| Psathyrostachys juncea plays an important role in artificial grassland establishment and vegetative restoration in the cold and arid grassland areas of northern China because of the good winter tolerance,drought tolerance and persistence.However,the seed production of P.juncea is affected by factors such as short flowering period,unstable seed yield,and intolerant storage,which lead to difficulties in seed production and storage,and also restrict the further promotion and utilization of this valuable perennial grass.In this research,a systematically studied was conducted to analysis the key technology of seed production,including flowering habit,fertilization,regulating chemicals,storage condition and stale seed trigger.The experimental material for fertilization and spraying of growth regulator was P.juncea Mengnong No.4.Diammonium phosphate was applied in spring after greening.Paclobutrazol was treated at heading stage and foliar spray was carried out with different concentration solutions.No fertilization was used as the control,each treatment had 3 replicates,and the seeds were randomly divided into groups,and the seed yield and other indicators were determined after their maturity.The seed storage and aging test materials were P.juncea Mengnong No.4,P.juncea Mengnong No.5,P.juncea and P.juncea Shandan,and the seed vigor was determined.The main results are as follows.(1)The whole flowering duration of P.juncea is about 15～16 days,the flowering duration of single plant is about 14～15 days,and the flowering duration of single spike is about 10～12 days.Spike bloom start from top 1/3 position,then goes up and down simultaneously.Both illumination and temperature can affect the flowering of P.juncea,and the flowering number increased with rising of temperature.Peak time of pollen release is from 11:30 to 13:00.The population reaches full flowering on May 29.(2)The effects of fertilization and different concentrations of growth regulators on seed yield and seed yield components were determined by applying diammonium phosphate(DAP)in spring and foliar spraying paclobutrazol at heading stage.The results showed that DAP and paclobutrazol both had significant effects on seed yield.The actual seed yield reached the highest when the amount of DAP was 400kg/hm~2,followed by spraying paclobutrazol of 400mg/L.and the seed yield decreased with the increase of paclobutrazol concentration.(3)Spring fertilization and the use of growth regulators also had certain effects on seed vigor of P.juncea.At the optimum germination temperature of 25℃,the germination and seed vigor of the seeds harvested by spraying paclobutrazol 800mg/L and applying DAP 600kg/hm~2were the best.At 20℃and at low temperature of 15℃,the germination of seeds harvested by spraying paclobutrazol 400mg/L and applying DAP 600kg/hm~2treatment was the best.(4)Under different storage conditions and storage time,the germination effect of P.junces seeds is the best when stored in sealed bag at 5℃for 1 month,and stored in glass bottle at room temperature for 4 months.The germination rate of Mengnong No.5 reached the highest 3 months to 4 months after harvesting.The germination rate of Mengnong No.4was the highest 3 months after harvesting.The germination rate of the new strain reached the highest 2 months after harvesting.The seeds of Mengnong No.5 had the strongest vigor at 3 months after harvest,and the new strain had the strongest vigor at 4 months after harvest.For the old P.junces seeds stored for 6 years,the best treatment effect is to soak the seeds with penicillin.In conclusion,the main meteorological factor affecting the flowering of P.junces is temperature.The higher the temperature,the more flowering spikelets,When the temperature is 19℃,P.junces begins to bloom,the number of florets reached the maximum when the temperature reached 31℃.The application of nitrogen,phosphorus fertilizer and spray paclobutrazol in the heading stage can increase the seed yield of and improve the seed vigor.For safe storage,it is necessary to choose a suitable storage container and corresponding temperature.Seed soaking treatment by penicillin can improve the germination rate of P.junces old seeds in a certain extent. |
