Salinity is a major abiotic stress threatening plant growth and yield. At least 20% of the world’s cultivated land and nearly half of all irrigated lands are salt-affected to some extent. Developing genetically salt-resistant plants is considered a promising approach for alleviating the threats from soil salinity.

Perennial ryegrass (Lolium perenne L.) is a widely used C₃ turf and forage species in Europe and North America. As a native cool-season turfgrass, it is well known for its rapid establishment and good salt tolerance, and many studies have shown high genetic diversity in perennial ryegrass from Europe, but information concerning the relationship between genetic diversity and stress tolerance in ryegrass is scarce.

Dr. HU Tao under the supervision of Professor FU Jinmin from Key Laborato ry of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanic al Garden, obtained seeds of 75 perennial ryegrass (Lolium perenne L.) accessions coming originally from 21 countries on four continents with various growth conditions from the United States Department of Agriculture. Wide variations were found among the accessions for seven functional traits. One regression model (F = 0.49 × F₁ + 0.303 3 F₂ + 0.207 3 F₃) based on principal components analysis (PCA) and factor analysis (FA) was established to ascertain salt tolerance of each accession. The highest variation of the traits and salt tolerance were obtained for accessions from the European group. Wild accessions exhibited more variation in functional traits and salt tolerance than commercial cultivars. Both molecular marker techniques and functional traits were used to conduct phylogenetic analysis, and the majority of accessions from the same or adjacent regions were clustered into the same group or subgroup. The perennial ryegrass accessions with similar salt tolerance had a close phylogenetic background. The patterns in functional trait variations associated with salt tolerance might allow acceleration of the process for improving salt stress resistance in perennial ryegrass.

This research was financially supported by the National Natural Science Foundation of China (Grant: 31071822/C150302), Innovative Program of The Chinese Academy of Sciences (Project: KSCX2-YW-N-068) and the Special Fund for Public Welfare Industrial (Agriculture) Research of China (Grant: 200903001). Relevant results were published in Plant Biology (DOI: 10.1111/plb.12012)entitled “Leaf functional traits variation associated with salt tolerance in perennial ryegrass”.

Article link:
http://onlinelibrary.wiley.com/doi/10.1111/plb.12012/full
 

Relation between salt tolerance and their phylogenetic relationships in perennial ryegrass (Image by Dr. HU)