供磷水平对柳枝稷光合特性与抗逆生理的影响

Effects of phosphorus supply level on photosyntheticcharacteristics and stress resistance physiologyof switchgrass

摘要:

【目的】 探究盐碱条件下供磷水平对不同品种柳枝稷光合特性与抗逆生理的影响。【方法】 采用双因素随机区组试验设计进行盆栽试验，设置3 个柳枝稷品种（Alamo 加倍体、Alamo 和Path-finder）和3个供磷水平[不施磷（ P0）、低磷10 mg/kg（ P10）、高磷100 mg/kg（ P100）]，比较不同供磷水平下各品种柳枝稷光合特性、抗氧化酶活性、渗透调节物质含量的变化规律，综合评价不同柳枝稷品种抗逆性。【结果】 柳枝稷叶片叶绿素a、b 含量、净光合速率、气孔导度、蒸腾速率、脯氨酸含量随供磷水平的增加而增加，其中Alamo 加倍体品种P100 处理较P0 处理分别增加了57. 3%、62. 9%、41. 4%、29. 7%、55. 2%、128%；胞间CO2浓度、过氧化氢酶活性（CAT）、可溶性糖含量（SS）随供磷水平的增加而降低，其中Alamo 加倍体品种P100 处理较P0 处理分别降低了51. 7%、84. 4%、20. 9%。高磷处理下Alamo 加倍体的净光合速率、超氧化物歧化酶活性（SOD）和脯氨酸含量均最大，表现出较强的生理活性。【结论】 盐碱条件下施磷提高了柳枝稷的光合能力和抗逆性，以高磷处理下Alamo 加倍体的抗逆性最强。

Abstract:

【Objective】 The aim of the study is to explore the effect of phosphorus supply level on photosyntheticcharacteristics and stress-resistant physiology of different varieties of switchgrass under saline-alkali conditions.【Method】 A pot experiment was conducted using a two-factor randomized block design. Three switchgrass varieties（Alamo syndiploid，Alamo and Pathfinder） and three phosphorus supply levels （no phosphorus 0 mg/kg （P0），lowphosphorus 10 mg/kg （P10），high phosphorus 100 mg/kg （P100）） were set. The changes of photosynthetic charac-teristics，antioxidant enzyme activity and osmoregulatory substance content of switchgrass varieties under differentphosphorus supply levels were analyzed and compared， and their stress resistance was comprehensively evaluated.【Result】 The results showed that leaf chlorophyll a and b contents，net photosynthetic rate， stomatal conductance，transpiration rate and proline content of switchgrass increased with the increase of phosphorus supply level. And thevalues for Alamo syndiploid P100 treatment increased by 57. 3 %，62. 9 %，41. 4 %，29. 7 %，55. 2 % and 128 % re-spectively compared with P0 treatment. Intercellular carbon dioxide content（Ci）， catalase activity （CAT） and soluble sugar content（ SS） decreased with the increase of phosphorus supply level， compared with P0 treatment， thetreatment of P100 of Alamo syndiploid variety decreased by 51. 7%，84. 4% and 20. 9%. The net photosyntheticrate，SOD activity and proline content of Alamo syndiploid were the highest under high phosphorus treatment.【Con-clusion】 Comprehensive analysis showed that phosphorus application under saline-alkali condition improved photo-synthetic capacity and stress resistance of switchgrass，and Alamo syndiploid body under high phosphorus treatmenthad the strongest stress resistance.