The present study was desi9f\ed 10 compare Ihe eHectiveness of helium-neon
laser rays (0.0. 60, 120 and 180 minutes) and EthylmethansulphOnale (EMS) (0.0, 5. 15
and 25 mM). each alone or in combination, In Improving lhe tolerance to salinity in salt-
sensitive Giza 168 wheal culuvar. The salt-toleran; Sakna 93 cultivar. was used 10 be
compared with the seosltive one under the same s.alinily levels (0.0, 15%, 30% and 11 5%
sea saJled water). For this reason prellmlnary experimenl was conducunq during
1999f2000 season, and the main experiments during 2000/200 t and 200112002
seasons. The results 01 tne main experiments continmed the previous coodiuoos drawn
from the data obtained from the prelimInary one. The most promisin-g Ihree treatments
were, 120 min. Laser rays, 15 mM EMS and 120 min. laser rays .• 1S mM EMS. The
obtained results of the main experiments clearly cooflrrned Ihe eHectiveness of all
selectee treatments with an absolute superlorlty of combined treatment (120 rnln. laser
rays .• 15 mM EMS) which yielded slgnlnc..:3f'lt (and at me mean lime Ihe hlg est)
increases In the caJl1 fr&sh weighl over Ihe untrealed calli eilher which the derived hom
the tolerant and sensitive cuJlivars Meanwhile. the other two treatments. i.e. ,20 min.
laser rays or 15 mM EMS recorded their slgni1icant tncrsrnents over lhe respective
values 01 the sensitive control only (control II). Also, the Cof Ll1e
combined treatment sxhlbited more tolerance 10 salinity and was able to produce the
signifICant Increment over both controls up to 30% sea salted water level, and only up
10 15% sea salted water level for the other treatments. The obtained wheat plantlets
derived (rom calli treated with the combination of laser rays + EMS were tolerance up 10
30% sea sausd water level and were able to continue Iheir growth in sand cullure till
maturity and lJ11 grain production which yielded as grains I plant more than t\ ••• o lolds of
the control 01 the tolerant cintivars S8J<he 93 and more man four folds I.hal of Ihe
sensuive one Giza 168.. The data also revealed lhal tolerance Which was more
pronounced as a re.sult 01 the double treatment exist as well 8S for (he single Ireatmenl
of each and was assoclated with high accumuladon of much mora quantities Inorganic
osmolica, i.e. N, p. K, Mg, Ca and Ihe hlghesl KfNa ratio as well as lowest quanlilies 01
Na and lowest Na I Ca ratio. In addition to considerable accurnulation of organic
protective osmolytes. i.e. sucrose, proline This was accompanied with an accumulation 01 endogenous hormones, i.e. 1M. GAJ
and A8A in the stressed shoo IS . In add,lion 10 tJ'ic lowest invertase acltvlty in !)"Ie
stressed leaves in favol 01 accumulation mote !'>On·reducing sugars. Such accumurano«
increased as llle ~llnily level W orotective and toxic iruerrneoiates of metabolism in favour of more tolerance 10 sauoirv.
Such behaviour seems to induce more ability lor wheal plants 10 continue Ihc'lr Grow1h
lill maturity and orcouction of grains even under 30% sea sailed w;Jler. The. p'oduccd
wheal grains from Ihe differenl lIealrnenis esoeciauy Ihe double ooe wele
cbarsctertzeo wilt·, InCle.3sed accumulation of protein. sugars and mineral nutrienlS by
inCfessing salinity level In the medtum. SOdium levej gradually decreased Iron, Ihe calli and shoot tissues 10 attain minimum value in U1e produced gfClins. The obtained data
suggested the possibility of successful applicglion of the combination of laser rays and
EMS 10 improve salinity tolerance of economic crops such as wheal.