Salt Tolerance Evaluation of Seven Legume Forages at Seed Germination Stage

In order to provide reference for the selection of saline-alkali tolerant legume forage plants for the ecological restoration of salinized soil, the seeds of Sesbania cannabina, Crotalaria pallida, Minnan forage (India) Vigna unguiculata, Indonesian Vigna rabiata, Senna tora, Acalypha supera, and Chamaecrista mimosoides were taken as the materials, and different concentrations of NaCl solution and Na₂SO₄ solution 0(CK), 50, 100, 150 mmol/L were used for the stress treatment. The daily germination number of each legume forage seed was counted, and the cumulative germination rate, germination rate, relative germination rate and relative salt damage rate were calculated. The results showed that low concentration of salt solution (50 mmol·L^-1) could promote the initial germination time of Sesbania cannabina and Crotalaria pallida seeds, while high concentration of salt solution (150 mmol·L^-1) could delay the initial germination time of Crotalaria pallida, Senna tora, Chamaecrista mimosoides and Acalypha supera, and inhibit the seed germination. According to the membership function formula, under the stress of NaCl, the salt tolerance of seven forage seeds was as follows: Minnan forage (India) Vigna unguiculata>Crotalaria pallida>Indonesian Vigna rabiata>Sesbania cannabina>Senna tora>Chamaecrista mimosoides>Acalypha supera. Under the stress of Na₂SO₄, the salt tolerance of seven forage seeds was as follows: Minnan forage (India) Vigna unguiculata>Sesbania cannabina>Senna tora>Crotalaria pallida>Chamaecrista mimosoides>Indonesian Vigna rabiata>Acalypha supera.