Assessment of variation among cultivated wheat species for plant nutrient strata under salinity conditions

Abstract

Six wheat genotypes, two each of bread wheat (UAS BW-13897 and LBPY 2014-5), Triticum durum (GW 2010-679 and UAS DW-31403) andT. dicoccum (DIC 99 and DIC 26) were grown under natural saline and control conditions to observe the existence of ion discrimination,ion selectivity amenable to ion regulation and ion interactions among them. Bread wheat genotype, UAS BW-13897 showed a highK+ and K+/Na+ ratio at the harvesting stage under saline condition indicating its high salt tolerance. Contrary to it, T. durum genotype,UAS DW-31403 was found to be highly salt-sensitive due to its low K+/Na+ ratio and high Na+ absorption. Bread wheat genotypes werefound most salt-tolerant due to better exclusion of Na+ salt, with negligible reduction in grain yield, spike length, SPAD and numberof grains per spike. The salt exclusion was found less apparent in T. durum and T. dicoccum wheat likely due to the absence of the Dgenome and Kna1 gene, which is present in bread wheat and not in the two tetraploid species. Durum wheat was observed to be mostsensitive with low salt exclusion capacity, whereas T. dicoccum wheat was found intermediate between bread and durum wheat withmedium salt exclusion capacity. The study revealed a difference in type and level of salt tolerance in different species and genotypesthat established high Na+ salt exclusion capacity as one of the important selection criteria for salt tolerance.