Effects of phosphorus supply level on photosynthetic characteristics and stress resistance physiology of switchgrass
[Objective]The aim of the study is to explore the effect of phosphorus supply level on photosynthetic characteristics 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),low phosphorus 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 different phosphorus 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 the values 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,the treatment of P100 of Alamo syndiploid variety decreased by 51.7%,84.4%and 20.9%.The net photosynthetic rate,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 treatment had the strongest stress resistance.
phosphorus supply levelswitchgrass(Panicum virgatum L)photosynthesisstress resistancemMembership function
万方数据
维普
