An Integrated Method for Evaluation of Salt Tolerance in a Tall Wheatgrass Breeding Program

Area of Science:

• Plant Science
• Agronomy
• Genetics

Background:

• Tall wheatgrass is a key forage species for coastal saline-alkaline lands, crucial for establishing a
• Salt-tolerant and high-yielding varieties are essential for successful implementation of coastal planting initiatives.

Purpose of the Study:

• To develop and validate an integrated method for evaluating salt tolerance in tall wheatgrass.
• To identify salt-tolerant tall wheatgrass lines and related Tritipyrum lines for breeding programs.

Main Methods:

• Integrated evaluation of seed germination, seedling emergence, and seedling growth under various salt stress conditions (NaCl, Na2SO4, NaHCO3, Na2CO3).
• Hydroponic culture to assess seedling growth parameters under salt stress.
• Gene expression analysis of salt-response genes (NHX7.1, NCL1) in different tolerance lines.

Main Results:

• Specific salt concentrations (250 mM NaCl, 100 mM Na2CO3) were identified as effective for assessing neutral and sodic salt tolerance via germination tests.
• Relative seedling emergence rates were 52% (250 mM NaCl) and 59.8% (ECw = 6.6 dS m-1).
• Five tall wheatgrass lines and two Tritipyrum lines exhibited significant salt tolerance, with differential gene expression observed in salt-response genes.

Conclusions:

• The integrated evaluation method effectively identifies salt-tolerant tall wheatgrass.
• The identified salt-tolerant lines and Tritipyrum hybrids are valuable resources for breeding programs aimed at coastal land reclamation.
• This research contributes to the development of a 'Coastal Grass Belt' for improved land use in saline-alkaline environments.