The arbuscular mycorrhizal fungus Diversispora spurca ameliorates effects of waterlogging on growth, root system architecture and antioxidant enzyme activities of citrus seedlings

Citrus plants are often exposed to heavy rain and subsequent periods of soil waterlogging which severely restrict tree growth. We assessed the effect of one arbuscular mycorrhizal fungus species (Diversispora spurca) on growth, root system architecture (RSA), and antioxidant enzyme activities of young citrus (Citrus junos) seedlings. Waterlogging for 37 d significantly restricted mycorrhizal colonization but increased the number of entry points and vesicles. Compared with non-mycorrhizal controls, mycorrhizal seedlings had significantly greater plant height, fresh mass, total root and taproot lengths, projected and surface root areas, root volume, and numbers of lst, 2nd and 3rd order lateral roots regardless of waterlogging treatment. D. spurca significantly increased root catalase (CAT) activity in non-stressed seedlings and increased root soluble protein concentration and leaf CAT activity in waterlogged seedlings, thereby inducing lower oxidative damage. These results suggest that D. spurca ameliorates effects of waterlogging on growth, RSA and antioxidant enzyme activities.

► 37-d waterlogging reduced D. spurca colonization but increased entry points and vesicles.
► D. spurca increased growth, root traits, and number of lateral roots under waterlogging.
► Higher CAT activity and soluble protein concentration were in waterlogged plants colonized by D. spurca.
► D. spurca confers a higher tolerance to waterlogging stress in citrus plants.