Genetic evaluation and characterization using cluster heat map to assess NaCl tolerance in tomato germplasm at the seedling stage
Author
Rehman,Fazal
Saeed,Asif
Yaseen,Muhammad
Shakeel,Amir
Ziaf,Khurram
Munir,Hassan
Tariq,Sultan Ali
Raza,Muhammad Ahsan
Riaz,Awais
Abstract
ABSTRACT Salinity is a serious problem that limits crop growth and yield. The present study used plotting to evaluate 25 tomato (Solanum lycopersicum L.) accessions for various morpho-physiological parameters at the seedling stage and identify significantly salt-tolerant tomato lines at three different salinity levels. The pot experiment had a completely randomized design with three replicates in a factorial arrangement under greenhouse conditions. Tomato plants were exposed to 0 (control), 8, and 12 dS m-1 as NaCl stress at the seedling stage. The morpho-physiological traits, such as root and shoot length, root/shoot ratio, number of leaves, fresh and dry shoot weight, fresh and dry root weight, leaf area, Na+ and K+ concentrations, K+/Na+ ratio, and tolerance index, were recorded to examine salt tolerance. According to principal component analysis (PCA), there were six principal components (PCs) with Eigen values > 1 and 77.2% of total cumulative variability. The PC1 (24.3%) revealed the highest variability followed by PC2 (16.2%). Meanwhile, the PCA biplot and cluster heat map analyses indicated that Subarctic, Raad-Red, Naqeeb, Pakit, Tommy-Toe, and BL-1076 were salt-tolerant, whereas PBLA-1401, PB-017902, CLN-2413, BL-1078, BL-1174, and BL-1079 were the most susceptible accessions based on their performance under stress.