In semi-arid regions of the Loess Plateau,water deficiency restricts plant performance. Panicum virgatum(switchgrass), which is a highly versatile grass,had been introduced to the Plateau as a restoration species.To d...In semi-arid regions of the Loess Plateau,water deficiency restricts plant performance. Panicum virgatum(switchgrass), which is a highly versatile grass,had been introduced to the Plateau as a restoration species.To determine if prechilling stratification(PCS) and sulfuric acid scarification(SAS) can optimize establishment,P. virgatum cvs Pathfinder, Trailblazer and Alamo were tested under different ambient water potentials by measuring germination and root and shoot growth along water potential gradients under laboratory conditions. Both PCS and SAS improved total germination percentage(TGP), with PCS being more beneficial. The effect of PCS and SAS on mean germination time(MGT) weakened gradually with increasing drought stress. Both PCS and SAS showed no obvious effect on promoting root and shoot growth. Both PCS and SAS reduced base water potential requirement for reaching 50% germination of Pathfinder and Trailblazer, with this effect greater for PCS.These results indicate that embryo dormancy may be a major factor limiting germination of P. virgatum under drought conditions. Pathfinder appears to be more suitable for a semi-arid environment, whereas Alamo appears to be unsuitable for drought conditions. Given the large difference between predicted value and measured value,the reliability and applicable scope of linear regression estimated ψ_(50) needs further investigation, specification and optimization.展开更多
基金supported by the National Natural Science Foundation of China (31500320)the National Science and Technology Supporting Programs (2015BAD22B01)
文摘In semi-arid regions of the Loess Plateau,water deficiency restricts plant performance. Panicum virgatum(switchgrass), which is a highly versatile grass,had been introduced to the Plateau as a restoration species.To determine if prechilling stratification(PCS) and sulfuric acid scarification(SAS) can optimize establishment,P. virgatum cvs Pathfinder, Trailblazer and Alamo were tested under different ambient water potentials by measuring germination and root and shoot growth along water potential gradients under laboratory conditions. Both PCS and SAS improved total germination percentage(TGP), with PCS being more beneficial. The effect of PCS and SAS on mean germination time(MGT) weakened gradually with increasing drought stress. Both PCS and SAS showed no obvious effect on promoting root and shoot growth. Both PCS and SAS reduced base water potential requirement for reaching 50% germination of Pathfinder and Trailblazer, with this effect greater for PCS.These results indicate that embryo dormancy may be a major factor limiting germination of P. virgatum under drought conditions. Pathfinder appears to be more suitable for a semi-arid environment, whereas Alamo appears to be unsuitable for drought conditions. Given the large difference between predicted value and measured value,the reliability and applicable scope of linear regression estimated ψ_(50) needs further investigation, specification and optimization.
