Evaluation of Salt Tolerance in Italian Ryegrass at Different Developmental Stages

Abstract

Soil salinity is one of the major abiotic stresses that continues to threaten plant growth and agricultural productivity. Screening germplasm with salinity tolerance is therefore necessary. This study was designed to evaluate salt tolerance based on the integrated tolerance index. Fifteen Italian ryegrass cultivars were used to evaluate the degree of genotypic variation in salt tolerance at the germination and vegetative growth stages of plant development. Evident variations in salt tolerance were observed at the germination stage under 255 mM NaCl treatment. Root growth rate, chlorophyll content, and germination rates played a vital role in determining salt tolerance. Based on combined attributes at the germination and vegetative growth stages, Gongniu, Chuangnong, Splendor, and Abundant were identified as the most tolerant cultivars. Furthermore, the constant crude protein, lower neutral detergent fiber, and acid detergent fiber contents were measured under salinity. Compared to the control, the cultivars Tetragold, Abundant, Splendor, Muyao, Harukaze, Tegao, Dongmu 70, and Doraian were identified to have high forage quality under salt stress. Finally, we selected Splendor and Abundant as the cultivars that expressed the highest degree of salt tolerance based on combined attributes related to germination, salt tolerance, and overall forage quality. In addition, gene expression analysis between salinity tolerant and sensitive cultivars revealed that the gene response to photosystem and carbohydrate synthesis may have played a mediating role in providing tolerance to salt stress.

Enhancing Agrobiodiversity: Designing an In Vitro Screening Protocol for Solanum lycopersicum L. and Solanum pimpinellifolium L. to Explore Responses to Salinity Stress

“…The use of a sucrose-free culture medium did not impede seedling development and facilitated autotrophic growth [25] of the studied Solanum spp., resulting in a response closely resembling that observed in vivo. Additionally, the use of sea salt, rather than simple sodium chloride, enabled the recreation of seawater conditions [26].…”