Allelopathy Of Lolium Perenne Aqueous Extract On Zoysia Japonica Steud.

Perennial ryegrass+warm season turfgrass are commonly used to establish evergreen Turfgrass in the transition zone,but it is often difficult for warm season turfgrass to turn green in spring.Pruning,grass combing,fertilization and other measures have been taken to promote the rejuvenation of warm season turfgrass,but the difficulty of rejuvenation of warm season turfgrass has not been completely eliminated.Some scholars have found that ryegrass can produce allelopathy inhibition,so the Allelopathy of ryegrass may affect the rejuvenation of warm season turfgrass in spring.In view of this,this study used three test methods of seed germination,pot culture and hydroponics to compare the effects of water extract of perennial ryegrass"MC Grady"with different concentrations on the seed germination,seedling growth and stolon growth of Zoysia japonica Steud,and to explore the reasons for the difficulty of Zoysia japonica returning to green in spring from the perspective of plant allelopathy.The main results are as follows:（1）The experiment of seed germination and seedling growth used Z.Hance as materials,and treated the seeds and seedlings of Z.Hance with 0,5,10,20,40,80 mg·m L^-1 perennial ryegrass aqueous extract.The results showed that:the water extract of perennial ryegrass inhibited the germination of Z.Hance seeds,and the concentration of 80 mg·m L^-1significantly reduced the germination rate of Z.Hance seeds by 27.36%compared with the control.High concentration of perennial ryegrass aqueous extract significantly reduced the fresh weight,seedling height,root length and chlorophyll content of Z.Hance seedlings,significantly increased the POD,CAT enzyme activities and MDA content of seedlings,the SOD enzyme activities showed the phenomenon of"low promotion and high inhibition"with the increase of treatment concentration.80 mg·m L^-1 significantly inhibited the growth of Z.Hance seedlings.Compared with the control,root length decreased by 80.46%and MDA content increased by 10.84%.（2）In the pot experiment,the stolons of Z."Lanyin No.3"were treated with 0,0.2,0.4,0.6,0.8,1.0 mg·m L^-1 water extract of perennial ryegrass.The results showed that:the water extract of perennial ryegrass significantly reduced the fresh weight,tiller number,root length,leaf length and other indexes of Z."Lanyin No.3"stolon,and significantly increased the leaf length width ratio;The thickness of upper and lower epidermis cuticle,the thickness of upper and lower epidermis cells,the diameter of vascular bundle,the diameter of main and lateral veins and the width of vesicular cells decreased significantly in Z."Lanyin No.3"Leaves;The chlorophyll content was significantly reduced,and the POD enzyme activity,MDA content and relative conductivity were significantly increased.With the increase of treatment concentration,the activities of CAT and SOD in stolons showed a trend of"low promotion and high inhibition".Under the treatment of 0.6 and 0.8 g·m L^-1,the stolon of Z."Lanyin No.3"was significantly allelopathic.Compared with the control,the total root length decreased by 75.51%,the length width ratio of leaves increased by 53.62%,the MDA content increased by 80.5%,and the maximum relative conductivity increased by 77.93%.（3）The stolon of Z."Lanyin No.3"was used as the material in the hydroponic culture experiment,and treated with 0,0.2,0.4,0.6,0.8,1.0 g·m L^-1 perennial ryegrass aqueous extract.The results showed that:the water extract of perennial ryegrass significantly reduced the stolon fresh weight,leaf length,leaf number,leaf width,leaf area and leaf perimeter of Z."Lanyin No.3";The length and surface area of roots were significantly decreased,but the volume and diameter of roots were not significantly decreased;the chlorophyll content was significantly reduced,the POD enzyme activity,MDA content and relative conductivity were significantly increased,and the CAT enzyme and SOD enzyme activities showed the phenomenon of"low promotion and high inhibition".Under the treatment of 0.6 and 0.8g·m L^-1,the stolon of Z."Lanyin No.3"was significantly inhibited by allelopathy.Compared with the control,the root length decreased by 93.00%,the leaf length width ratio increased by 56.79%,the MDA content increased by 89.81%,and the relative conductivity increased by 114.73%.In conclusion,the water extract of perennial ryegrass inhibited the seed germination and seedling growth of Z.Hance,inhibited the stolon growth of Z."Lanyin No.3",and then hindered the rejuvenation of Zoysia japonica in spring.