Screening of wheat genotypes and TaSTG gene expression under variable salinity levels

Abstract

Iqra Aslam* , Muhammad Kashif , Zaheer Ahmed , Nisar Ahmed

The present study screened one hundred wheat genotypes at the seedling stage under different salinity levels (0, 5, 10, and 15 dS/m NaCl) under laboratory conditions to assess the effects of salinity. The assessment of wheat germplasm for traits such as root length, shoot length, fresh shoot weight, dry shoot weight, fresh root length, and dry root weight revealed substantial variation in salinity tolerance at the seedling stage. The seedling experiment demonstrated that variation in salinity tolerance exists in wheat at the seedling stage and that improvement in salinity tolerance is possible through selection and subsequent hybridization. The experiment was repeated twice under the same laboratory conditions to assess the reproducibility of the results. Principal Component Analysis (PCA) was performed, based on which Durum wheat (TOB-66) and Bread wheat (Blue Silver) were identified as salt-tolerant genotypes because they performed best for most of traits at different salinity levels, whereas STW-118 and Chenab-2000 were identified as salt-susceptible genotypes. Real-time Polymerase Chain Reaction (RT-PCR) was used to detect the expression of the salinity-tolerance gene TaSTG in the selected wheat genotypes. The expression level of TaSTG increased only in salt-tolerant genotypes and not in salt-susceptible genotypes. These findings suggest that TaSTG may be associated with improved salinity tolerance in the selected wheat genotypes and could be useful for further breeding efforts.