In arid and semi arid region with irrigated agriculture conditions .excess sotuble
salts often occurs .Bread wheat is one of the primary crops used for human feeding
.The wheat root response type of salinity tolerant and salinity sensitive cultlvar against
to salinity hazard is unclear. The wor1( aimed to study the effect of soit salinity levels (
0.08 .0.2. 0.4and 0.6 %)were assessed on root growth and root cation exchange
capacity in relation to N.P and K content of two wheat varieties (Sakha 92 • salinity
tolerant and Gernmiza 9 • salinity sensitive) The obtained results can be summarized In the following Raising soil salinity level from control to 0.2 % caused an increase in root dry
weight of both varieties . while soil salinity levels above 0.2 % high significantly
decreased root dry weight. Sakha 92 cv. all over the growth stages ga ••• e the highest values of root dry weight than that of the another one (Gemmiza 9 ) where root weight of Sakha 92 represent 108.8 % of Gemmiza 9 C v, at tillering stage. 104.0 % at flowering and 104.9 %at maturity Root cation exchange capacity values of wheat roots at flowering stage
represented 122.70% and 169.73 % of that at lillering and maturity stage .respectivety .
Soil salinity level of 0.2% led to a rise root cation exchange capacity (a ••• erage
of the two wheat varieties) by 2.58% compared to control at tillering stage, and by
1.93% compared to control at flowering. At maturity, the same treatment of soil
salinity led to decrease root cation exchange capacity by 9.31 % ( from 4.264 meq/100
gm to 3.867 meq/l00 gm ) compared to control. Soil salinity le ••• el abo ••• e 0.2 % decreased root cation exchange capacity of wheat roots 10 a large extent at flowering stage. Root cation excl1ange capacity values of Sakha 92 cv. were found to be higher
at any growth stage, than that of Gemmiza 9 c«. Root cation exchange capacity positi ••• ely correlated with root weight in each
physiological growth stage. Soil salinity to a large extent controls nitrogen concentration of wheat roots , which positively correlated with root calion exchange capacity at any physiological s:age.
The reduction in nitrogen percent due to salinitv ~,alard was higher in Gernmiza 9 cultivar ( salinity sensitive) than that of Sakha 82 culti ••• ar ( salinity tolerant) at any growth stage. Positive correlation between wheat roots calion exchange capacity and phosphorus percent of wheat roots was found. Potassium concentration of roots significantly correlated with root cation exchanqe capacity and the correlaticn coefficient value cifferd [rom physiological stage to another, where it was 0.4642 (or tillering • 0.7478 for flowering and 0.6095 for maturity stages.