PhD defence Xu Liu

Xu Liu (GREEN)

Promotor: Prof. J.T.M. Elzenga; copromotor: Dr K.J. Tiedge

Key ecophysiological adaptations of alfalfa (Medicago sativa L.) to saline environments

Paving the way for salinity-smart crop development

Soil salinization is spreading all over the world at an alarming rate. There is no continent that is completely free from soil salinization. One of the most promising strategies for this situation is the utilization of stress-resilient plant species, particularly those that are locally adapted, to enhance sustainability in salinized soil. Alfalfa, known as ‘Queen of Forages’, has been widely cultivated in arid and semiarid regions where soil salinization forms a significant threat. It definitely has high nutritional and economic values, as it contains high protein content and an abundance of vitamins. Importantly, modern alfalfa cultivars show greater salt tolerance than many other crop species, such as wheat and rice. Alfalfa does harbor tremendous genetic variation. This diversity offers a rich resource, and has great potential for increasing alfalfa’s, and identifying salinity-tolerance traits in alfalfa might be relevant for other crops’ salinity resilience. To sustain alfalfa production and efficiently select salt-tolerant alfalfa lines with rising salinity levels, it is essential to explore more effective and targeted selecting/breeding strategies. This thesis begins with a review of effects of salinity on plants and their adaptations. It focuses on spatial responses and adaptive strategies in alfalfa with the range of variation to salinity stress. Moreover, promising research lines targeted at developing salt-resistant alfalfa varieties are explored, specifically, plasticity of root system architecture, the fingerprint profiles of specialized metabolites, root K+ homeostasis, and mobilizing beneficial bacteria.

View thesis