|GROVER, KULBHUSHAN - New Mexico State University|
|PALLETE, ANDREW - New Mexico State University|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 11/7/2022
Publication Date: N/A
Technical Abstract: Guar is a legume crop that can be grown for forage, green beans, or for seeds to derive gum used in various industrial products. Due to its ability to tolerate various abiotic stresses, guar can be successfully grown in water deficit conditions and/or with degraded waters, which are generally high in salt contents. The objective of this study was to evaluate four diverse guar genotypes for their salt tolerance in a greenhouse lysimeter system. A detailed analysis of these genotypes was conducted to understand morphological responses and ionic relationships during salinity stress in guar and linked those with underlying genetic determinants. Of the four genotypes, Matador and PI268229 were classified as salt-tolerant, while PI 340261 and PI 537281 were classified as salt-sensitive based on their salt tolerance index (STI) for shoot biomass, root biomass, shoot length, and root length. Ion analysis showed that leaf Na concentrations were 4 to 5.5-fold higher, and leaf Cl concentrations were 1.6 to 1.9 higher in salt-sensitive lines than salt-tolerant lines under salinity. The strong association between the leaf K concentrations under salinity compared to the control (K-salinity/K-control) ratio and STI advocates higher importance of K-salinity/K-control than total leaf K concentrations. The expression analyses of genes involved in Na+ and Cl- transport revealed the importance of different component traits of salinity tolerance mechanisms such as the exclusion of Na+/Cl- from the root, sequestration of Cl- in root vacuoles, retrieval of Na+/Cl- from xylem during salinity stress, root to shoot Na+/Cl- translocation, and K+-Na+ homeostasis.