Vol.:(0123456789) 1 3 Journal of Crop Science and Biotechnology https://doi.org/10.1007/s12892-021-00115-3 ORIGINAL RESEARCH Physiological and molecular evaluation of ten Egyptian barley cultivars under salt stress conditions Shaimaa R. M. Khalil 1  · Ahmed Ashoub 2,3  · Basita A. Hussein 4  · Wolfgang Brüggemann 3  · Ebtissam H. A. Hussein 4  · Mohamed S. Tawfik 1 Accepted: 9 September 2021 © Korean Society of Crop Science (KSCS) 2021 Abstract Ten Egyptian barley cultivars (Giza 129, 132, 123, 127, 2000, 130, 126, 135, 128 and 133) were assessed under 0, 100 and 200 mM NaCl. The cultivars performance under salinity was measured in open field conditions using the Fv/Fm and Per- formance Index. Measurements of growth parameters as well as other chlorophyll fluorescence parameters (RC/CS, TFm, RC/ABS and ABS/RC) were also included. Giza 129 is considered salt-tolerant, and Giza 123 is salt sensitive cultivar. Both cultivars, along with Giza 132 (moderately salt tolerant), were used to evaluate the relative expression of the B2 and shmt genes at 0,100 and 200 mM NaCl. The expression of both genes increased in the tested cultivars upon salinity treatment. At 200 mM NaCl, B2 and shmt genes relative expression reached 1.9- and 1.5-folds in the salt-tolerant cultivar (Giza 129); while getting 1.6 and 1.2 folds in the sensitive cultivar (Giza 123). Repeating the same experiment for Giza 129, 132, and 123 under the growth chamber conditions revealed that the effect of salinity was more vigorous at the physiological and morphological levels. In addition, the gene expression was generally higher than that of the open field conditions, although exhibiting a similar trend of results. Our results under the present study indicate that Giza 129 is a candidate for further salinity-breeding studies. Furthermore, a comparison between growth chamber and open field conditions revealed a kind of adaptation of barley PSII to the continuous salt stress in the open field conditions. Keywords Salinity · Chlorophyll fluorescence · Barley · Real-time PCR Introduction Barley (Hordeum vulgare L.) is a member of the Poaceae family and one of the oldest cultivated grains with a culti- vated area of 51 million hectares in 2019 (FAO 2019). Bar- ley has been used for centuries to feed ruminants, poultry, and humans and beverage production (Newman and New- man 2008; Meints and Hayes 2019). Over the past two dec- ades, the demand to incorporate barley in food increased due to its health-beneficial value (Izydorczyk and Edney 2017). Salinity is a limiting factor affecting plant survival and reduces plants-yield via imposing osmotic and ionic stresses. The hyperosmotic effect happens when the osmotic pressure of solutes in the soil elevates to levels exceeding plant cells' ability to absorb their water needs, leading to water migra- tion outside cells and turgor loss (osmotic phase). While hyperionic effects are caused by the excess of sodium ions, resulting in competition and replacement of K + by Na + in catalytic-binding sites of enzymes involved in different metabolic pathways (Chinnusamy et al. 2005; Hyskova and Shaimaa R. M. Khalil and Ahmed Ashoub contributed equally to this manuscript. * Shaimaa R. M. Khalil shaimaa.rm@gmail.com * Mohamed S. Tawfik moh4mon@gmail.com Ahmed Ashoub ashoub@em.uni-frankfurt.de 1 Oil Crops Biotechnology Lab, Agricultural Genetic Engineering Research Institute (AGERI), Agricultural Research Center (ARC), 9 Gamaa Street, Giza 12619, Egypt 2 Agricultural Genetic Engineering Research Institute (AGERI), Agricultural Research Center (ARC), 9 Gamaa Street, Giza 12619, Egypt 3 Institute of Ecology, Evolution, and Diversity, Goethe University Frankfurt am Main, 13 Max-von-Laue-Straße, 60438 Frankfurt am Main, Germany 4 Department of Genetics, Faculty of Agriculture, Cairo University, Giza, Egypt