ESTIMATION OF SALT TOLERANCE POTENTIAL OF SYNTHETIC HEXAPLOID WHEAT BASED ON ION DISCRIMINATION

Soil salinity has become a significant problem in agricultural lands making a huge area unavailable for production. Salt affected lands can be exploited effectively by utilization of salt tolerant germplasm for various crops through identification and development of tolerant genotypes. Wheat being a major food crop in many countries come to priority in this regard, and has been subjected to extensive breeding to develop tolerant germplasm. In the quest for novel sources of genes to improve the existing germplasm, several synthetic hexaploids have been developed by exploiting a diploid wheat progenitor, Aegilops tauschii. Some of these synthetic hexaploids were evaluated for their salt tolerance potential using an in vitro test called K+:Na+ discrimination. A total of thirteen genotypes were grown in hydroponics at a salinity level of 75mM NaCl. Eight genotypes showed tolerance by discriminating between Na+ and K+ ions under saline conditions. SH-13 and SH-11 were the most tolerant genotypes with good agronomic characters under salt stress, while SH-3, SH-5, SH-7, SH-8, and SH-12 showed the highest 1000 grain weight and more grains per spike in the field. A positive correlation was found between root and shoot length and K+/Na+ value of the tolerant genotypes. The results suggested that the genes for salt tolerance have been transferred in the synthetics from wild species which can be exploited through their utilization in wheat breeding programs.