Effect of low temperature stress on physiological indexes of cold resistance of Stylosanthes guianensis var. intermedia and S. guianensis ‘TPRC2001-1’

To explore cold resistance of Stylosanthes, the vegetative leaves of S. guianensis var. intermedia and S. guianensis ‘TPRC2001-1’ were treated at 4 ℃ for 0 h, 24 h, and 48 h in the present study. Then, the cold resistance-related physiological indexes were measured including relative electrical conductivity, malondialdehyde content, free proline, soluble sugar, and soluble protein. The results showed that S. guianensis var. intermedia had a lower relative electrical conductivity and lower malondialdehyde content, as well as higher free proline, soluble sugar, and soluble protein content than those of TPRC2001-1, which proves that the S. guianensis var. intermedia has stronger cold resistance than that of TPRC2001-1.