Influence Of Organic Silicon On The Salt Tolerance Of Tall Fescue

Increasing soil salinization seriously limited the sustainable and healthy development of turfgrass industries.To decrease the expensive cost of establishment of turfgrass and following management and maintaining the economic and ecological durable developmentcaused by salinization,evaluating,screening of salt-tolerant turf grasses species,development and application of Silicon fertilizers are one of the effective ways to deal with above mentioned problems.In this study,the cold-season turfgrass species,tall fescue?Festuca arundinacea?,which is excellent in stress torlence,was used as a tested material.Following 3 studies were carried out:?1?TP?Top of paper?germination method was used to compare the salt tolerance for five tall fescue strains at the germination stage.Plus distilled water as control,totally 6 NaCl stress content gradient were set to moistening the double layered filter paper.The NaCl content set were50,100,150,200 and 250 mmol·L^-1,respectively.Aimed to screening better strains for salt tolerance;?2?The salt-tolerant variety Tar Heel?was selected as the tested materials from the first experiment.Salt stress was simulated with 150 mmol·L^-11 sodium chloride.Four treatments were totally set,respectively:blank control?distilled water?,A:150 mmol·L^-11 NaCl stress,B:150mmol·L^-11 NaCl stress plus organic silicon spraying on 10^thh day after emergence,C:150 mmol·L^-1NaCl plus 2.5mmol·L^-11 organic silicon mixture regents.To explore the influence of the addition of organic silicon on the germination and early growth of tall fescue;?3?The salt-tolerant variety Tar Heel?was selected as the study object from the first experiment,pot experiment were used,salt stress is simulated with sodium chloride.A total of 3 Na⁺concentration gradients(50,150 and250 mmol·L^-1)were set to to representative lighter,medium and severe salt stress,respectively.Distilled water as the blank control?CK?,and silicon spraying?Si+?and silicon non-spraying?Si-?were respectively set at each salt concentration?including water control?.The spraying concentration of organic silicon was 2.5 mmol·L^-1.The effects of organic silicon spraying on the physiological and biochemical indexes and the quality of turf grass in tall fescue species under different degrees of salt stress were studied.The results were showed as following:1.The germination potential,germination rate,germination index,seed vigor index,shoot and root length as well as salt damage rate had no remarkable difference compared to control?P>0.05?under lower salt concentration(50 mmol·L^-1).Relative germination potential,relative germination rate,relative germination index,seed vigor index,relative shoot and root length decreased with the NaCl concentration increasing,while relative seedling damage rate increased under salt stress,when NaCl concentration ranged from 50 to 250 mmol·L^-1.When NaCl concentration increased to 250 mmol·L^-1,seedings were seriously damaged,at the same time,relative germination potential,relative germination rate,relative germination index,seed vigor index,relative shoot and root length decreased to the minimum?P<0.05?.Among the salt tolerance resistance for 5 tall fescue strains,the sequences were as follow,Tar Heel?>Watchdog>Ruby?>Baker>Super Watchdog.2.Organic silicon spraying had no significant effect on germination?such as germination rate,germination index and seed vigor index?of tall fescue seeds under salt stress,but promoted the growth of tall fescue seedlings and root system.The direct addition of organic silicon in soil could not alleviate the negative effects of salt stress on the germination of tall fescue seeds.On the contrary,it inhibited the germination of tall fescue,and reduced the germination rate,germination potential and seed vigor index.3.Salt stress resulted in increased cell membrane permeability,increased malondialdehyde and proline content in the leaves of tall fescue,decreased root activity and lawn quality established by Festuca arundinacea.The spraying of organic silicon effectively alleviated the damage of salt stress in higher concentration of sodium chloride,Such as reducing the permeability of the film,decreasing the proline content in the leaf tissues in the tall fescue,while increasing the leaf chlorophyll content,enhancing plant root system viability,and finally increasing turfgrass quality.