Principal component analysis approach for comprehensive screening of salt stress-tolerant tomato germplasm at the seedling stage

Abstract

Salt stress is a major abiotic factor that affects the growth and yield of crops. The present study was carried out to assess the salt tolerance among the Arka Samrat, Arka Rakshak, YVU-1, S-22, YVU-2, and PKM-OP tomato germplasms using principal component analysis (PCA). Different salt (NaCl) concentrations like control, 0.04 M, 0.12 M, and 0.20 M were selected in order to classify them into sensitive and tolerant tomato germplasms based on 13 parameters. A significant variation was observed among the selected tomato germplasms towards salinity tolerance at the seedling stage. Shoot length, root length, fresh weight, and dry weight parameters of the seedlings were decreased linearly with an increase in the external NaCl concentration. Salinization of plants has shown to reduce K ? content and increase in the Na ? accumulation, Ca 2? , and Catalase activity. Salt stress also increased electrolyte leakage and reduced relative water content of all germplasms. The maximum parameters were less affected in Arka Rakshak and Arka Samrat compared to the remaining germplasms at higher salt stress. The PCA analysis of 13 morphological and physiological variables indicated that Arka Rakshak and Arka Samrat germplasms were salt-tolerant and PKM-OP was susceptible. Thus PCA analysis results are useful for the identification of resistance and sensitive germplasms at the seedling stage.

Comprehensive Evaluation of Salt Tolerance in Asparagus Germplasm Accessions (Asparagus officinalis L.) at Different Growth Stages

“…It is well known that salt stress severely impacts crop production worldwide by reducing growth and yield [14,15]. Specifically, the growth parameters of different germplasms show significantly different responses to salt stress, such as the germplasms of cucumber, tomato, and chilli [6][7][8]. In asparagus, we also found that 95 germplasm accessions exhibited different salt tolerance with a large variation.…”

“…In recent years, considerable research on the identification of salt-tolerant germplasm has been carried out in multiple vegetables around the world, such as cucumber, tomato, and chilli [6][7][8], from which some success and experience have been achieved. However, in asparagus, the research is still in the initial stage and lacks depth and breadth.…”

“…However, in asparagus, the research is still in the initial stage and lacks depth and breadth. From many previous studies, we know that plant salt tolerance was evaluated at the germination stage and seedling stage due to their prerequisite roles in determining yield [6][7][8] while the results were usually different in the entire growth period, including the adult stage, another critical stage closer to actual production. us, salt-tolerant identification at the adult stage must be conducted before plants are applied in actual production in saline-alkali soil, which will be more reliable combined with identification at the germination stage and seedling stage.…”

Early Growth Stage Characterization and the Biochemical Responses for Salinity Stress in Tomato

“…In a range of crops, salinity tolerance at early growth stages often reflects greater tolerance than at later growth stages. For different crops, including tomatoes [ 28 , 29 , 38 ], barley [ 39 ], wheat [ 40 ], maize [ 41 ], cotton [ 42 ], and rice [ 43 ], research has shown that genotypes with enhanced tolerance mechanisms have been selected for their resilience to saline environments at the seedling stage. The aim of our present study was to identify salinity tolerance by phenotyping tomato seedlings using quantitative traits such as reduction in mass of roots and shoots, leaf injury due to salt stress, and tolerance indices derived from dry weights and leaf inorganic ions (K + , Na + , and Ca 2+ ) in order to systematically screen salt-tolerant varieties as well as to understand the biochemical mechanisms of salinity stress tolerance in tomatoes.…”

“…Simple correlation analysis is preferred, with pairwise regression of attributes, but it may not give expected results with complex salinity traits. Hence, the use of principal component analysis (PCA) can illustrate the most significant plant attributes governing salt tolerance [ 28 ]. In PCA, a three-way interaction plot aided with clustering can provide efficient prediction of the responses of salinity stress tolerance of the cultivars relying on trait associations existing between morpho-physiological traits and Na + stress [ 29 , 30 ].…”