolium repens L.) populations selected for high and low salinity tolerance.]]>23277287Roundy, B.A., J.A. Young and R.A. Evans,198577129135Werner, J.E. and R.R. Finkelstein,1995Arabidopsis mutants with reduced response to NaCl and osmotic stress.]]>93659666Zidan, I., H. Azaizeh and P.M. Neumann,199093711Naylor, R.E.L.,19911991pp: 197-204pp: 197-204Bliss, R.D., K.A. Platt-Aloia and W.W. Thomson,19869721725