Effect of the halophytic grass Sporobolus robustus Kunth as a potential nurse plant on the germination and establishment of Vachellia seyal and Prosopis juliflora under saline conditions

Abstract

Here, we tested the hypothesis that the halophytic grass Sporobolus robustus acts as a nurse plant by enhancing the germination, growth, survival, mycorhization and soil mycorrhizal potential of Vachellia seyal and Prosopis juliflora, and reducing soil salinity. Seeds of each legume were sown 3 cm from a 5-month-old tussock of S. robustus (+) or without S. robustus (−) as a control in a saline soil under greenhouse conditions. Seedlings of each legume were also individually planted 3 cm from a tussock of S. robustus (+) or without S. robustus (−). Sporobolus robustus (+) treatment improved the germination rate for P. juliflora (from 37 to 47%) and for V. seyal (from 23 to 43%). Furthemore, the S. robustus (+) treatment significantly increased P. juliflora and V. seyal seedlings survival (82 and 50%, respectively), mycorrhizal colonization (33 and 35-fold, respectively) and soil mycorrhizal potential (11 and 22-fold, respectively) compared to the control, whereas, no significant effect of S. robustus was observed on the growth parameters of either set of seedlings. Moreover, S. robustus (+) significantly reduced only the salinity of the rhizosphere for V. seyal. Sporobolus robustus could act as a nurse plant to facilitate establishment of both legumes in saline environments.