SummaryThe electro-chemical and chemical kinetics of six California rice soils were significantly influenced by the presence of salts up to an EC of 9 mmhos/cm in saturation extract (ECe). Subsamples of each soil salinity treatment were incubated for periods up to 10 weeks after flooding. Most of the changes in Eh and pH values took place in the first 3-4 weeks after submergence. Salinity decreased pH values, but slightly increased the redox-potential. Both ammonification and nitrate reduction were significantly decreased, by increasing soil salinity. Salinity up to 9 mmhos/cm did not affect levels of Bray and Kurtz extractable P, but increased the water extractable Ca, Mg, K and Mn. In DTPA extract, salinity in incubated soils had no effect on Zn in 4 soils, but it decreased Fe in acid and neutral soils. Possible explanations for the electro-chemical and chemical kinetic changes due to flooding and salinity are discussed.

seasons, selection was performed in M2, M3, M4, M5 and M6 generation. Sixteen homogeneous and stabile lines were grown during 2013 season under different conditions in three locations (Sakha, Gemmiza as normal soil and EL-Sirw as saline soil stations). The experimental design was a split plot design with four replications. The main plots were devoted to irrigation intervals, while, sub plots were devoted to induced mutants under different conditions in three stations. During 2014 and 2015 seasons, all the induced mutants were evaluated in RCB design with four replications under conditions of Sakha Agric. Res. Station. Data were recorded on days to maturity (day), 1000-grain weight, grain yield (t/ha) and yield reduction %. Data were recorded on days to maturity (day), 1000-grain weight, grain yield (t/ha) and yield reduction %. The desirable values of early maturity, grain yield (t/ha) and grain yield reduction were recorded for Giza 178 M8-4, Sakha 104 M8-4,101 M8-4, and Giza 177 M8-4under different irrigation intervals 3, 6 and 9 days in different research stations (Sakha, Gemmiza and El-Sirw) during 2013 season. Also, these mutants of Sixteen Entries were differed in Sakha Research Station during 2014 and 2015 seasons, whereas, Giza 178M8-4, Sakha 104 M8-4, Sakha 101 M8-4 and Giza 177 M8-4 recorded the desirable values for days to maturity and highest values for 1000 grain weight and grain yield, Sakha 101 M8-4, Giza 177 M8-4, Giza 178M8-4 and Sakha 104 M8-4 could be used as new promising lines tolerant to stress conditions better than their parents.