Evaluation On Adaptability Of Several Native Forage In Desert Steppe Of Ningxia

The characteristics of native plants such as drought tolerance and strong adaptability are expected to become an important material basis for grassland ecological construction.The unique natural climatic conditions of desert grass in Ningxia distribute a lot of excellent native plants.Carrying out relevant research on the adaptability of native plants can provide a basis for the further development and utilization of native grasses.In this study,the main native plants of Ningxia desert grassland are Agropyron mongolicum Keng(domestication)?Agropyron mongolicum Keng(new)?Agropyron mongolicum Keng?Lespedeza potaninii Vass?Astragalus melilotoides Through indoor control experiments and field cultivation experiments The effects of different treatment methods on seed germination characteristics,drought stress on the growth and physiological changes of different native pastures,native pasture growth and forage traits were studied,and their drought resistance and growth adaptability were synthesized through membership function method and gray correlation theory.Evaluation.The main conclusions are as follows:(1)Germination test showed that pre-cooling,gibberellic acid and potassium nitrate treatment had no significant effect on the germination traits of Agropyron mongolicum Keng(new)and Agropyron mongolicum Keng(domestication)seeds(P>0.05);potassium nitrate treatment could be significant Improve the germination rate of Agropyron mongolicum Keng(P<0.05);rubbing the seed coat and concentrated sulfuric acid treatment can effectively remove the hard seeds of Lespedeza potaninii Vass?Astragalus melilotoides seeds,improve the germination rate,germination potential and germination index.(2)With the increase of drought stress,the plant height of various forages decreased to varying degrees,the root-to-root ratio increased(P<0.05),the content of chlorophyll was significantly reduced,and the content of malondialdehyde and proline were significant Increasing trend;with the increase of drought stress,the SOD content of the three Agropyron mongolicum Keng showed that the upward trend was not obvious after the beginning of the increase.The POD content increased slowly under mild drought and increased violently under moderate and severe conditions.(3)The drought resistance evaluated by the membership function method is:Agropyron mongolicum Keng>Agropyron mongolicum Keng(domestication)>Agropyron mongolicum Keng(new)>Lespedeza potaninii Vass>Astragalus melilotoides.(4)Compared with the three Agropyron mongolicum Keng,Lespedeza potaninii Vass and Astragalus melilotoides have higher yield,higher growth rate,larger leaf-to-stem ratio,fresh and dry,and more underground biomass(P<0.05);three Agropyron mongolicum Keng The net photosynthetic rate of icegrass was significantly higher than that of Lespedeza potaninii Vass and Astragalus melilotoides,but the intercellular CO2 concentration was significantly less than that of the two legumes;there was no significant difference in the stomatal conductance and transpiration rate of each forage(P>0.05);Astragalus melilotoides has the highest crude protein content and low ADF and NDF content.The top three forages in the RFV are:Astragalus melilotoides,Agropyron mongolicum Keng(domestication),Agropyron mongolicum Keng.(5)With the help of the grey correlation method,the evaluation of agronomic traits,nutritional quality and photosynthetic characteristics found that the adaptability of forages is as follows:Astragalus melilotoides>Agropyron mongolicum Keng(domestication)>Lespedeza potaninii Vass>Agropyron mongolicum Keng>Agropyron mongolicum Keng(new).The study concluded that among the tested materials,Agropyron mongolicum Keng(domestication)has the strongest drought resistance,the nutritional quality of Astragalus melilotoides,and the best photosynthetic physiology.These two forages can be used as the preferred grass species in the ecological construction of desert grassland in Ningxia.